S3C4510B01-QER0 [SAMSUNG]
Micro Peripheral IC, PQFP208,;
| 型号： | S3C4510B01-QER0 |
| 厂家： | 
SAMSUNG |
| 描述： | Micro Peripheral IC, PQFP208, |
| 文件： | 总422页 (文件大小：2160K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
S3C4510B
PRODUCT OVERVIEW
1
PRODUCT OVERVIEW
OVERVIEW
Samsung's S3C4510B 16/32-bit RISC microcontroller is a cost-effective, high-performance microcontroller
solution for Ethernet-based systems. An integrated Ethernet controller, the S3C4510B, is designed for use in
managed communication hubs and routers.
The S3C4510B is built around an outstanding CPU core: the 16/32-bit ARM7TDMI RISC processor designed by
Advanced RISC Machines, Ltd. The ARM7TDMI core is a low-power, general purpose microprocessor macro-cell
that was developed for use in application-specific and custom-specific integrated circuits. Its simple, elegant, and
fully static design is particularly suitable for cost-sensitive and power-sensitive applications.
The S3C4510B offers a configurable 8K-byte unified cache/SRAM and Ethernet controller which reduces total
system cost. Most of the on-chip function blocks have been designed using an HDL synthesizer and the
S3C4510B has been fully verified in Samsung's state-of-the-art ASIC test environment.
Important peripheral functions include two HDLC channels with buffer descriptor, two UART channels, 2-channel
GDMA, two 32-bit timers, and 18 programmable I/O ports. On-board logic includes an interrupt controller, DRAM/
SDRAM controller, and a controller for ROM/SRAM and flash memory. The System Manager includes an internal
32-bit system bus arbiter and an external memory controller.
The following integrated on-chip functions are described in detail in this user's manual:
— 8K-byte unified cache/SRAM
— I2C interface
— Ethernet controller
— HDLC
— GDMA
— UART
— Timers
— Programmable I/O ports
— Interrupt controller
1-1
PRODUCT OVERVIEW
S3C4510B
FEATURES
Architecture
·
·
·
·
·
·
·
·
·
·
Data alignment logic
·
Integrated system for embedded ethernet
applications
Endian translation
100/10-Mbit per second operation
·
·
Fully 16/32-bit RISC architecture
Full compliance with IEEE standard 802.3
MII and 7-wire 10-Mbps interface
Station management signaling
On-chip CAM (up to 21 destination addresses)
Full-duplex mode with PAUSE feature
Long/short packet modes
Little/Big-Endian mode supported basically, the
internal architecture is big-endian.
So, the little-endian mode only support for
external memory.
·
·
·
Efficient and powerful ARM7TDMI core
Cost-effective JTAG-based debug solution
Boundary scan
PAD generation
System Manager
HDLCs
·
8/16/32-bit external bus support for
ROM/SRAM, flash memory, DRAM, and
external I/O
·
HDLC protocol features:
— Flag detection and synchronization
— Zero insertion and deletion
·
One external bus master with bus request/
acknowledge pins
— Idle detection and transmission
— FCS generation and detection (16-bit)
— Abort detection and transmission
·
·
·
·
Support for EDO/normal or SDRAM
Programmable access cycle (0-7 wait cycles)
Four-word depth write buffer
·
·
·
·
·
·
Address search mode (expandable to 4 bytes)
Selectable CRC or No CRC mode
Automatic CRC generator preset
Digital PLL block for clock recovery
Baud rate generator
Cost-effective memory-to-peripheral DMA
interface
Unified Instruction/Data Cache
·
·
·
Two-way, set-associative, unified 8K-byte cache
Support for LRU (least recently used) protocol
Cache is configurable as an internal SRAM
NRZ/NRZI/FM/Manchester data formats for
Tx/Rx
·
·
·
·
·
·
·
·
·
·
Loop-back and auto-echo modes
Tx/Rx FIFOs have 8-word (8 ´ 32-bit) depth
Selectable 1-word or 4-word data transfer mode
Data alignment logic
I2C Serial Interface
·
·
Master mode operation only
Baud rate generator for serial clock generation
Endian translation
Programmable interrupts
Ethernet Controller
Modem interface
·
·
DMA engine with burst mode
Up to 10 Mbps operation
DMA Tx/Rx buffers (256 bytes Tx, 256 bytes
Rx)
HDLC frame length based on octets
·
MAC Tx/Rx FIFO buffers (80 bytes Tx, 16 bytes
Rx)
2-channel DMA buffer descriptor for Tx/Rx on
each HDLC
1-2
S3C4510B
PRODUCT OVERVIEW
DMA Controller
Programmable I/O
·
2-channel General DMA for memory-to-
memory, memory-to-UART, UART-to-memory
data transfers without CPU intervention
·
·
18 programmable I/O ports
Pins individually configurable to input, output, or
I/O mode for dedicated signals
·
·
Initiated by a software or external DMA request
Interrupt Controller
Increments or decrements a source or
destination address in 8-bit, 16-bit or 32-bit data
transfers
·
21 interrupt sources, including 4 external
interrupt sources
·
4-data burst mode
·
·
Normal or fast interrupt mode (IRQ, FIQ)
Prioritized interrupt handling
UARTs
·
Two UART (serial I/O) blocks with DMA-based
or interrupt-based operation
PLL
·
The external clock can be multiplied by on-chip
·
Support for 5-bit, 6-bit, 7-bit, or 8-bit serial data
transmit and receive
PLL to provide high frequency system clock
·
·
The input frequency range is 10–40 MHz
·
·
·
·
·
·
·
Programmable baud rates
1 or 2 stop bits
The output frequency is 5 times of input clock.
To get 50 MHz, input clock frequency should be
10 MHz.
Odd or even parity
Break generation and detection
Parity, overrun, and framing error detection
´ 16 clock mode
Operating Voltage Range
3.3 V ± 5 %
·
Infra-red (IR) Tx/Rx support (IrDA)
Operating Temperature Range
° °
0 C to + 70 C
·
Timers
·
·
Two programmable 32-bit timers
Interval mode or toggle mode operation
Operating Frequency
Up to 50 MHz
·
Package Type
208-Pin QFP
·
1-3
PRODUCT OVERVIEW
S3C4510B
ARM7TDMI
32-bit RISE CPU
ICE-
Breaker
6-bank
ROM
SRAM
FLASH
32-Bit
Sytem
Bus
CPU Interface
4-bank
DRAM
Memory
Controller
with
Refresh
Control
8-Kbyte
Unified
Cache
4-bank
External
I/O
Device
4-Word
Write
Buffer
Ext Bus
REQ/ACK
External
Bus
Master
System
Bus
Arbiter
Bus Rounter
I2C
2-Channel HDLCs
with DMAs
Remote
port A,B
SCL
SDA
Ethernet Controller
2-channel BDMA
18 I/O Ports including
4: Ext INT req.
2: Timer out (0,1)
2: Ext DMA REQ.
2: Ext DMA ACK
18 General I/O ports
Interruput Controller
UART 0,1
BDMA RAMs
Tx Buffer (256 bytes)
Rx Buffer (256 bytes)
CAM (128 bytes)
Console
32-bit Timer 0,1
GDMA 0,1
MAC
Tx FIFO (80 bytes)
Rx FIFO (16 bytes)
MII or
7-wire
PLL
Xtal OSC
TAP Controller for JTAG
Figure 1-1. S3C4510B Block Diagram
1-4
S3C4510B
PRODUCT OVERVIEW
156
155
154
153
152
151
150
149
148
147
146
145
144
143
142
141
140
139
138
137
136
135
134
133
132
131
130
129
128
127
126
125
124
123
122
121
120
119
118
117
116
115
114
113
112
111
110
109
VDD
VSS
VDD
VSS
1
2
3
4
5
6
7
8
XDATA<16>
XDATA<15>
XDATA<14>
XDATA<13>
XDATA<12>
XDATA<11>
XDATA<10>
XDATA<9>
XDATA<8>
XDATA<7>
XDATA<6>
VSS
nUADTR1
UATXD1
nUADSR1
nDTRA
RXDA
nRTSA
TXDA
nCTSA
VDD
VSS
nDCDA
RXCA
nSYNCA
TXCA
nDTRB
RTDB
nRTSB
TXDB
VDD
VSS
nCTSB
nDCDB
RXCB
nSYNCB
TXCB
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
VDD
XDATA<5>
XDATA<4>
XDATA<3>
XDATA<2>
XDATA<1>
XDATA<0>
XDATA<21>
XDATA<20>
XDATA<19>
XDATA<18>
VSS
S3C4510B
208-QFP
VDD
ADDR<17>
ADDR<16>
ADDR<15>
ADDR<14>
ADDR<13>
ADDR<12>
ADDR<11>
ADDR<10>/AP
ADDR<9>
ADDR<8>
VSS
CRS/CRS_ 10M
RX DV/LINK_10M
RXD<0>/RXD_10M
VDD
VSS
RXD<1>
RXD<2>
RXD<3>
RX ERR
RX_CLK/RXCLK_10M
COL/COL_10M
TXD<0>/TXD_10M
TXD<1>/LOOP_10M
VDD
VDD
ADDR<7>
ADDR<6>
ADDR<5>
ADDR<4>
ADDR<3>
ADDR<2>
ADDR<1>
ADDR<0>
ExtMACK
VSS
TXD<2>
TXD<3>
TX_ERR/POCMP_10M
TX_CLK/TXCLK_10M
TX_EN/TXEN_10M
MDIO
108
107
106
105
ExtMREQ
nWBE<3>/DQM<3>
VSS
LITTLE
MDC
VDD
49
50
51
52
VDD
VSS
Figure 1-2. S3C4510B Pin Assignment Diagram
1-5
PRODUCT OVERVIEW
S3C4510B
SIGNAL DESCRIPTIONS
Table 1-1. S3C4510B Signal Descriptions
Signal
Pin No.
Type
Description
XCLK
80
I
S3C4510B system clock source. If CLKSEL is Low, PLL output
clock is used as the S3C4510B internal system clock. If
CLKSEL is High, XCLK is used as the S3C4510B internal
system clock.
MCLKO/SDCLK (note)
CLKSEL
77
83
82
O
I
System clock out. MCLKO is monitored with some delay as the
same phase of internal system clock, MCLK(SCLK).
SDCLK is system clock for SDRAM.
Clock select. When CLKSEL is '0'(low level), PLL output clock
can be used as the master clock. When CLKSEL is '1'(high
level), the XCLK is used as the master clock.
nRESET
I
Not reset. nRESET is the global reset input for the S3C4510B.
To allow a system reset, and for internal digital filtering,
nRESET must be held to low level for at least 64 master clock
cycles. Refer to "Figure 3. S3C4510B reset timing diagram" for
more details about reset timing.
CLKOEN
TMODE
76
63
I
I
Clock out enable/disable. (see the pin description for MCLKO.)
Test Mode. The TMODE bit settings are interpreted as follows:
'0' = normal operating mode, '1' = chip test mode.
This TMODE pin also can be used to change MF of PLL.
To get 5 times internal system clock from external clock, '0'(low
level) should be assigned to TMODE. If '1'(high level), MF will
be changed to 6.6
FILTER
TCK
55
58
AI
I
If the PLL is used, 820pF ceramic capacitor should be
connected between the pin and analog ground(pin # 54).
JTAG Test Clock. The JTAG test clock shifts state information
and test data into, and out of, the S3C4510B during JTAG test
operations. This pin is internally connected pull-down.
TMS
TDI
59
60
I
I
JTAG Test Mode Select. This pin controls JTAG test operations
in the S3C4510B. This pin is internally connected pull-up.
JTAG Test Data In. The TDI level is used to serially shift test
data and instructions into the S3C4510B during JTAG test
operations. This pin is internally connected pull-up.
TDO
61
62
O
I
JTAG Test Data Out. The TDO level is used to serially shift test
data and instructions out of the S3C4510B during JTAG test
operations.
nTRST
JTAG Not Reset. Asynchronous reset of the JTAG logic.
This pin is internally connected pull-up.
1-6
S3C4510B
PRODUCT OVERVIEW
Table 1-1. S3C4510B Signal Descriptions (Continued)
Signal
Pin No.
Type
Description
ADDR[21:0]/
ADDR[10]/AP (note)
117–110,
129–120,
135–132
O
Address Bus. The 22-bit address bus, ADDR[21:0], covers the full
4M word address range of each ROM/SRAM, flash memory,
DRAM, and the external I/O banks.
The 23-bit internal address bus used to generate DRAM address.
The number of column address bits in DRAM bank can be
programmed 8bits to 11bits use by DRAMCON registers.
ADDR[10]/AP is the auto precharge control pin. The auto
precharge command is issued at the same time as burst read or
burst write by asserting high on ADDR[10]/AP.
XDATA[31:0]
141–136,
154–144,
166–159,
175–169
I/O
External (bi-directional, 32-bit) Data Bus. The S3C4510B data
bus supports external 8-bit, 16-bit, and 32-bit bus sizes.
nRAS[3:0]/
94, 91, 90,
89
O
O
Not Row Address Strobe for DRAM. The S3C4510B supports up
to four DRAM banks. One nRAS output is provided for each
bank. nSDCS[3:0] are chip select pins for SDRAM.
nSDCS[3:0] (note)
nCAS[3:0]
98, 97, 96,
95
Not column address strobe for DRAM. The four nCAS outputs
indicate the byte selections whenenver a DRAM bank is
accessed. nSDRAS is row address strobe signal for SDRAM.
Latches row addresses on the positive going edge of the SDCLK
with nSDRAS low. Enable row access and precharge. nSDCAS is
column address strobe for SDRAM. Latches column addresses
on the positive going edge of the SDCLK with nSDCAS low.
Enables column access. CKE is clock enable signal for SDRAM.
Masks SDRAM system clock, SDCLK to freeze operation from
the next clock cycle. SDCLK should be enabled at least one cycle
prior to new command. Disable input buffers of SDRAM for
power down in standby.
nCAS[0]/nSDRAS
nCAS[1]/nSDCAS
nCAS[2]/CKE (note)
nDWE
99
O
O
DRAM Not Write Enable. This pin is provided for DRAM bank
write operations. (nWBE[3:0] is used for write operations to the
ROM/ SRAM/flash memory banks.) .
nECS[3:0]
70, 69, 68,
67
Not External I/O Chip Select. Four external I/O banks are
provided for external memory-mapped I/O operations. Each I/O
bank stores up to 16 Kbytes. nECS signals indicate which of the
four external I/O banks is selected.
nEWAIT
71
I
Not External Wait. This signal is activated when an external I/O
device or ROM/SRAM/flash bank 5 needs more access cycles
than those defined in the corresponding control register.
When de-assert the nEWAIT, you must synchronize the nEWAIT
with MCLKO rising edge. If not, memory state machine can get
into the Wrong State.
1-7
PRODUCT OVERVIEW
S3C4510B
Table 1-1. S3C4510B Signal Descriptions (Continued)
Signal
Pin No.
Type
Description
nRCS[5:0]
88-84, 75
O
Not ROM/SRAM/Flash Chip Select. The S3C4510B can access
up to six external ROM/SRAM/Flash banks. By controlling the
nRCS signals, you can map CPU addresses into the physical
memory banks.
B0SIZE[1:0]
nOE
74, 73
72
I
Bank 0 Data Bus Access Size. Bank 0 is used for the boot
program. You use these pins to set the size of the bank 0 data
bus as follows: '01' = one byte, '10' = half-word, '11' = one word,
and '00' = reserved.
O
O
Not Output Enable. Whenever a memory access occurs, the nOE
output controls the output enable port of the specific memory
device.
nWBE[3:0]/
DQM[3:0] (note)
107,
102–100
Not Write Byte Enable. Whenever a memory write access
occurs, the nWBE output controls the write enable port of the
specific memory device (except for DRAM). For DRAM banks,
CAS[3:0] and nDWE are used for the write operation.
DQM is data input/output mask signal for SDRAM.
ExtMREQ
108
I
External Bus Master Request. An external bus master uses this
pin to request the external bus. When it activates the ExtMREQ
signal, the S3C4510B drives the state of external bus pins to high
impedance. This lets the external bus master take control of the
external bus. When it has the control, the external bus master
assumes responsibility for DRAM refresh operations. The
ExtMREQ signal is deactivated when the external bus master
releases the external bus. When this occurs, ExtMACK goes Low
level and the S3C4510B assumes the control of the bus.
ExtMACK
MDC
109
50
O
O
External Bus Acknowledge. (See the ExtMREQ pin description.)
Management Data Clock. The signal level at the MDC pin is used
as a timing reference for data transfers that are controlled by the
MDIO signal.
MDIO
48
I/O
Management Data I/O. When a read command is being
executed, data that is clocked out of the PHY is presented on this
pin. When a write command is being executed, data that is
clocked out of the controller is presented on this pin for the
Physical Layer Entity, PHY.
LITTLE
49
38
I
I
Little endian mode select pin. If LITTLE is High, S3C4510B
operate in little endian mode. If Low, then in Big endian mode.
Default value is low because this pin is pull-downed internally.
COL/COL_10M
Collision Detected/Collision Detected for 10M. COL is asserted
asynchronously with minimum delay from the start of a collision
on the medium in MII mode. COL_10M is asserted when a 10-
Mbit/s PHY detects a collision.
TX_CLK/
TXCLK_10M
46
I
Transmit Clock/Transmit Clock for 10M. The controller drives
TXD[3:0] and TX_EN from the rising edge of TX_CLK. In MII
mode, the PHY samples TXD[3:0] and TX_EN on the rising edge
of TX_CLK. For data transfers, TXCLK_10M is provided by the
10-Mbit/s PHY.
1-8
S3C4510B
PRODUCT OVERVIEW
Table 1-1. S3C4510B Signal Descriptions (Continued)
Signal
Pin No.
Type
Description
TXD[3:0]
LOOP_10M
TXD_10M
44, 43, 40,
39
O
Transmit Data/Transmit Data for 10 M/Loop-back for 10M.
Transmit data is aligned on nibble boundaries. TXD[0]
corresponds to the first bit to be transmitted on the physical
medium, which is the LSB of the first byte and the fifth bit of that
byte during the next clock. TXD_10M is shared with TXD[0] and
is a data line for transmitting to the 10-Mbit/s PHY. LOOP_10M is
shared with TXD[1] and is driven by the loop-back bit in the
control register.
TX_EN/
TXEN_10M
47
45
O
O
Transmit Enable/Transmit Enable for 10M. TX_EN provides
precise framing for the data carried on TXD[3:0]. This pin is
active during the clock periods in which TXD[3:0] contains valid
data to be transmitted from the preamble stage through CRC.
When the controller is ready to transfer data, it asserts
TXEN_10M.
TX_ERR/
PCOMP_10M
Transmit Error/Packet Compression Enable for 10M. TX_ERR is
driven synchronously to TX_CLK and sampled continuously by
the Physical Layer Entity, PHY. If asserted for one or more
TX_CLK periods, TX_ERR causes the PHY to emit one or more
symbols which are not part of the valid data, or delimiter set
located somewhere in the frame that is being transmitted.
PCOMP_10M is asserted immediately after the packet's DA field
is received. PCOMP_10M is used with the Management Bus of
the DP83950 Repeater Interface Controller (from National
Semiconductor). The MAC can be programmed to assert
PCOMP if there is a CAM match, or if there is not a match. The
RIC (Repeater Interface Controller) uses this signal to compress
(shorten) the packet received for management purposes and to
reduce memory usage. (See the DP83950 Data Sheet, published
by National Semiconductor, for details on the RIC Management
Bus.). This pin is controlled by a special register, with which you
can define the polarity and assertion method (CAM match active
or not match active) of the PCOMP signal.
CRS/CRS_10M
28
37
I
I
Carrier Sense/Carrier Sense for 10M. CRS is asserted
asynchronously with minimum delay from the detection of a non-
idle medium in MII mode. CRS_10M is asserted when a 10-
Mbit/s PHY has data to transfer. A 10-Mbit/s transmission also
uses this signal.
RX_CLK/
RXCLK_10M
Receive Clock/Receive Clock for 10M. RX_CLK is a continuous
clock signal. Its frequency is 25 MHz for 100-Mbit/s operation,
and 2.5 MHz for 10-Mbit/s. RXD[3:0], RX_DV, and RX_ERR are
driven by the PHY off the falling edge of RX_CLK, and sampled
on the rising edge of RX_CLK. To receive data, the TXCLK_10 M
clock comes from the 10-Mbit/s PHY.
RXD[3:0]/
RXD_10M
35, 34, 33,
30
I
Receive Data/Receive Data for 10M. RXD is aligned on nibble
boundaries. RXD[0] corresponds to the first bit received on the
physical medium, which is the LSB of the byte in one clock
period and the fifth bit of that byte in the next clock. RXD_10M is
shared with RXD[0] and it is a line for receiving data from the 10-
Mbit/s PHY.
1-9
PRODUCT OVERVIEW
S3C4510B
Table 1-1. S3C4510B Signal Descriptions (Continued)
Signal
Pin No.
Type
Description
RX_DV/LINK_10M
29
I
Receive Data Valid/Link Status for 10M. PHY asserts RX_DV
synchronously, holding it active during the clock periods in which
RXD[3:0] contains valid data received. PHY asserts RX_DV no
later than the clock period when it places the first nibble of the
start frame delimiter (SFD) on RXD[3:0]. If PHY asserts RX_DV
prior to the first nibble of the SFD, then RXD[3:0] carries valid
preamble symbols. LINK_10M is shared with RX_DV and used to
convey the link status of the 10-Mbit/s endec. The value is stored
in a status register.
RX_ERR
36
I
Receive Error. PHY asserts RX_ERR synchronously whenever it
detects a physical medium error (e.g., a coding violation). PHY
asserts RX_ERR only when it asserts RX_DV.
TXDA
RXDA
9
7
O
I
HDLC Ch-A Transmit Data. The serial output data from the
transmitter is coded in NRZ/NRZI/FM/Manchester data format.
HDLC Ch-A Receive Data. The serial input data received by the
device should be coded in NRZ/NRZI/FM/Manchester data
format. The data rate should not exceed the rate of the
S3C4510B internal master clock.
nDTRA
nRTSA
6
8
O
O
HDLC Ch-A Data Terminal Ready. nDTRA output indicates that
the data terminal device is ready for transmission and reception.
HDLC Ch-A Request To Send. The nRTSA output goes low when
there is exist data to be sent in TxFIFO. The data to be sent is
transmitted when the nCTS is active(Low) state.
nCTSA
nDCDA
10
13
I
I
HDLC Ch-A Clear To Send. The S3C4510B stores each
transition of nCTS to ensure that its occurrence would be
acknowledged by the system.
HDLC Ch-A Data Carrier Detected. A High level on this pin resets
and inhibits the receiver register. Data from a previous frame that
may remain in the RxFIFO is retained. The S3C4510B stores
each transition of nDCD.
nSYNCA
RXCA
15
14
O
I
HDLC Ch-A Sync is detected. This indicates the reception of a
flag. The nSYNC output goes low for one bit time beginning at
the last bit of the flag.
HDLC Ch-A Receiver Clock. When this clock input is used as the
receiver clock, the receiver samples the data on the positive
edge of RXCA clock. This clock can be the source clock of the
receiver, the baud rate generator, or the DPLL.
TXCA
16
I/O
HDLC Ch-A Transmitter Clock. When this clock input is used as
the transmitter clock, the transmitter shifts data on the negative
transition of the TXCA clock . If you do not use TXCA as the
transmitter clock, you can use it as an output pin for monitoring
internal clocks such as the transmitter clock, receiver clock, and
baud rate generator output clocks.
TXDB
RXDB
20
18
O
I
HDLC Ch-B transmit data. See the TXDA pin description.
HDLC Ch-B receive data. See the RXDA pin description.
1-10
S3C4510B
PRODUCT OVERVIEW
Table 1-1. S3C4510B Signal Descriptions (Continued)
Signal
Pin No.
17
Type
Description
nDTRB
nRTSB
nCTSB
nDCDB
O
O
I
HDLC Ch-B data terminal ready. See the nDTRA pin description.
HDLC Ch-B request to send. See the nRTSA pin description.
HDLC Ch-B clear to send. See the nCTSA pin description.
19
23
24
I
HDLC Ch-B data carrier detected. See the nDCDA pin
description.
nSYNCB
RXCB
TXCB
26
25
27
64
O
I
HDLC Ch-B sync is detected. See the nSYNCA pin description.
HDLC Ch-B receiver clock. See the RXCA pin description.
HDLC Ch-B transmitter clock. See the TXCA pin description.
I/O
I
UCLK
The external UART clock input. MCLK or PLL generated clock
can be used as the UART clock. You can use UCLK, with an
appropriate divided by factor, if a very precious baud rate clock is
required.
UARXD0
UATXD0
nUADTR0
202
204
203
I
O
I
UART0 receive data. RXD0 is the UART 0 input signal for
receiving serial data.
UART0 transmit data. TXD0 is the UART 0 output signal for
transmitting serial data.
Not UART0 data terminal ready. This input signals the S3C4510B
that the peripheral (or host) is ready to transmit or receive serial
data.
nUADSR0
205
O
Not UART0 data set ready. This output signals the host
(or peripheral) that UART 0 is ready to transmit or receive serial
data.
UARXD1
UATXD1
nUADTR1
nUADSR1
P[7:0]
206
4
I
O
I
UART1 receive data. See the RXD0 pin description.
UART1 transmit data. See the TXD0 pin description.
Not UART1 data terminal ready. See the DTR0 pin description.
Not UART1 data set ready. See the DSR0 pin description.
General I/O ports. See the I/O ports, chapter 12.
3
5
O
I/O
185–179,
176
XINTREQ[3:0]
P[11:8]
191–189,
186
I/O
I/O
I/O
External interrupt request lines or general I/O ports.
See the I/O ports, chapter 12.
nXDREQ[1:0]/
P[13:12]
193, 192
Not external DMA requests for GDMA or general I/O ports.
See the I/O ports, chapter 12.
nXDACK[1:0]
P[15:14]
195, 194
Not external DMA acknowledge from GDMA or general I/O ports.
See the I/O ports, chapter 12.
TOUT0/P[16]
TOUT1/P[17]
SCL
196
199
200
201
I/O
I/O
I/O
I/O
Timer 0 out or general I/O port. See the I/O ports, chapter 12.
Timer 1 out or general I/O port. See the I/O ports, chapter 12.
I2C serial clock.
SDA
I2C serial data.
1-11
PRODUCT OVERVIEW
S3C4510B
Table 1-1. S3C4510B Signal Descriptions (Continued)
Signal
Pin No.
Type
Description
VDDP
1, 21, 41, 56, 78,
92, 105, 118, 130,
155, 167, 177, 197
Power
I/O pad power
VDDI
11, 31, 51, 65,
103, 142, 157,
187, 207
Power
GND
Internal core power
I/O pad ground
VSSP
2, 22, 42, 57, 79,
81, 93, 106, 119,
131, 156, 168,
178, 198
VSSI
12, 32, 52, 66,
104, 143, 158,
188, 208
GND
Internal core ground
VDDA
53
54
Power
GND
Analog power for PLL
VSSA/VBBA
Analog/bulk ground for PLL
NOTE: SDRAM or EDO/normal DRAM interface signal pins are shared functions. It's functions will be configured by
SYSCFG[31].
1-12
S3C4510B
PRODUCT OVERVIEW
Table 1-2. S3C4510B Pin List and PAD Type
Group
Pin Name Pin Counts I/O Type
Pad Type
ptic
Description
System
XCLK
1
1
1
1
1
1
1
1
1
1
1
1
1
22
32
4
4
1
4
1
6
2
1
4
1
1
I
O
I
S3C4510B system source clock.
System clock out.
Configuration MCLKO
pob4
ptic
(8)
CLKSEL
nRESET
CLKOEN
TMODE
LITTLE
Clock select.
I
ptis
Not reset
I
ptic
Clock out enable/disable.
Test mode.
I
ptic
I
pticd
pia_bb
ptic
Little endian mode select pin
PLL filter pin
FILTER
I
TAP Control TCK
I
JTAG test clock.
(5)
TMS
I
pticu
pticu
ptot2
pticu
ptot6
ptbsut6
ptot4
ptot4
ptot4
ptot4
ptic
JTAG test mode select.
JTAG test data in.
TDI
I
TDO
O
I
JTAG test data out.
nTRST
JTAG not reset.
Memory
Interface
(83)
ADDR[21:0]
XDATA[31:0]
nRAS[3:0]
nCAS[3:0]
nDWE
O
I/O
O
O
O
O
I
Address bus.
External, bi-directional, 32-bit data bus.
Not row address strobe for DRAM.
Not column address strobe for DRAM.
Not write enable
nECS[3:0]
nEWAIT
nRCS[5:0]
B0SIZE[1:0]
nOE
Not external I/O chip select.
Not external wait signal.
Not ROM/SRAM/flash chip select.
Bank 0 data bus access size.
Not output enable.
O
I
ptot4
ptic
O
O
I
ptot4
ptot4
ptic
nWBE[3:0]
ExtMREQ
ExtMACK
Not write byte enable.
External master bus request.
External bus acknowledge.
O
pob1
1-13
PRODUCT OVERVIEW
S3C4510B
Table 1-2. S3C4510B Pin List and PAD Type (Continued)
Group
Ethernet
Controller
(18)
Pin Name Pin Counts I/O Type
Pad Type
pob4
Description
MDC
1
1
1
O
I/O
I
Management data clock.
Management data I/O.
MDIO
ptbcut4
ptis
COL/
Collision detected/collision detected for
10 M.
COL_10M
TX_CLK/
TXCLK_10M
1
4
I
ptis
Transmit data/transmit data for 10 M.
TXD[3:0]/
O
pob4
Transmit data/transmit data for 10 M.
TXD_10M
LOOP_10M
TX_EN/
TXEN_10M
I
O
O
I
pob4
pob4
ptis
Transmit enable or transmit enable for 10
M.
TX_ERR/
PCOMP_10M
1
1
1
4
1
Transmit error/packet compression
enable for 10 M.
CRS/
CRS_10M
Carrier sense/carrier sense for 10 M.
Receive clock/receive clock for 10 M.
Receive data/receive data for 10 M.
Receive data valid.
RX_CLK/
RXCLK_10M
I
ptis
RXD[3:0]/
RXD_10M
1
I
ptis
RX_DV/
ptis
LINK_10M
RX_ERR
TXDA
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
I
O
I
ptis
pob4
ptis
Receive error.
HDLC
Channel A
(9)
HDLC channel A transmit data.
HDLC channel A receive data.
HDLC channel A data terminal ready.
HDLC channel A request to send.
HDLC channel A clear to send.
HDLC channel A data carrier detected.
HDLC channel A sync is detected.
HDLC channel A receiver clock.
HDLC channel A transmitter clock.
HDLC channel B transmit data.
HDLC channel B receive data.
HDLC channel B data terminal ready.
HDLC channel B request to send.
HDLC channel B clear to send.
HDLC channel B data carrier detected.
HDLC channel B sync is detected.
HDLC channel B receiver clock.
HDLC channel B transmitter clock.
RXDA
nDTRA
nRTSA
nCTSA
nDCDA
nSYNCA
RXCA
O
O
I
pob4
pob4
ptis
I
ptis
O
I
pob4
ptis
TXCA
I/O
O
I
ptbsut1
pob4
ptis
HDLC
Channel B
(9)
TXDB
RXDB
nDTRB
nRTSB
nCTSB
nDCDB
nSYNCB
RXCB
O
O
I
pob4
pob4
ptis
I
ptis
O
I
pob4
ptis
TXCB
I/O
ptbsut1
1-14
S3C4510B
PRODUCT OVERVIEW
Table 1-2. S3C4510B Pin List and PAD Type (Continued)
Group
UART 0
(5)
Pin Name Pin Counts I/O Type
Pad Type
ptis
Description
UCLK
1
1
1
1
1
1
1
1
1
8
4
I
I
UART External Clock for UART0/UART1
UART 0 receive data.
UARXD0
UATXD0
nUADTR0
nUADSR0
UARXD1
UATXD1
nUADTR1
NUADSR1
P[7:0]
ptic
O
I
pob4
ptic
UART 0 transmit data.
Not UART 0 data terminal ready.
Not UART 0 data set ready.
UART 1 receive data.
O
I
pob4
ptic
UART 1
(4)
O
I
pob4
ptic
UART 1 transmit data.
Not UART 1 data terminal ready.
Not UART 1 data set ready.
O
I/O
I/O
pob4
General-
ptbst4sm General I/O ports.
Purpose I/O xINTREQ
(xINTREQ,
ptbst4sm External interrupt requests or general I/O
ports.
[3:0]/P[11:8]
nXDREQ,
nXDACK
2
2
1
1
I/O
I/O
I/O
I/O
ptbst4sm External DMA requests for GDMA or
general I/O ports.
xXDREQ
[1:0]/P[13:12]
Timer 0, 1)
(18)
ptbst4sm External DMA acknowledge from GDMA
or general I/O ports.
nXDACK[1:0]
/ P[15:14]
ptbst4sm Timer 0 out or general I/O port.
TIMER0/P
[16]
ptbst4sm Timer 1 out or general I/O port.
TIMER1/P
[17]
I2C
(2)
SCL
SDA
1
1
I/O
I/O
ptbcd4
ptbcd4
I2C serial clock.
I2C serial data.
1-15
PRODUCT OVERVIEW
Pad Type I/O Type
S3C4510B
Table 1-3. S3C4510B PAD Type
Cell Type
Current
Drive
Feature
Slew-Rate
Control
ptic
I
I
I
–
–
–
LVCMOS level
5 V-tolerant
5 V-tolerant
–
–
–
ptis
LVCMOS schmit trigger level
LVCMOS level
pticu
5 V-tolerant
Pull-up register
pticd
I
–
LVCMOS level
5 V-tolerant
–
Pull-down register
pia_bb
pob1
I
O
–
Analog input with seperate bulk bias
Normal buffer
–
–
–
–
–
–
–
–
1 mA
2 mA
4 mA
4 mA
6 mA
1 mA
–
ptot2
O
Tri-state buffer
5 V-tolerant
–
pob4
O
Normal buffer
ptot4
O
Tri-state buffer
5 V-tolerant
5 V-tolerant
ptot6
O
Tri-state buffer
ptbsut1
I/O
LVCMOS schmit trigger level
Tri-state buffer
5 V-tolerant
Pull-up register
ptbcut4
ptbcd4
I/O
I/O
I/O
I/O
4 mA
4 mA
4 mA
6 mA
LVCMOS level Tri-state buffer
LVCMOS level open drain buffer
LVCMOS schmit trigger level
LVCMOS schmit trigger level
5 V-tolerant
5 V-tolerant
5 V-tolerant
Medium
–
Medium
–
ptbst4sm
Ptbsut6
5 V-tolerant
Pull-up register
NOTE: pticu and pticd provides 100K Ohm Pull-up(down) register. For detail information about the pad type, see Chapter 4.
Input/Output Cells of the "STD90/MDL90 0.35 um 3.3 V Standard Cell Library Data Book", produced by Samsung
Electrionic Co., Ltd, ASIC Team.
nRESET
64*fMCLK
512*fMCLK
nRSCO
NOTE: After the falling edge of nRESET, the S3C4510B count 64 cycles for a system reset
and needs further 512 cycles for a TAG RAM clear of cache.
After these cycles, the S3C4510B asserts nRCS0 when the nRESET is released.
Figure 1-3. Reset Timing Diagram
1-16
S3C4510B
PRODUCT OVERVIEW
CPU CORE OVERVIEW
The S3C4510B CPU core is a general purpose 32-bit ARM7TDMI microprocessor, developed by Advanced RISC
Machines, Ltd. (ARM). The core architecture is based on Reduced Instruction Set Computer (RISC) principles.
The RISC architecture makes the instruction set and its related decoding mechanism simpler and more efficient
than those with microprogrammed Complex Instruction Set Computer (CISC) systems. High instruction
throughput and impressive real-time interrupt response are among the major beneifts of the architecture.
Pipelining is also employed so that all components of the processing and memory systems can operate
continuously. The ARM7TDMI has a 32-bit address bus.
An important feature of the ARM7TDMI processor that makes itself distinct from the ARM7 processor is a unique
architectural strategy called THUMB. The THUMB strategy is an extension of the basic ARM architecture
consisting of 36 instruction formats. These formats are based on the standard 32-bit ARM instruction set, while
having been re-coded using 16-bit wide opcodes.
As THUMB instructions are one-half the bit width of normal ARM instructions, they produce very high-density
codes. When a THUMB instruction is executed, its 16-bit opcode is decoded by the processor into its equivalent
instruction in the standard ARM instruction set. The ARM core then processes the 16-bit instruction as it would a
normal 32-bit instruction. In other words, the THUMB architecture gives 16-bit systems a way to access the 32-bit
performance of the ARM core without requiring the full overhead of 32-bit processing.
As the ARM7TDMI core can execute both standard 32-bit ARM instructions and 16-bit THUMB instructions, it
allows you to mix the routines of THUMB instructions and ARM code in the same address space. In this way, you
can adjust code size and performance, routine by routine, to find the best programming solution for a specific
application.
Address
Register
Address
Incrementer
Instruction
Register Bank
Decoder and
Logic Controll
Multiplier
Barrel
Shifter
32-Bit ALU
Instruction
Pipeline and Read
Data Register
Write Data
Register
Figure 1-4. ARM7TDMI Core Block Diagram
1-17
PRODUCT OVERVIEW
S3C4510B
INSTRUCTION SET
The S3C4510B instruction set is divided into two subsets: a standard 32-bit ARM instruction set and a 16-bit
THUMB instruction set.
The 32-bit ARM instruction set is comprised of thirteen basic instruction types, which can, in turn, be divided into
four broad classes:
·
·
·
Four types of branch instructions which control program execution flow, instruction privilege levels, and
switching between an ARM code and a THUMB code.
Three types of data processing instructions which use the on-chip ALU, barrel shifter, and multiplier to
perform high-speed data operations in a bank of 31 registers (all with 32-bit register widths).
Three types of load and store instructions which control data transfer between memory locations and the
registers. One type is optimized for flexible addressing, another for rapid context switching, and the third for
swapping data.
·
Three types of co-processor instructions which are dedicated to controlling external co-processors. These
instructions extend the off-chip functionality of the instruction set in an open and uniform way.
NOTE
All 32-bit ARM instructions can be executed conditionally.
The 16-bit THUMB instruction set contains 36 instruction formats drawn from the standard 32-bit ARM instruction
set. The THUMB instructions can be divided into four functional groups:
·
·
·
·
Four branch instructions.
Twelve data processing instructions, which are a subset of the standard ARM data processing instructions.
Eight load and store register instructions.
Four load and store multiple instructions.
NOTE
Each 16-bit THUMB instruction has a corresponding 32-bit ARM instruction with an identical
processing model.
The 32-bit ARM instruction set and the 16-bit THUMB instruction set are good targets for compilers of many
different high-level languages. When an assembly code is required for critical code segments, the ARM
programming technique is straightforward, unlike that of some RISC processors which depend on sophisticated
compiler technology to manage complicated instruction interdependencies.
Pipelining is employed so that all parts of the processor and memory systems can operate continuously.
Typically, while one instruction is being executed, its successor is being decoded, and the third instruction is
being fetched from memory.
1-18
S3C4510B
PRODUCT OVERVIEW
MEMORY INTERFACE
The CPU memory interface has been designed to help the highest performance potential to be realized without
incurring high costs in the memory system. Speed-critical control signals are pipelined so that system control
functions can be implemented in standard low-power logic. These pipelined control signals allow you to fully
exploit the fast local access modes, offered by industry standard dynamic RAMs.
OPERATING STATES
From a programmer¢s point of view, the ARM7TDMI core is always in one of two operating states. These states,
which can be switched by software or by exception processing, are:
·
·
ARM state (when executing 32-bit, word-aligned, ARM instructions), and
THUMB state (when executing 16-bit, half-word aligned THUMB instructions).
OPERATING MODES
The ARM7TDMI core supports seven operating modes:
·
·
·
·
·
·
·
User mode: a normal program execution state
FIQ (Fast Interrupt Request) mode: for supporting a specific data transfer or channel processing
IRQ (Interrupt ReQuest) mode: for general purpose interrupt handling
Supervisor mode: a protected mode for the operating system
Abort mode: entered when a data or instruction pre-fetch is aborted
System mode: a privileged user mode for the operating system
Undefined mode: entered when an undefined instruction is executed
Operating mode changes can be controlled by software. They can also be caused by external interrupts or
exception processing. Most application programs execute in user mode. Privileged modes (that is, all modes
other than User mode) are entered to service interrupts or exceptions, or to access protected resources.
1-19
PRODUCT OVERVIEW
S3C4510B
REGISTERS
The S3C4510B CPU core has a total of 37 registers: 31 general-purpose 32-bit registers, and 6 status registers.
Not all of these registers are always available. Whether a registers is available to the programmer at any given
time depends on the current processor operating state and mode.
NOTE
When the S3C4510B is operating in ARM state, 16 general registers and one or two status registers can
be accessed at any time. In privileged mode, mode-specific banked registers are switched in.
Two register sets, or banks, can also be accessed, depending on the core¢s current state, the ARM state register
set and the THUMB state register set:
·
The ARM state register set contains 16 directly accessible registers: R0-R15. All of these registers, except for
R15, are for general-purpose use, and can hold either data or address values. An additional (17th) register,
the CPSR (Current Program Status Register), is used to store status information.
·
The THUMB state register set is a subset of the ARM state set. You can access 8 general registers, R0-R7,
as well as the program counter (PC), a stack pointer register (SP), a link register (LR), and the CPSR. Each
privileged mode has a corresponding banked stack pointer, link register, and saved process status register
(SPSR).
The THUMB state registers are related to the ARM state registers as follows:
·
·
·
THUMB state R0-R7 registers and ARM state R0–R7 registers are identical
THUMB state CPSR and SPSRs and ARM state CPSR and SPSRs are identical
THUMB state SP, LR, and PC are mapped directly to ARM state registers R13, R14, and R15, respectively
In THUMB state, registers R8-R15 are not part of the standard register set. However, you can access them for
assembly language programming and use them for fast temporary storage, if necessary.
1-20
S3C4510B
PRODUCT OVERVIEW
EXCEPTIONS
An exception arises when the normal flow of program execution is interrupted, e.g., when processing is diverted
to handle an interrupt from a peripheral. The processor state just prior to handling the exception must be
preserved so that the program flow can be resumed when the exception routine is completed. Multiple exceptions
may arise simultaneously.
To process exceptions, the S3C4510B uses the banked core registers to save the current state. The old PC value
and the CPSR contents are copied into the appropriate R14 (LR) and SPSR registers. The PC and mode bits in
the CPSR are adjusted to the value corresponding to the type of exception being processed.
The S3C4510B core supports seven types of exceptions. Each exception has a fixed priority and a corresponding
privileged processor mode, as shown in Table 1-4.
Table 1-4. S3C4510B CPU Exceptions
Exception
Mode on Entry
Supervisor mode
Priority
Reset
1 (highest)
Data abort
Abort mode
2
FIQ
FIQ mode
3
IRQ
IRQ mode
4
Prefetch abort
Undefined instruction
SWI
Abort mode
5
6
Undefined mode
Supervisor mode
6 (lowest)
1-21
PRODUCT OVERVIEW
S3C4510B
SPECIAL REGISTERS
Table 1-5. S3C4510B Special Registers
R/W Description
Group
Registers
Offset
0x0000
0x3000
0x3008
0x300C
0x3010
0x3014
0x3018
0x301C
0x3020
0x3024
0x3028
0x302C
0x3030
0x3034
0x3038
0x303C
0x9000
0x9004
Reset/Value
0x37FFFF91
0x00000000
0x00000000
0x00000000
0x00000000
0x20000060
0x00000060
0x00000060
0x00000060
0x00000060
0x00000060
0x00000000
0x00000000
0x00000000
0x00000000
0x000083FD
0x00000000
0x00000000
System
SYSCFG
R/W System configuration register
Manager CLKCON
EXTACON0
EXTACON1
EXTDBWTH
ROMCON0
R/W Clock control register
R/W External I/O timing register 1
R/W External I/O timing register 2
R/W Data bus width for each memory bank
R/W ROM/SRAM/Flash bank 0 control register
R/W ROM/SRAM/Flash bank 1 control register
R/W ROM/SRAM/Flash bank 2 control register
R/W ROM/SRAM/Flash bank 3 control register
R/W ROM/SRAM/Flash bank 4 control register
R/W ROM/SRAM/Flash bank 5 control register
R/W DRAM bank 0 control register
ROMCON1
ROMCON2
ROMCON3
ROMCON4
ROMCON5
DRAMCON0
DRAMCON1
DRAMCON2
DRAMCON3
REFEXTCON
R/W DRAM bank 1 control register
R/W DRAM bank 2 control register
R/W DRAM bank 3 control register
R/W Refresh and external I/O control register
R/W Buffered DMA receive control register
R/W Buffered DMA transmit control register
Ethernet
(BDMA)
BDMATXCON
BDMARXCO
N
BDMATXPTR
BDMARXPTR
BDMARXLSZ
BDMASTAT
CAM
0x9008
0x900C
0x9010
0x9014
R/W Transmit frame descriptor start address
R/W Receive frame descriptor start address
R/W Receive frame maximum size
R/W Buffered DMA status
0x00000000
0x00000000
Undefined
0x00000000
Undefined
0x9100–
0x917C
W
CAM content (32 words)
BDMATXBUF
BDMARXBUF
0x9200–
0x92FC
R/W BDMA Tx buffer (64 words) for test mode
addressing
Undefined
Undefined
0x9800–
0x99FC
R/W BDMA Rx buffer (64 words) for test mode
addressing
1-22
S3C4510B
PRODUCT OVERVIEW
Table 1-5. S3C4510B Special Registers (Continued)
Group
Ethernet
(MAC)
Registers
MACON
Offset
0xA000
0xA004
0xA008
0xA00C
0xA010
0xA014
0xA018
0xA01C
0xA028
0xA03C
0xA040
0xA044
0x9040
0x7000
0x7004
0x7008
0x700C
0x7010
0x7014
0x7018
0x701C
0x7020
0x7024
0x7028
0x702C
0x7030
0x7034
0x7038
0x703C
0x7040
0x7040
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Description
Ethernet MAC control register
CAM control register
Reset/Value
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
CAMCON
MACTXCON
MACTXSTAT
MACRXCON
MACRXSTAT
STADATA
STACON
MAC transmit control register
MAC transmit status register
MAC receive control register
MAC receive status register
R/W Station management data
R/W Station management control and address
R/W CAM enable register
0x00006000
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
0x00010400
0x00000000
–
CAMEN
EMISSCNT
EPZCNT
R/W Missed error count register
R
R
R
Pause count register
ERMPZCNT
ETXSTAT
HMODE
Remote pause count register
Transmit control frame status
HDLC
R/W HDLC mode register
Channel A HCON
HSTAT
R/W HDLC control register
R/W HDLC status register
R/W HDLC interrupt enable register
HINTEN
HTXFIFOC
W
W
R
TxFIFO frame continue register
TxFIFO frame terminate register
HDLC RxFIFO entry register
HTXFIFOT
HRXFIFO
HBRGTC
HPRMB
–
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
0xFFFFFFFF
0xFFFFFFFF
0xXXXX0000
0xXXXX0000
R/W HDLC baud rate generate time constant
R/W HDLC preamble constant
R/W HDLC station address 0
HSAR0
HSAR1
R/W HDLC station address 1
HSAR2
R/W HDLC station address 2
HSAR3
R/W HDLC station address 3
HMASK
R/W HDLC mask register
DMATxPTR
DMARxPTR
HMFLR
R/W DMA Tx buffer descriptor pointer
R/W DMA Rx buffer descriptor pointer
R/W Maximum frame length register
R/W DMA receive buffer size register
HRBSR
1-23
PRODUCT OVERVIEW
S3C4510B
Table 1-5. S3C4510B Special Registers (Continued)
R/W Description
Group
HDLC
Registers
HMODE
Offset
0x8000
0x8004
0x8008
0x800C
0x8010
0x8014
0x8018
0x801C
0xA020
0x8024
0x8028
0x802C
0x8030
0x8034
0x8038
0x803C
0x8040
0x8044
0x5000
0x5004
0x5008
0x4000
0x4004
0x4008
0x400C
0x4010
0x4014
0x4018
0x401C
0x4020
0x4024
0x4030
0x4034
0XF000
0xF004
0xF008
0xF00C
Reset/Value
0x00000000
0x00000000
0x00010400
0x00000000
–
R/W HDLC mode register
Channel B HCON
HSTAT
R/W HDLC control register
R/W HDLC status register
R/W HDLC interrupt enable register
HINTEN
HTXFIFOC
W
W
R
TxFIFO frame continue register
TxFIFO frame terminate register
HDLC RxFIFO entry register
HTXFIFOT
HRXFIFO
HBRGTC
HPRMB
–
0x00000000
0x00000000
0x00000000
0x00006000
0x00000000
0x00000000
0x00000000
0x00000000
0xFFFFFFFF
0xFFFFFFFF
0xXXXX0000
0xXXXX0000
0x00000000
0x00000000
Undefined
R/W HDLC baud rate generate time constant
R/W HDLC preamble constant
R/W HDLC station address 0
HSAR0
HSAR1
R/W HDLC station address 1
HSAR2
R/W HDLC station address 2
HSAR3
R
R
R
HDLC station address 3
HDLC mask register
HMASK
DMATxPTR
DMARxPTR
HMFLR
DMA Tx buffer descriptor pointer
R/W DMA Rx buffer descriptor pointer
R/W Maximum frame length register
R/W DMA receive buffer size register
R/W I/O port mode register
HRBSR
I/O Ports
IOPMOD
IOPCON
IOPDATA
INTMOD
INTPND
R/W I/O port control register
R/W Input port data register
Interrupt
R/W Interrupt mode register
0x00000000
0x00000000
0x003FFFFF
0x03020100
0x07060504
0x0B0A0908
0x0F0E0D0C
0x13121110
0x00000014
0x00000054
0x00000054
0x00000054
0x00000054
Undefined
Controller
R/W Interrupt pending register
R/W Interrupt mask register
INTMSK
INTPRI0
INTPRI1
INTPRI2
INTPRI3
INTPRI4
INTPRI5
INTOFFSET
INTOSET_FIQ
INTOSET_IRQ
IICCON
R/W Interrupt priority register 0
R/W Interrupt priority register 1
R/W Interrupt priority register 2
R/W Interrupt priority register 3
R/W Interrupt priority register 4
R/W Interrupt priority register 5
R
R
R
Interrupt offset address register
FIQ interrupt offset register
IRQ interrupt offset register
I2C Bus
R/W I2C bus control status register
R/W I2C bus shift buffer register
R/W I2C bus prescaler register
IICBUF
IICPS
0x00000000
0x00000000
IICCOUNT
R
I2C bus prescaler counter register
1-24
S3C4510B
PRODUCT OVERVIEW
Table 1-5. S3C4510BC Special Registers (Continued)
R/W Description
Group
Registers
GDMACON0
GDMACON1
GDMASRC0
GDMADST0
GDMASRC1
GDMADST1
GDMACNT0
GDMACNT1
ULCON0
Offset
0xB000
0xC000
0xB004
0xB008
0xC004
0xC008
0xB00C
0xC00C
0xD000
0xE000
0xD004
0xE004
0xD008
0xE008
0xD00C
0xE00C
0xD010
0xE010
0xD014
0xE014
0x6000
0x6004
0x6008
0x600C
0x6010
Reset/Value
0x00000000
0x00000000
Undefined
Undefined
Undefined
Undefined
GDMA
R/W GDMA channel 0 control register
R/W GDMA channel 1 control register
R/W GDMA source address register 0
R/W GDMA destination address register 0
R/W GDMA source address register 1
R/W GDMA destination address register 1
R/W GDMA channel 0 transfer count register
R/W GDMA channel 1 transfer count register
R/W UART channel 0 line control register
R/W UART channel 1 line control register
R/W UART channel 0 control register
Undefined
Undefined
0x00
UART
ULCON1
0x00
UCON0
0x00
UCON1
R/W UART channel 1 control register
0x00
USTAT0
R
R
UART channel 0 status register
0xC0
USTAT1
UART channel 1 status register
0xC0
UTXBUF0
UTXBUF1
URXBUF0
URXBUF1
UBRDIV0
UBRDIV1
TMOD
W
W
R
UART channel 0 transmit holding register
UART channel 1 transmit holding register
UART channel 0 receive buffer register
UART channel 1 receive buffer register
Undefined
Undefined
Undefined
Undefined
0x00
R
R/W Baud rate divisor register 0
R/W Baud rate divisor register 1
R/W Timer mode register
R/W Timer 0 data register
R/W Timer 1 data register
R/W Timer 0 count register
R/W Timer 1 count register
0x00
Timers
0x00000000
0x00000000
0x00000000
0xFFFFFFFF
0xFFFFFFFF
TDATA0
TDATA1
TCNT0
TCNT1
1-25
PRODUCT OVERVIEW
S3C4510B
NOTES
1-26
S3C4510B
PROGRAMMER'S MODEL
2
PROGRAMMER¢S MODEL
OVERVIEW
S3C4510B was developed using the advanced ARM7TDMI core designed by advanced RISC machines, Ltd.
Processor Operating States
From the programmer¢s point of view, the ARM7TDMI can be in one of two states:
— ARM state which executes 32-bit, word-aligned ARM instructions.
— THUMB state which operates with 16-bit, half-word-aligned THUMB instructions. In this state, the PC uses bit
1 to select between alternate half-words.
NOTE
Transition between these two states does not affect the processor mode or the contents of the registers.
SWITCHING STATE
Entering THUMB State
Entry into THUMB state can be achieved by executing a BX instruction with the state bit (bit 0) set in the operand
register.
Transition to THUMB state will also occur automatically on return from an exception (IRQ, FIQ, UNDEF, ABORT,
SWI etc.), if the exception was entered with the processor in THUMB state.
Entering ARM State
Entry into ARM state happens:
1. On execution of the BX instruction with the state bit clear in the operand register.
2. On the processor taking an exception (IRQ, FIQ, RESET, UNDEF, ABORT, SWI etc.). In this case, the PC is
placed in the exception mode¢s link register, and execution commences at the exception¢s vector address.
MEMORY FORMATS
ARM7TDMI views memory as a linear collection of bytes numbered upwards from zero. Bytes 0 to 3 hold the first
stored word, bytes 4 to 7 the second and so on. ARM7TDMI can treat words in memory as being stored either in
Big-Endian or Little-Endian format.
2-1
PROGRAMMER'S MODEL
BIG-ENDIAN FORMAT
S3C4510B
In Big-Endian format, the most significant byte of a word is stored at the lowest numbered byte and the least
significant byte at the highest numbered byte. Byte 0 of the memory system is therefore connected to data lines
31 through 24.
Higher address 31
24
9
5
15
8
7
0
Word address
8
4
0
9
5
1
10
6
11
7
8
4
0
2
3
Lower address
w
w
Most significant byte is at lowest address
Word is addressed by byte address of most signficant byte
Figure 2-1. Big-Endian Addresses of Bytes within Words
NOTE
The data locations in the external memory are different with Figure 2-1 in the S3C4620. Please refer to
the chapter 4, system manager.
LITTLE-ENDIAN FORMAT
In Little-Endian format, the lowest numbered byte in a word is considered the word¢s least significant byte, and
the highest numbered byte the most significant. Byte 0 of the memory system is therefore connected to data lines
7 through 0.
Word address
Higher address 31
24
23
16
15
8
7
0
11
7
10
6
9
5
1
8
4
0
8
4
0
3
2
Lower address
w
w
Most significant byte is at lowest address
Word is addressed by byte address of least signficant byte
Figure 2-2. Little-Endian Addresses of Bytes Words
2-2
S3C4510B
PROGRAMMER'S MODEL
INSTRUCTION LENGTH
Instructions are either 32 bits long (in ARM state) or 16 bits long (in THUMB state).
Data Types
ARM7TDMI supports byte (8-bit), half-word (16-bit) and word (32-bit) data types. Words must be aligned to four-
byte boundaries and half words to two-byte boundaries.
OPERATING MODES
ARM7TDMI supports seven modes of operation:
— User (usr):
— FIQ (fiq):
— IRQ (irq):
The normal ARM program execution state
Designed to support a data transfer or channel process
Used for general-purpose interrupt handling
— Supervisor (svc): Protected mode for the operating system
— Abort mode (abt): Entered after a data or instruction prefetch abort
— System (sys):
A privileged user mode for the operating system
— Undefined (und): Entered when an undefined instruction is executed
Mode changes may be made under software control, or may be brought about by external interrupts or exception
processing. Most application programs will execute in User mode. The non-user modes known as privileged
modes-are entered in order to service interrupts or exceptions, or to access protected resources.
2-3
PROGRAMMER'S MODEL
REGISTERS
S3C4510B
ARM7TDMI has a total of 37 registers-31 general-purpose 32-bit registers and six status registers - but these
cannot all be seen at once. The processor state and operating mode dictate which registers are available to the
programmer.
The ARM State Register Set
In ARM state, 16 general registers and one or two status registers are visible at any one time. In privileged (non-
User) modes, mode-specific banked registers are switched in. Figure 2-3 shows which registers are available in
each mode: the banked registers are marked with a shaded triangle.
The ARM state register set contains 16 directly accessible registers: R0 to R15. All of these except R15 are
general-purpose, and may be used to hold either data or address values. In addition to these, there is a
seventeenth register used to store status information.
Register 14
is used as the subroutine link register. This receives a copy of R15 when a branch
and link (BL) instruction is executed. At all other times it may be treated as a
general-purpose register. The corresponding banked registers R14_svc, R14_irq,
R14_fiq, R14_abt and R14_und are similarly used to hold the return values of
R15 when interrupts and exceptions arise, or when branch and link instructions are
executed within interrupt or exception routines.
Register 15
Register 16
holds the Program Counter (PC). In ARM state, bits [1:0] of R15 are zero and bits
[31:2] contain the PC. In THUMB state, bit [0] is zero and bits [31:1] contain the PC.
is the CPSR (Current Program Status Register). This contains condition code flags
and the current mode bits.
FIQ mode has seven banked registers mapped to R8-14 (R8_fiq-R14_fiq). In ARM state, many FIQ handlers do
not need to save any registers. User, IRQ, Supervisor, Abort and Undefined each have two banked registers
mapped to R13 and R14, allowing each of these modes to have a private stack pointer and link registers.
2-4
S3C4510B
PROGRAMMER'S MODEL
ARM State General Registers and Program Counter
System & User
FIQ
Supervisor
About
R0
IRG
R0
Undefined
R0
R1
R2
R3
R4
R5
R6
R7
R0
R0
R0
R1
R1
R1
R1
R1
R2
R2
R2
R2
R2
R3
R3
R3
R3
R3
R4
R4
R4
R4
R4
R5
R5
R5
R5
R5
R6
R6
R6
R6
R6
R7
R7
R7
R7
R7
R8
R8
R8
R8
R8_fiq
R8
R9
R9
R9
R9
R9_fiq
R9
R10
R11
R12
R13_svc
R14_svc
R15 (PC)
R10
R11
R12
R13_abt
R14_abt
R15 (PC)
R10
R11
R12
R13_irq
R14_irq
R15 (PC)
R10
R11
R12
R13_und
R14_und
R15 (PC)
R10_fiq
R11_fiq
R12_fiq
R13_fiq
R14_fiq
R15 (PC)
R10
R11
R12
R13
R14
R15 (PC)
ARM State Program Status Register
CPSR
CPSR
CPSR
CPSR
CPSR
CPSR
SPSR_fiq
SPSR_svc
SPSR_abt
SPSR_irq
SPSR_und
= banked register
Figure 2-3. Register Organization in ARM State
2-5
PROGRAMMER'S MODEL
S3C4510B
The THUMB State Register Set
The THUMB state register set is a subset of the ARM state set. The programmer has direct access to eight
general registers, R0–R7, as well as the Program Counter (PC), a stack pointer register (SP), a link register (LR),
and the CPSR. There are banked stack pointers, link registers and Saved Process Status Registers (SPSRs) for
each privileged mode. This is shown in Figure 2-4.
THUMB State General Registers and Program Counter
System & User
FIQ
R0
Supervisor
About
IRG
R0
Undefined
R0
R1
R2
R3
R4
R5
R6
R7
SP
LR
PC
R0
R0
R0
R1
R1
R1
R1
R1
R2
R2
R2
R2
R2
R3
R3
R3
R3
R3
R4
R4
R4
R4
R4
R5
R5
R5
R5
R5
R6
R6
R6
R6
R6
R7
R7
R7
R7
R7
SP_fiq
LR_fiq
PC
SP_svg
LR_svc
PC
SP_abt
LR_abt
PC
SP_irq
LR_irq
PC
SP_und
LR_und
PC
THUMB State Program Status Registers
CPSR
CPSR
CPSR
CPSR
CPSR
CPSR
SPSR_fiq
SPSR_svc
SPSR_abt
SPSR_irq
SPSR_und
= banked register
Figure 2-4. Register Organization in THUMB State
2-6
S3C4510B
PROGRAMMER'S MODEL
The Relationship between ARM and THUMB State Registers
The THUMB state registers relate to the ARM state registers in the following way:
— THUMB state R0–R7 and ARM state R0–R7 are identical
— THUMB state CPSR and SPSRs and ARM state CPSR and SPSRs are identical
— THUMB state SP maps onto ARM state R13
— THUMB state LR maps onto ARM state R14
— The THUMB state program counter maps onto the ARM state program counter (R15)
This relationship is shown in Figure 2-5.
THUMB State
ARM State
R0
R1
R2
R3
R4
R5
R6
R7
R0
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10
R11
R12
Stack Pointer (SP)
Link Register (LR)
Program Counter (PC)
CPSR
Stack Pointer (R13)
Link Register (R14)
Program Counter (R15)
CPSR
SPSR
SPSR
Figure 2-5. Mapping of THUMB State Registers onto ARM State Registers
2-7
PROGRAMMER'S MODEL
S3C4510B
Accessing Hi-Registers in THUMB State
In THUMB state, registers R8–R15 (the Hi registers) are not part of the standard register set. However, the
assembly language programmer has limited access to them, and can use them for fast temporary storage.
A value may be transferred from a register in the range R0–R7 (a Lo register) to a Hi register, and from a Hi
register to a Lo register, using special variants of the MOV instruction. Hi register values can also be compared
against or added to Lo register values with the CMP and ADD instructions. For more information, refer to Figure
3-34.
THE PROGRAM STATUS REGISTERS
The ARM7TDMI contains a Current Program Status Register (CPSR), plus five Saved Program Status Registers
(SPSRs) for use by exception handlers. These register¢s functions are:
— Hold information about the most recently performed ALU operation
— Control the enabling and disabling of interrupts
— Set the processor operating mode
The arrangement of bits is shown in Figure 2-6.
Control Bits
Condition Code Flags
(Reserved)
31
30
29
28
27
26
25
24
8
7
6
5
4
3
2
1
0
N
Z
C
V
.
.
.
.
.
.
I
F
T
M4
M3
M2
M1
M0
Overflow
Mode bits
State bit
Carry/Borrow/Extend
Zero
FIQ disable
IRQ disable
Negative/Less Than
Figure 2-6. Program Status Register Format
2-8
S3C4510B
PROGRAMMER'S MODEL
The Condition Code Flags
The N, Z, C and V bits are the condition code flags. These may be changed as a result of arithmetic and logical
operations, and may be tested to determine whether an instruction should be executed.
In ARM state, all instructions may be executed conditionally: see Table 3-2 for details.
In THUMB state, only the branch instruction is capable of conditional execution: see Figure 3-46 for details.
The Control Bits
The bottom 8 bits of a PSR (incorporating I, F, T and M[4:0]) are known collectively as the control bits. These will
change when an exception arises. If the processor is operating in a privileged mode, they can also be
manipulated by software.
The T bit
This reflects the operating state. When this bit is set, the processor is executing in
THUMB state, otherwise it is executing in ARM state. This is reflected on the TBIT
external signal.
Note that the software must never change the state of the TBIT in the CPSR. If this
happens, the processor will enter an unpredictable state.
Interrupt disable bits
The mode bits
The I and F bits are the interrupt disable bits. When set, these disable the IRQ and
FIQ interrupts respectively.
The M4, M3, M2, M1 and M0 bits (M[4:0]) are the mode bits. These determine the
processor¢s operating mode, as shown in Table 2-1. Not all combinations of the
mode bits define a valid processor mode. Only those explicitly described shall be
used. The user should be aware that if any illegal value is programmed into the
mode bits, M[4:0], then the processor will enter an unrecoverable state. If this
occurs, reset should be applied.
2-9
PROGRAMMER'S MODEL
S3C4510B
Table 2-1. PSR Mode. Bit Values
Visible THUMB State Registers
M[4:0]
10000
Mode
User
Visible ARM State Registers
R14..R0,
R7..R0,
LR, SP
PC, CPSR
PC, CPSR
10001
10010
10011
10111
11011
11111
FIQ
R7..R0,
R7..R0,
LR_fiq, SP_fiq
PC, CPSR, SPSR_fiq
R7..R0,
R14_fiq..R8_fiq,
PC, CPSR, SPSR_fiq
R12..R0,
IRQ
LR_irq, SP_irq
PC, CPSR, SPSR_irq
R7..R0,
R14_irq..R13_irq,
PC, CPSR, SPSR_irq
R12..R0,
Supervisor
Abort
LR_svc, SP_svc,
PC, CPSR, SPSR_svc
R7..R0,
R14_svc..R13_svc,
PC, CPSR, SPSR_svc
R12..R0,
LR_abt, SP_abt,
PC, CPSR, SPSR_abt
R7..R0
R14_abt..R13_abt,
PC, CPSR, SPSR_abt
R12..R0,
Undefined
System
LR_und, SP_und,
PC, CPSR, SPSR_und
R7..R0,
R14_und..R13_und,
PC, CPSR
R14..R0,
LR, SP
PC, CPSR
PC, CPSR
Reserved bits
The remaining bits in the PSRs are reserved. When changing a PSR¢s flag or
control bits, you must ensure that these unused bits are not altered. Also, your
program should not rely on them containing specific values, since in future
processors they may read as one or zero.
2-10
S3C4510B
PROGRAMMER'S MODEL
EXCEPTIONS
Exceptions arise whenever the normal flow of a program has to be halted temporarily, for example to service an
interrupt from a peripheral. Before an exception can be handled, the current processor state must be preserved
so that the original program can resume when the handler routine has finished.
It is possible for several exceptions to arise at the same time. If this happens, they are dealt with in a fixed order.
See Exception Priorities on page 2-14.
Action on Entering an Exception
When handling an exception, the ARM7TDMI:
1. Preserves the address of the next instruction in the appropriate Link Register. If the exception has been
entered from ARM state, then the address of the next instruction is copied into the Link Register (that is,
current PC + 4 or PC + 8 depending on the exception. See Table 2-2 on for details). If the exception has
been entered from THUMB state, then the value written into the Link Register is the current PC offset by a
value such that the program resumes from the correct place on return from the exception. This means that
the exception handler need not determine which state the exception was entered from. For example, in the
case of SWI, MOVS PC, R14_svc will always return to the next instruction regardless of whether the SWI
was executed in ARM or THUMB state.
2. Copies the CPSR into the appropriate SPSR
3. Forces the CPSR mode bits to a value which depends on the exception
4. Forces the PC to fetch the next instruction from the relevant exception vector
It may also set the interrupt disable flags to prevent otherwise unmanageable nesting of exceptions.
If the processor is in THUMB state when an exception occurs, it will automatically switch into ARM state when the
PC is loaded with the exception vector address.
Action on Leaving an Exception
On completion, the exception handler:
1. Moves the Link Register, minus an offset where appropriate, to the PC. (The offset will vary depending on the
type of exception.)
2. Copies the SPSR back to the CPSR
3. Clears the interrupt disable flags, if they were set on entry
NOTE
An explicit switch back to THUMB state is never needed, since restoring the CPSR from the SPSR
automatically sets the T bit to the value it held immediately prior to the exception.
2-11
PROGRAMMER'S MODEL
S3C4510B
Exception Entry/Exit Summary
Table 2-2 summarizes the PC value preserved in the relevant R14 on exception entry, and the recommended
instruction for exiting the exception handler.
Table 2-2. Exception Entry/Exit
Return Instruction
Previous State
ARM R14_x
Notes
THUMB R14_x
PC + 2
PC + 2
PC + 2
PC + 4
PC + 4
PC + 4
PC + 8
–
BL
MOV PC, R14
PC + 4
PC + 4
PC + 4
PC + 4
PC + 4
PC + 4
PC + 8
–
1
1
1
2
2
1
3
4
SWI
MOVS PC, R14_svc
MOVS PC, R14_und
SUBS PC, R14_fiq, #4
SUBS PC, R14_irq, #4
SUBS PC, R14_abt, #4
SUBS PC, R14_abt, #8
NA
UDEF
FIQ
IRQ
PABT
DABT
RESET
NOTES:
1. Where PC is the address of the BL/SWI/Undefined Instruction fetch which had the prefetch abort.
2. Where PC is the address of the instruction which did not get executed since the FIQ or IRQ took priority.
3. Where PC is the address of the Load or Store instruction which generated the data abort.
4. The value saved in R14_svc upon reset is unpredictable.
FIQ
The FIQ (Fast Interrupt Request) exception is designed to support a data transfer or channel process, and in
ARM state has sufficient private registers to remove the need for register saving (thus minimizing the overhead
of context switching).
FIQ is externally generated by taking the nFIQ input LOW. This input can except either synchronous or
asynchronous transitions, depending on the state of the ISYNC input signal. When ISYNC is LOW, nFIQ and
nIRQ are considered asynchronous, and a cycle delay for synchronization is incurred before the interrupt can
affect the processor flow.
Irrespective of whether the exception was entered from ARM or Thumb state, a FIQ handler should leave the
interrupt by executing
SUBS
PC,R14_fiq,#4
FIQ may be disabled by setting the CPSR's F flag (but note that this is not possible from User mode). If the F flag
is clear, ARM7TDMI checks for a LOW level on the output of the FIQ synchroniser at the end of each instruction.
2-12
S3C4510B
IRQ
PROGRAMMER'S MODEL
The IRQ (Interrupt Request) exception is a normal interrupt caused by a LOW level on the nIRQ input. IRQ has a
lower priority than FIQ and is masked out when a FIQ sequence is entered. It may be disabled at any time by
setting the I bit in the CPSR, though this can only be done from a privileged (non-User) mode.
Irrespective of whether the exception was entered from ARM or Thumb state, an IRQ handler should return from
the interrupt by executing
SUBS
PC,R14_irq,#4
Abort
An abort indicates that the current memory access cannot be completed. It can be signalled by the external
ABORT input. ARM7TDMI checks for the abort exception during memory access cycles.
There are two types of abort:
—
Prefetch abort: occurs during an instruction prefetch.
— Data abort: occurs during a data access.
If a prefetch abort occurs, the prefetched instruction is marked as invalid, but the exception will not be taken until
the instruction reaches the head of the pipeline. If the instruction is not executed - for example because a branch
occurs while it is in the pipeline - the abort does not take place.
If a data abort occurs, the action taken depends on the instruction type:
—
Single data transfer instructions (LDR, STR) write back modified base registers: the Abort handler must be
aware of this.
—
—
The swap instruction (SWP) is aborted as though it had not been executed.
Block data transfer instructions (LDM, STM) complete. If write-back is set, the base is updated. If the
instruction would have overwritten the base with data (ie it has the base in the transfer list), the overwriting is
prevented. All register overwriting is prevented after an abort is indicated, which means in particular that R15
(always the last register to be transferred) is preserved in an aborted LDM instruction.
The abort mechanism allows the implementation of a demand paged virtual memory system. In such a system
the processor is allowed to generate arbitrary addresses. When the data at an address is unavailable, the
Memory Management Unit (MMU) signals an abort. The abort handler must then work out the cause of the abort,
make the requested data available, and retry the aborted instruction. The application program needs no
knowledge of the amount of memory available to it, nor is its state in any way affected by the abort.
After fixing the reason for the abort, the handler should execute the following irrespective of the state (ARM or
Thumb):
SUBS
SUBS
PC,R14_abt,#4
PC,R14_abt,#8
; for a prefetch abort, or
; for a data abort
This restores both the PC and the CPSR, and retries the aborted instruction.
2-13
PROGRAMMER'S MODEL
Software Interrupt
S3C4510B
The software interrupt instruction (SWI) is used for entering Supervisor mode, usually to request a particular
supervisor function. A SWI handler should return by executing the following irrespective of the state (ARM or
Thumb):
MOV
PC,R14_svc
This restores the PC and CPSR, and returns to the instruction following the SWI.
NOTE
nFIQ, nIRQ, ISYNC, LOCK, BIGEND, and ABORT pins exist only in the ARM7TDMI CPU core.
Undefined Instruction
When ARM7TDMI comes across an instruction which it cannot handle, it takes the undefined instruction trap.
This mechanism may be used to extend either the THUMB or ARM instruction set by software emulation.
After emulating the failed instruction, the trap handler should execute the following irrespective of the state (ARM
or Thumb):
MOVS
PC,R14_und
This restores the CPSR and returns to the instruction following the undefined instruction.
Exception Vectors
The following table shows the exception vector addresses.
Table 2-3. Exception Vectors
Address
Exception
Mode in Entry
Supervisor
0x00000000
0x00000004
0x00000008
0x0000000C
0x00000010
0x00000014
0x00000018
0x0000001C
Reset
Undefined instruction
Software Interrupt
Abort (prefetch)
Abort (data)
Reserved
Undefined
Supervisor
Abort
Abort
Reserved
IRQ
IRQ
FIQ
FIQ
2-14
S3C4510B
PROGRAMMER¢S MODEL
Exception Priorities
When multiple exceptions arise at the same time, a fixed priority system determines the order in which they are
handled:
Highest priority:
1. Reset
2. Data abort
3. FIQ
4. IRQ
5. Prefetch abort
Lowest priority:
6. Undefined Instruction, Software interrupt.
Not All Exceptions Can Occur at Once:
Undefined Instruction and Software Interrupt are mutually exclusive, since they each correspond to particular
(non-overlapping) decoding of the current instruction.
If a data abort occurs at the same time as a FIQ, and FIQs are enabled (ie the CPSR's F flag is clear),
ARM7TDMI enters the data abort handler and then immediately proceeds to the FIQ vector. A normal return from
FIQ will cause the data abort handler to resume execution. Placing data abort at a higher priority than FIQ is
necessary to ensure that the transfer error does not escape detection. The time for this exception entry should be
added to worst-case FIQ latency calculations.
2-15
PROGRAMMER¢S MODEL
S3C4510B
Interrupt Latencies
The worst case latency for FIQ, assuming that it is enabled, consists of the longest time the request can take to
pass through the synchroniser (Tsyncmax if asynchronous), plus the time for the longest instruction to complete
(Tldm, the longest instruction is an LDM which loads all the registers including the PC), plus the time for the data
abort entry (Texc), plus the time for FIQ entry (Tfiq). At the end of this time ARM7TDMI will be executing the
instruction at 0x1C.
Tsyncmax is 3 processor cycles, Tldm is 20 cycles, Texc is 3 cycles, and Tfiq is 2 cycles. The total time is
therefore 28 processor cycles. This is just over 1.4 microseconds in a system which uses a continuous 20 MHz
processor clock. The maximum IRQ latency calculation is similar, but must allow for the fact that FIQ has higher
priority and could delay entry into the IRQ handling routine for an arbitrary length of time. The minimum latency
for FIQ or IRQ consists of the shortest time the request can take through the synchroniser (Tsyncmin) plus Tfiq.
This is 4 processor cycles.
Reset
When the nRESET signal goes LOW, ARM7TDMI abandons the executing instruction and then continues to fetch
instructions from incrementing word addresses.
When nRESET goes HIGH again, ARM7TDMI:
1. Overwrites R14_svc and SPSR_svc by copying the current values of the PC and CPSR into them. The value
of the saved PC and SPSR is not defined.
2. Forces M[4:0] to 10011 (Supervisor mode), sets the I and F bits in the CPSR, and clears the CPSR's T bit.
3. Forces the PC to fetch the next instruction from address 0x00.
4. Execution resumes in ARM state.
2-16
S3C4510B
INSTRUCTION SET
3
INSTRUCTION SET
INSTRUCTION SET SUMMAY
This chapter describes the ARM instruction set and the THUMB instruction set in the ARM7TDMI core.
FORMAT SUMMARY
The ARM instruction set formats are shown below.
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2 1 0
Data processing/
PSR Transfer
Cond
Cond
Cond
Cond
Cond
Cond
Cond
Cond
Cond
Cond
Cond
Cond
Cond
Cond
Cond
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
0
0
0
0
0
0
0
1
1
0
0
1
1
1
1
1
0
0
0
0
0
0
1
1
0
1
0
1
1
1
Opcode
S
S
S
0
Rn
Rd
Rd
Rn
Operand2
0
0
0
1
0
U
B
0
A
A
0
1
Rs
Rn
1
1
1
0
1
1
0
0
0
0
S
S
0
0
1
1
1
1
1
1
Rm
Multiply
RdHi
Rn
RnLo
Rd
Rm
Rm
Multiply Long
1
0
0
1
0
0
0
1
0
0
1
0
0
Single data swap
Branch and exchange
1
0
0
1
1
1
1
1
1
1
1
1
0
0
Rn
Halfword data transfer:
register offset
Halfword data transfer:
immediate offset
P
P
P
U
U
U
0
W L
W L
W L
Rn
Rd
H
H
Rm
1
Rn
Rn
Rd
Rd
Offset
Offset
B
Offset
Single data transfer
Undefined
1
P
L
P
0
0
1
U
S
W L
W L
Rn
Register List
Block data transfer
Branch
Offset
Coprocessor data
transfer
Coprocessor data
Operation
U
N
Rn
CRd
CRd
Rd
CP#
Offset
CP Opc
CP Opc
CRn
CRn
CP#
CP#
CP#
CP#
0
1
CRm
CRm
Coprocessor register
Transfer
L
Ignored by processor
Software Interrupt
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2 1 0
Figure 3-1. ARM Instruction Set Format
NOTE
Some instruction codes are not defined but do not cause the Undefined instruction trap to be taken, for
instance a Multiply instruction with bit 6 changed to a 1. These instructions should not be used, as their
action may change in future ARM implementations.
3-1
INSTRUCTION SET
S3C4510B
INSTRUCTION SUMMARY
Table 3-1. The ARM Instruction Set
Instruction
Mnemonic
Action
ADC
ADD
AND
B
Add with carry
Rd: = Rn + Op2 + Carry
Rd: = Rn + Op2
Add
AND
Rd: = Rn AND Op2
R15: = address
Branch
BIC
BL
Bit clear
Rd: = Rn AND NOT Op2
R14: = R15, R15: = address
R15: = Rn,
Branch with link
Branch and exchange
BX
T bit: = Rn[0]
CDP
CMN
CMP
EOR
Coprocessor data processing
Compare negative
Compare
(coprocessor-specific)
CPSR flags: = Rn + Op2
CPSR flags: = Rn - Op2
Rd: = (Rn AND NOT Op2)
OR (op2 AND NOT Rn)
Coprocessor load
Exclusive OR
LDC
LDM
LDR
MCR
MLA
MOV
MRC
MRS
MSR
MUL
MVN
Load coprocessor from memory
Load multiple registers
Stack manipulation (Pop)
Rd: = (address)
Load register from memory
Move CPU register to coprocessor register
Multiply accumulate
cRn: = rRn {<op>cRm}
Rd: = (Rm * Rs) + Rn
Rd: = Op2
Move register or constant
Move from coprocessor register to CPU register Rn: = cRn {<op>cRm}
Move PSR status/flags to register
Move register to PSR status/flags
Multiply
Rn: = PSR
PSR: = Rm
Rd: = Rm * Rs
Move negative register
Rd: = 0xFFFFFFFF EOR Op2
3-2
S3C4510B
INSTRUCTION SET
Table 3-1. The ARM Instruction Set (Continued)
Instruction
Mnemonic
Action
ORR
RSB
RSC
SBC
STC
STM
STR
SUB
SWI
SWP
TEQ
TST
OR
Rd: = Rn OR Op2
Rd: = Op2 - Rn
Reverse subtract
Reverse subtract with carry
Subtract with carry
Store coprocessor register to memory
Store multiple
Rd: = Op2 - Rn-1 + Carry
Rd: = Rn - Op2-1 + Carry
Address: = CRn
Stack manipulation (push)
<address>: = Rd
Store register to memory
Subtract
Rd: = Rn - Op2
Software Interrupt
OS call
Swap register with memory
Test bit-wise equality
Test bits
Rd: = [Rn], [Rn] := Rm
CPSR flags: = Rn EOR Op2
CPSR flags: = Rn AND Op2
3-3
INSTRUCTION SET
S3C4510B
THE CONDITION FIELD
In ARM state, all instructions are conditionally executed according to the state of the CPSR condition codes and
the instruction¢s condition field. This field (bits 31:28) determines the circumstances under which an instruction is
to be executed. If the state of the C, N, Z and V flags fulfils the conditions encoded by the field, the instruction is
executed, otherwise it is ignored.
There are sixteen possible conditions, each represented by a two-character suffix that can be appended to the
instruction¢s mnemonic. For example, a branch (B in assembly language) becomes BEQ for "Branch if "Equal",
which means the branch will only be taken if the Z flag is set.
In practice, fifteen different conditions may be used: these are listed in Table 3-2. The sixteenth (1111) is
reserved, and must not be used.
In the absence of a suffix, the condition field of most instructions is set to “Always" (suffix AL). This means the
instruction will always be executed regardless of the CPSR condition codes.
Table 3-2. Condition Code Summary
Code
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
Suffix
EQ
NE
CS
CC
MI
Flags
Meaning
Z set
Equal
Z clear
C set
Not equal
Unsigned higher or same
Unsigned lower
Negative
C clear
N set
PL
N clear
V set
Positive or zero
Overflow
VS
VC
HI
V clear
No overflow
C set and Z clear
C clear or Z set
Unsigned higher
Unsigned lower or same
Greater or equal
Less than
LS
GE
LT
N equals V
N not equal to V
Z clear AND (N equals V)
Z set OR (N not equal to V)
(Ignored)
GT
LE
Greater than
Less than or equal
Always
AL
3-4
S3C4510B
INSTRUCTION SET
BRANCH AND EXCHANGE (BX)
This instruction is only executed if the condition is true. The various conditions are defined in Table 3-2.
This instruction performs a branch by copying the contents of a general register, Rn, into the program counter,
PC. The branch causes a pipeline flush and refill from the address specified by Rn. This instruction also permits
the instruction set to be exchanged. When the instruction is executed, the value of Rn[0] determines whether the
instruction stream will be decoded as ARM or THUMB instructions.
31
28 27
24 23
20 19
16 15
12 11
8 7
4 3
0
0
0
0
1
0
0
1
0
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
1
Cond
Rn
[3:0] Operand Register
If bit0 of Rn = 1, subsequent instructions decoded as THUMB instructions
If bit0 of Rn =0, subsequent instructions decoded as ARM instructions
[31:28] Condition Field
Figure 3-2. Branch and Exchange Instructions
INSTRUCTION CYCLE TIMES
The BX instruction takes 2S + 1N cycles to execute, where S and N are defined as sequential (S-cycle) and non-
sequential (N-cycle), respectively.
ASSEMBLER SYNTAX
BX - branch and exchange.
BX {cond} Rn
{cond}
Rn
Two character condition mnemonic. See Table 3-2.
is an expression evaluating to a valid register number.
USING R15 AS AN OPERAND
If R15 is used as an operand, the behaviour is undefined.
3-5
INSTRUCTION SET
S3C4510B
Examples
ADR
R0, Into_THUMB + 1
R0
; Generate branch target address
; and set bit 0 high - hence
; arrive in THUMB state.
; Branch and change to THUMB
; state.
BX
CODE16
Into_THUMB
; Assemble subsequent code as
; THUMB instructions
·
·
·
ADR R5, Back_to_ARM
; Generate branch target to word aligned address
; - hence bit 0 is low and so change back to ARM state.
; Branch and change back to ARM state.
BX R5
·
·
·
ALIGN
; Word align
CODE32
Back_to_ARM
; Assemble subsequent code as ARM instructions
3-6
S3C4510B
INSTRUCTION SET
BRANCH AND BRANCH WITH LINK (B, BL)
The instruction is only executed if the condition is true. The various conditions are defined Table 3-2. The
instruction encoding is shown in Figure 3-3, below.
31
28 27
25 24 23
0
L
Cond
101
Offset
[24] Link Bit
0 = Branch
1 = Branch with link
[31:28] Condition Field
Figure 3-3. Branch Instructions
Branch instructions contain a signed 2’s complement 24 bit offset. This is shifted left two bits, sign extended to 32
bits, and added to the PC. The instruction can therefore specify a branch of +/- 32Mbytes. The branch offset must
take account of the pre-fetch operation, which causes the PC to be 2 words (8 bytes) ahead of the current
instruction.
THE LINK BIT
Branch with Link (BL) writes the old PC into the link register (R14) of the current bank. The PC value written into
R14 is adjusted to allow for the pre-fetch, and contains the address of the instruction following the branch and link
instruction. Note that the CPSR is not saved with the PC and R14[1:0] are always cleared.
To return from a routine called by branch with link use MOV PC,R14 if the link register is still valid or LDM
Rn!,{..PC} if the link register has been saved onto a stack pointed to by Rn.
INSTRUCTION CYCLE TIMES
Branch and branch with link instructions take 2S + 1N incremental cycles, where S and N are defined as
sequential (S-cycle) and internal (I-cycle).
3-7
INSTRUCTION SET
S3C4510B
ASSEMBLER SYNTAX
Items in {} are optional. Items in < > must be present.
B{L}{cond} <expression>
{L}
Used to request the branch with link form of the instruction. If absent, R14 will not be
affected by the instruction.
{cond}
A two-character mnemonic as shown in Table 3-2. If absent then AL (Always) will be
used.
<expression>
The destination. The assembler calculates the offset.
Examples
here
BAL
B
CMP
here
there
R1,#0
; Assembles to 0xEAFFFFFE (note effect of PC offset).
; Always condition used as default.
; Compare R1 with zero and branch to fred
; if R1 was zero, otherwise continue.
; Continue to next instruction.
; Call subroutine at computed address.
; Add 1 to register 1, setting CPSR flags
; on the result then call subroutine if
; the C flag is clear, which will be the
; case unless R1 held 0xFFFFFFFF.
BEQ
BL
ADDS
fred
sub+ROM
R1,#1
BLCC
sub
3-8
S3C4510B
INSTRUCTION SET
DATA PROCESSING
The data processing instruction is only executed if the condition is true. The conditions are defined in Table 3-2.
The instruction encoding is shown in Figure 3-4.
31
28 27 26 25 24
21 20 19
16 15
12 11
0
00 Opcode
L
S
Rn
Rd
Cond
Operand2
[15:12] Destination Register
0 = Branch 1 = Branch with Link
[19:16] 1st operand Register
0 = Branch
1 = Branch with Link
[20] Set condition Codes
0 = Do not after condition codes
1 = Set condition codes
[24:21] Operation Code
0000 = AND-Rd: = Op1 AND Op2
0001 = EOR-Rd: = Op1 EOR Op2
0010 = SUB-Rd: = Op1-Op2
0011 = RSB-Rd: = Op2-Op1
0100 = ADD-Rd: = Op1+Op2
0101 = ADC-Rd: = Op1+Op2+C
0110 = SBC-Rd: = OP1-Op2+C-1
0111 = RSC-Rd: = Op2-Op1+C-1
1000 = TST-set condition codes on Op1 AND Op2
1001 = TEO-set condition codes on OP1 EOR Op2
1010 = CMP-set condition codes on Op1-Op2
1011 = SMN-set condition codes on Op1+Op2
1100 = ORR-Rd: = Op1 OR Op2
1101 = MOV-Rd: =OP2
1110 = BIC-Rd: = Op1 AND NOT Op2
1111 = MVN-Rd: = NOT Op2
[25] Immediate Operand
0 = Operand 2 is a register
1 = Operand 2 is an immediate Value
[11:0] Operand 2 Type Selection
11
3 4
0
Shift
Rm
[3:0] 2nd Operand Register
11 8 7
Rotate
[11:4] Shift applied to Rm
0
Imm
[7:0] Unsigned 8 bit immediate value
[11:8] Shift applied to Imm
[31:28] Condition Field
Figure 3-4. Data Processing Instructions
3-9
INSTRUCTION SET
S3C4510B
The instruction produces a result by performing a specified arithmetic or logical operation on one or two
operands. The first operand is always a register (Rn).
The second operand may be a shifted register (Rm) or a rotated 8 bit immediate value (Imm) according to the
value of the I bit in the instruction. The condition codes in the CPSR may be preserved or updated as a result of
this instruction, according to the value of the S bit in the instruction.
Certain operations (TST, TEQ, CMP, CMN) do not write the result to Rd. They are used only to perform tests and
to set the condition codes on the result and always have the S bit set. The instructions and their effects are listed
in Table 3-3.
3-10
S3C4510B
INSTRUCTION SET
CPSR FLAGS
The data processing operations may be classified as logical or arithmetic. The logical operations (AND, EOR,
TST, TEQ, ORR, MOV, BIC, MVN) perform the logical action on all corresponding bits of the operand or
operands to produce the result. If the S bit is set (and Rd is not R15, see below) the V flag in the CPSR will be
unaffected, the C flag will be set to the carry out from the barrel shifter (or preserved when the shift operation is
LSL #0), the Z flag will be set if and only if the result is all zeros, and the N flag will be set to the logical value of
bit 31 of the result.
Table 3-3. ARM Data Processing Instructions
Assembler Mnemonic
Opcode
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
Action
Operand1 AND operand2
AND
EOR
SUB
RSB
ADD
ADC
SBC
RSC
TST
Operand1 EOR operand2
Operand1 - operand2
Operand2 - operand1
Operand1 + operand2
Operand1 + operand2 + carry
Operand1 - operand2 + carry - 1
Operand2 - operand1 + carry - 1
As AND, but result is not written
As EOR, but result is not written
As SUB, but result is not written
As ADD, but result is not written
Operand1 OR operand2
TEQ
CMP
CMN
ORR
MOV
BIC
Operand2 (operand1 is ignored)
Operand1 AND NOT operand2 (Bit clear)
NOT operand2 (operand1 is ignored)
MVN
The arithmetic operations (SUB, RSB, ADD, ADC, SBC, RSC, CMP, CMN) treat each operand as a 32 bit integer
(either unsigned or 2's complement signed, the two are equivalent). If the S bit is set (and Rd is not R15) the V
flag in the CPSR will be set if an overflow occurs into bit 31 of the result; this may be ignored if the operands
were considered unsigned, but warns of a possible error if the operands were 2's complement signed. The C flag
will be set to the carry out of bit 31 of the ALU, the Z flag will be set if and only if the result was zero, and the N
flag will be set to the value of bit 31 of the result (indicating a negative result if the operands are considered to be
2's complement signed).
3-11
INSTRUCTION SET
SHIFTS
S3C4510B
When the second operand is specified to be a shifted register, the operation of the barrel shifter is controlled by
the shift field in the instruction. This field indicates the type of shift to be performed (logical left or right, arithmetic
right or rotate right). The amount by which the register should be shifted may be contained in an immediate field
in the instruction, or in the bottom byte of another register (other than R15). The encoding for the different shift
types is shown in Figure 3-5.
11
7
6
5
4
11
8
7
6
5
4
0
RS
0
1
[6:5] Shift Type
00 = logical left
10 = arithmetic right
[6:5] Shift Type
00 = logical left
10 = arithmetic right
01 = logical right
11 = rotate right
01 = logical right
11 = rotate right
[11:7] Shift Amount
5 bit unsigned integer
[11:8] Shift Register
Shift amount specified in bottom-byte of Rs
Figure 3-5. ARM Shift Operations
Instruction Specified Shift Amount
When the shift amount is specified in the instruction, it is contained in a 5 bit field which may take any value from
0 to 31. A logical shift left (LSL) takes the contents of Rm and moves each bit by the specified amount to a more
significant position. The least significant bits of the result are filled with zeros, and the high bits of Rm which do
not map into the result are discarded, except that the least significant discarded bit becomes the shifter carry
output which may be latched into the C bit of the CPSR when the ALU operation is in the logical class (see
above). For example, the effect of LSL #5 is shown in Figure 3-6.
31
27 26
0
Contents of Rm
carry out
Value of Operand 2
0
0
0
0
0
Figure 3-6. Logical Shift Left
NOTE
LSL #0 is a special case, where the shifter carry out is the old value of the CPSR C flag. The contents of
Rm are used directly as the second operand. A logical shift right (LSR) is similar, but the contents of Rm
are moved to less significant positions in the result. LSR #5 has the effect shown in Figure 3-7.
3-12
S3C4510B
INSTRUCTION SET
31
5
4
0
Contents of Rm
carry out
0
0
0
0
0
Value of Operand 2
Figure 3-7. Logical Shift Right
The form of the shift field which might be expected to correspond to LSR #0 is used to encode LSR #32, which
has a zero result with bit 31 of Rm as the carry output. Logical shift right zero is redundant as it is the same as
logical shift left zero, so the assembler will convert LSR #0 (and ASR #0 and ROR #0) into LSL #0, and allow
LSR #32 to be specified.
An arithmetic shift right (ASR) is similar to logical shift right, except that the high bits are filled with bit 31 of Rm
instead of zeros. This preserves the sign in 2's complement notation. For example, ASR #5 is shown in Figure 3-
8.
31 30
5
4
0
Contents of Rm
carry out
Value of Operand 2
Figure 3-8. Arithmetic Shift Right
The form of the shift field which might be expected to give ASR #0 is used to encode ASR #32. Bit 31 of Rm is
again used as the carry output, and each bit of operand 2 is also equal to bit 31 of Rm. The result is therefore all
ones or all zeros, according to the value of bit 31 of Rm.
3-13
INSTRUCTION SET
S3C4510B
Rotate right (ROR) operations reuse the bits which overshoot in a logical shift right operation by reintroducing
them at the high end of the result, in place of the zeros used to fill the high end in logical right operations. For
example, ROR #5 is shown in Figure 3-9. The form of the shift field which might be expected to give ROR #0 is
31
5
4
0
Contents of Rm
carry out
Value of Operand 2
Figure 3-9. Rotate Right
used to encode a special function of the barrel shifter, rotate right extended (RRX). This is a rotate right by one
bit position of the 33 bit quantity formed by appending the CPSR C flag to the most significant end of the
contents of Rm as shown in Figure 3-10.
31
1 0
Contents of Rm
carry out
C
in
Value of Operand 2
Figure 3-10. Rotate Right Extended
3-14
S3C4510B
INSTRUCTION SET
Register Specified Shift Amount
Only the least significant byte of the contents of Rs is used to determine the shift amount. Rs can be any general
register other than R15.
If this byte is zero, the unchanged contents of Rm will be used as the second operand, and the old value of the
CPSR C flag will be passed on as the shifter carry output.
If the byte has a value between 1 and 31, the shifted result will exactly match that of an instruction specified shift
with the same value and shift operation.
If the value in the byte is 32 or more, the result will be a logical extension of the shift described above:
1. LSL by 32 has result zero, carry out equal to bit 0 of Rm.
2. LSL by more than 32 has result zero, carry out zero.
3. LSR by 32 has result zero, carry out equal to bit 31 of Rm.
4. LSR by more than 32 has result zero, carry out zero.
5. ASR by 32 or more has result filled with and carry out equal to bit 31 of Rm.
6. ROR by 32 has result equal to Rm, carry out equal to bit 31 of Rm.
7. ROR by n where n is greater than 32 will give the same result and carry out as ROR by n-32; therefore
repeatedly subtract 32 from n until the amount is in the range 1 to 32 and see above.
NOTE
The zero in bit 7 of an instruction with a register controlled shift is compulsory; a one in this bit will cause
the instruction to be a multiply or undefined instruction.
3-15
INSTRUCTION SET
S3C4510B
IMMEDIATE OPERAND ROTATES
The immediate operand rotate field is a 4 bit unsigned integer which specifies a shift operation on the 8 bit
immediate value. This value is zero extended to 32 bits, and then subject to a rotate right by twice the value in
the rotate field. This enables many common constants to be generated, for example all powers of 2.
WRITING TO R15
When Rd is a register other than R15, the condition code flags in the CPSR may be updated from the ALU flags
as described above.
When Rd is R15 and the S flag in the instruction is not set the result of the operation is placed in R15 and the
CPSR is unaffected.
When Rd is R15 and the S flag is set the result of the operation is placed in R15 and the SPSR corresponding to
the current mode is moved to the CPSR. This allows state changes which atomically restore both PC and CPSR.
This form of instruction should not be used in User mode.
USING R15 AS AN OPERAND
If R15 (the PC) is used as an operand in a data processing instruction the register is used directly.
The PC value will be the address of the instruction, plus 8 or 12 bytes due to instruction prefetching. If the shift
amount is specified in the instruction, the PC will be 8 bytes ahead. If a register is used to specify the shift
amount the PC will be 12 bytes ahead.
TEQ, TST, CMP AND CMN OPCODES
NOTE
TEQ, TST, CMP and CMN do not write the result of their operation but do set flags in the CPSR. An
assembler should always set the S flag for these instructions even if this is not specified in the
mnemonic.
The TEQP form of the TEQ instruction used in earlier ARM processors must not be used: the PSR
transfer operations should be used instead.
The action of TEQP in the ARM7TDMI is to move SPSR_<mode> to the CPSR if the processor is in a
privileged mode and to do nothing if in User mode.
3-16
S3C4510B
INSTRUCTION SET
INSTRUCTION CYCLE TIMES
Data processing instructions vary in the number of incremental cycles taken as follows:
Table 3-4. Incremental Cycle Times
Processing Type
Cycles
Normal data processing
1S
Data processing with register specified shift
Data processing with PC written
1S + 1I
2S + 1N
Data processing with register specified shift and PC written
2S + 1N + 1I
NOTE: S, N and I are as defined sequential (S-cycle), non-sequential (N-cycle), and internal (I-cycle) respectively.
ASSEMBLER SYNTAX
— MOV,MVN (single operand instructions).
<opcode>{cond}{S} Rd,<Op2>
— CMP,CMN,TEQ,TST (instructions which do not produce a result).
<opcode>{cond} Rn,<Op2>
— AND,EOR,SUB,RSB,ADD,ADC,SBC,RSC,ORR,BIC
<opcode>{cond}{S} Rd,Rn,<Op2>
where:
<Op2>
Rm{,<shift>} or,<#expression>
{cond}
A two-character condition mnemonic. See Table 3-2.
Set condition codes if S present (implied for CMP, CMN, TEQ, TST).
Expressions evaluating to a register number.
{S}
Rd, Rn and Rm
<#expression>
If this is used, the assembler will attempt to generate a shifted immediate 8-bit field
to match the expression. If this is impossible, it will give an error.
<shift>
<Shiftname> <register> or <shiftname> #expression, or RRX (rotate right one bit
with extend).
<shiftname>s
ASL, LSL, LSR, ASR, ROR. (ASL is a synonym for LSL, they assemble to the same
code.)
3-17
INSTRUCTION SET
Examples
S3C4510B
ADDEQ
TEQS
R2,R4,R5
R4,#3
; If the Z flag is set make R2: = R4 + R5
; Test R4 for equality with 3.
; (The S is in fact redundant as the
; assembler inserts it automatically.)
; Logical right shift R7 by the number in
; the bottom byte of R2, subtract result
; from R5, and put the answer into R4.
; Return from subroutine.
SUB
R4,R5,R7,LSR R2
MOV
MOVS
PC,R14
PC,R14
; Return from exception and restore CPSR
; from SPSR_mode.
3-18
S3C4510B
INSTRUCTION SET
PSR TRANSFER (MRS, MSR)
The instruction is only executed if the condition is true. The various conditions are defined in Table 3-2.
The MRS and MSR instructions are formed from a subset of the data processing operations and are implemented
using the TEQ, TST, CMN and CMP instructions without the S flag set. The encoding is shown in Figure 3-11.
These instructions allow access to the CPSR and SPSR registers. The MRS instruction allows the contents of the
CPSR or SPSR_<mode> to be moved to a general register. The MSR instruction allows the contents of a general
register to be moved to the CPSR or SPSR_<mode> register.
The MSR instruction also allows an immediate value or register contents to be transferred to the condition code
flags (N,Z,C and V) of CPSR or SPSR_<mode> without affecting the control bits. In this case, the top four bits of
the specified register contents or 32 bit immediate value are written to the top four bits of the relevant PSR.
OPERAND RESTRICTIONS
— In user mode, the control bits of the CPSR are protected from change, so only the condition code flags of the
CPSR can be changed. In other (privileged) modes the entire CPSR can be changed.
— Note that the software must never change the state of the T bit in the CPSR. If this happens, the processor
will enter an unpredictable state.
— The SPSR register which is accessed depends on the mode at the time of execution. For example, only
SPSR_fiq is accessible when the processor is in FIQ mode.
— You must not specify R15 as the source or destination register.
— Also, do not attempt to access an SPSR in User mode, since no such register exists.
3-19
INSTRUCTION SET
S3C4510B
MRS (Transfer PSR Contents to a Register)
31
28 27
23 22 21
16 15
12 11
0
Ps
00010
001111
Rd
Cond
000000000000
[15:21] Destination Register
[19:16] Source PSR
0 = CPSR
1 = SPSR_<current mode>
[31:28] Condition Field
MRS (Transfer Register Contents to PSR)
31
28 27
23 22 21
12 11
4
3
0
Pd
00010
101001111
Cond
00000000
Rm
[3:0] Source Register
[22] Destination PSR
0 = CPSR
1 = SPSR_<current mode>
[31:28] Condition Field
MRS (Transfer Register Contents or Immediate Value to PSR Flag Bits Only)
31 28 27 26 25 24 23 22 21 12 11
Pd
0
00
I
10
101001111
Cond
Soucer Operand
[22] Destination PSR
0 = CPSR 1 = SPSR_<current mode>
[25] Immediate Operand
0 = Source operand is a register
1 = SPSR_<current mode>
[11:0] Source Operand
11
4
3
0
00000000
Rm
[3:0] Source Register
[11:4] Source operand is an immediate value
11
8
7
0
Rotate
Imm
[7:0] Unsigned 8 bit immediate value
[11:8] Shift applied to Imm
[31:28] Condition Field
Figure 3-11. PSR Transfer
3-20
S3C4510B
INSTRUCTION SET
RESERVED BITS
Only twelve bits of the PSR are defined in ARM7TDMI (N, Z, C, V, I, F, T & M[4:0]); the remaining bits are
reserved for use in future versions of the processor. Refer to Figure 2-6 for a full description of the PSR bits.
To ensure the maximum compatibility between ARM7TDMI programs and future processors, the following rules
should be observed:
— The reserved bits should be preserved when changing the value in a PSR.
— Programs should not rely on specific values from the reserved bits when checking the PSR status, since they
may read as one or zero in future processors.
A read-modify-write strategy should therefore be used when altering the control bits of any PSR register; this
involves transferring the appropriate PSR register to a general register using the MRS instruction, changing only
the relevant bits and then transferring the modified value back to the PSR register using the MSR instruction.
Examples
The following sequence performs a mode change:
MRS
BIC
ORR
MSR
R0,CPSR
; Take a copy of the CPSR.
; Clear the mode bits.
; Select new mode
R0,R0,#0x1F
R0,R0,#new_mode
CPSR,R0
; Write back the modified CPSR.
When the aim is simply to change the condition code flags in a PSR, a value can be written directly to the flag
bits without disturbing the control bits. The following instruction sets the N, Z, C and V flags:
MSR
CPSR_flg,#0xF0000000
; Set all the flags regardless of their previous state
; (does not affect any control bits).
No attempt should be made to write an 8 bit immediate value into the whole PSR since such an operation cannot
preserve the reserved bits.
INSTRUCTION CYCLE TIMES
PSR transfers take 1S incremental cycles, where S is defined as sequential (S-cycle).
3-21
INSTRUCTION SET
S3C4510B
ASSEMBLER SYNTAX
— MRS - transfer PSR contents to a register
MRS{cond} Rd,<psr>
— MSR - transfer register contents to PSR
MSR{cond} <psr>,Rm
— MSR - transfer register contents to PSR flag bits only
MSR{cond} <psrf>,Rm
The most significant four bits of the register contents are written to the N,Z,C & V flags respectively.
— MSR - transfer immediate value to PSR flag bits only
MSR{cond} <psrf>, <#expression>
The expression should symbolise a 32 bit value of which the most significant four bits are written to the N, Z, C
and V flags respectively.
Key:
{cond}
Two-character condition mnemonic. See Table 3-2.
Expressions evaluating to a register number other than R15
CPSR, CPSR_all, SPSR or SPSR_all. (CPSR and CPSR_all are synonyms as are
and SPSR_all)
Rd and Rm
<psr>
SPSR
<psrf>
CPSR_flg or SPSR_flg
<#expression>
Where this is used, the assembler will attempt to generate a shifted immediate 8-bit
field to match the expression. If this is impossible, it will give an error.
Examples
In User mode the instructions behave as follows:
MSR
MSR
MSR
MRS
CPSR_all,Rm
CPSR_flg,Rm
; CPSR[31:28] ¬ Rm[31:28]
; CPSR[31:28] ¬ Rm[31:28]
CPSR_flg,#0xA0000000 ; CPSR[31:28] ¬ 0xA (set N, C; clear Z, V)
Rd,CPSR
; Rd[31:0] ¬ CPSR[31:0]
In privileged modes the instructions behave as follows:
MSR
MSR
MSR
MSR
MSR
MSR
MRS
CPSR_all,Rm
CPSR_flg,Rm
; CPSR[31:0] ¬ Rm[31:0]
; CPSR[31:28] ¬ Rm[31:28]
CPSR_flg,#0x50000000 ; CPSR[31:28] ¬ 0x5 (set Z, V; clear N, C)
SPSR_all,Rm
SPSR_flg,Rm
SPSR_flg,#0xC0000000 ; SPSR_<mode>[31:28] ¬ 0xC (set N, Z; clear C, V)
Rd,SPSR ; Rd[31:0] ¬ SPSR_<mode>[31:0]
; SPSR_<mode>[31:0] ¬ Rm[31:0]
; SPSR_<mode>[31:28] ¬ Rm[31:28]
3-22
S3C4510B
INSTRUCTION SET
MULTIPLY AND MULTIPLY-ACCUMULATE (MUL, MLA)
The instruction is only executed if the condition is true. The various conditions are defined in Table 3-2. The
instruction encoding is shown in Figure 3-12.
The multiply and multiply-accumulate instructions use an 8 bit Booth's algorithm to perform integer multiplication.
31
28 27
22 21 20 19
16 15
12 11
8
7
4
3
0
0 0 0 0 0 0 A S
Rd
Rn
Rs
Rm
Cond
1 0 0 1
[15:12][11:8][3:0] Operand Registers
[19:16] Destination Register
[20] Set Condition Code
0 = Do not alter condition codes
1 = Set condition codes
[21] Accumulate
0 = Multiply only
1 = Multiply and accumulate
[31:28] Condition Field
Figure 3-12. Multiply Instructions
The multiply form of the instruction gives Rd: = Rm * Rs. Rn is ignored, and should be set to zero for
compatibility with possible future upgrades to the instruction set. The multiply-accumulate form gives Rd: = Rm *
Rs + Rn, which can save an explicit ADD instruction in some circumstances. Both forms of the instruction work
on operands which may be considered as signed (2’ complement) or unsigned integers.
The results of a signed multiply nd of an unsigned multiply of 32 bit operands differ only in the upper 32 bits-the
low 32 bits of the signed and unsigned results are identical. As these instructions only produce the low 32 bits of a
multiply, they can be used for both signed and unsigned multiplies.
For example consider the multiplication of the operands:
Operand A
Operand B
Result
0xFFFFFFF6 0x0000001
0xFFFFFF38
If the Operands are Interpreted as Signed
Operand A has the value -10, operand B has the value 20, and the result is -200 which is correctly represented as
0xFFFFFF38.
If the Operands are Interpreted as Unsigned
Operand A has the value 4294967286, operand B has the value 20 and the result is 85899345720, which is
represented as 0x13FFFFFF38, so the least significant 32 bits are 0xFFFFFF38.
Operand Restrictions
The destination register Rd must not be the same as the operand register Rm. R15 must not be used as an
operand or as the destination register.
All other register combinations will give correct results, and Rd, Rn and Rs may use the same register when
required.
3-23
INSTRUCTION SET
CPSR FLAGS
S3C4510B
Setting the CPSR flags is optional, and is controlled by the S bit in the instruction. The N (Negative) and Z (Zero)
flags are set correctly on the result (N is made equal to bit 31 of the result, and Z is set if and only if the result is
zero). The C (Carry) flag is set to a meaningless value and the V (overflow) flag is unaffected.
INSTRUCTION CYCLE TIMES
MUL takes 1S + mI and MLA 1S + (m+1)I cycles to execute, where S and I are defined as sequential (S-cycle)
and internal (I-cycle), respectively.
m
The number of 8 bit multiplier array cycles is required to complete the multiply,
which is controlled by the value of the multiplier operand specified by Rs.
Its possible values are as follows
1
2
3
4
If bits [32:8] of the multiplier operand are all zero or all one.
If bits [32:16] of the multiplier operand are all zero or all one.
If bits [32:24] of the multiplier operand are all zero or all one.
In all other cases.
ASSEMBLER SYNTAX
MUL{cond}{S} Rd,Rm,Rs
MLA{cond}{S} Rd,Rm,Rs,Rn
{cond}
Two-character condition mnemonic. See Table 3-2.
{S}
Set condition codes if S present
Rd, Rm, Rs and Rn
Expressions evaluating to a register number other than R15.
Examples
MUL
R1,R2,R3
; R1: = R2 * R3
MLAEQS
R1,R2,R3,R4
; Conditionally R1: = R2 * R3 + R4, setting condition
codes.
3-24
S3C4510B
INSTRUCTION SET
MULTIPLY LONG AND MULTIPLY-ACCUMULATE LONG (MULL,MLAL)
The instruction is only executed if the condition is true. The various conditions are defined in Table 3-2. The
instruction encoding is shown in Figure 3-13.
The multiply long instructions perform integer multiplication on two 32 bit operands and produce 64 bit results.
Signed and unsigned multiplication each with optional accumulate give rise to four variations.
31
28 27
23 22 21 20 19
16 15
12 11
8
7
4
3
0
0 0 0 0 1 U A S
RdHi
RdLo
Rs
Rm
Cond
1 0 0 1
[11:8][3:0] Operand Registers
[19:16][15:12] Source Destination Registers
[20] Set Condition Code
0 = Do not alter condition codes
1 = Set condition codes
[21] Accumulate
0 = Multiply only
1 = Multiply and accumulate
[22] Unsigned
0 = Unsigned
1 = Signed
[31:28] Condition Field
Figure 3-13. Multiply Long Instructions
The multiply forms (UMULL and SMULL) take two 32 bit numbers and multiply them to produce a 64 bit result of
the form RdHi, RdLo: = Rm * Rs. The lower 32 bits of the 64 bit result are written to RdLo, the upper 32 bits of
the result are written to RdHi.
The multiply-accumulate forms (UMLAL and SMLAL) take two 32 bit numbers, multiply them and add a 64 bit
number to produce a 64 bit result of the form RdHi, RdLo: = Rm * Rs + RdHi, RdLo. The lower 32 bits of the 64
bit number to add is read from RdLo. The upper 32 bits of the 64 bit number to add is read from RdHi. The lower
32 bits of the 64 bit result are written to RdLo. The upper 32 bits of the 64 bit result are written to RdHi.
The UMULL and UMLAL instructions treat all of their operands as unsigned binary numbers and write an
unsigned 64 bit result. The SMULL and SMLAL instructions treat all of their operands as two's-complement
signed numbers and write a two's-complement signed 64 bit result.
OPERAND RESTRICTIONS
— R15 must not be used as an operand or as a destination register.
— RdHi, RdLo, and Rm must all specify different registers.
3-25
INSTRUCTION SET
CPSR FLAGS
S3C4510B
Setting the CPSR flags is optional, and is controlled by the S bit in the instruction. The N and Z flags are set
correctly on the result (N is equal to bit 63 of the result, Z is set if and only if all 64 bits of the result are zero).
Both the C and V flags are set to meaningless values.
INSTRUCTION CYCLE TIMES
MULL takes 1S + (m+1)I and MLAL 1S + (m+2)I cycles to execute, where m is the number of 8 bit multiplier
array cycles required to complete the multiply, which is controlled by the value of the multiplier operand specified
by Rs.
Its possible values are as follows:
For Signed Instructions SMULL, SMLAL:
— If bits [31:8] of the multiplier operand are all zero or all one.
— If bits [31:16] of the multiplier operand are all zero or all one.
— If bits [31:24] of the multiplier operand are all zero or all one.
— In all other cases.
For Unsigned Instructions UMULL, UMLAL:
— If bits [31:8] of the multiplier operand are all zero.
— If bits [31:16] of the multiplier operand are all zero.
— If bits [31:24] of the multiplier operand are all zero.
— In all other cases.
S and I are defined as sequential (S-cycle) and internal (I-cycle), respectively.
3-26
S3C4510B
INSTRUCTION SET
ASSEMBLER SYNTAX
Table 3-5. Assembler Syntax Descriptions
Description
Mnemonic
Purpose
UMULL{cond}{S} RdLo, RdHi, Rm, Rs
UMLAL{cond}{S} RdLo, RdHi, Rm, Rs
SMULL{cond}{S} RdLo, RdHi, Rm, Rs
SMLAL{cond}{S} RdLo, RdHi, Rm, Rs
Unsigned multiply long
32 x 32 = 64
Unsigned multiply & Accumulate long
Signed multiply long
32 x 32 + 64 = 64
32 x 32 = 64
Signed multiply & Accumulate long
32 x 32 + 64 = 64
where:
{cond}
Two-character condition mnemonic. See Table 3-2.
Set condition codes if S present
{S}
RdLo, RdHi, Rm, Rs
Expressions evaluating to a register number other than R15.
Examples
UMULL
UMLALS
R1, R4, R2, R3
R1, R5, R2, R3
; R4, R1: = R2 * R3
; R5, R1: = R2 * R3 + R5, R1 also setting condition codes
3-27
INSTRUCTION SET
S3C4510B
SINGLE DATA TRANSFER (LDR, STR)
The instruction is only executed if the condition is true. The various conditions are defined in Table 3-2. The
instruction encoding is shown in Figure 3-14.
The single data transfer instructions are used to load or store single bytes or words of data. The memory address
used in the transfer is calculated by adding an offset to or subtracting an offset from a base register.
The result of this calculation may be written back into the base register if auto-indexing is required.
31
28 27 26 25 24 23 22 21 20 19
01 P U B W L
16 15
12 11
0
I
Rn
Rd
Offset
Cond
[15:12] Source/Destination Registers
[19:16] Base Register
[20] Load/Store Bit
0 = Store to memory
1 = Load from memory
[21] Write-back Bit
0 = No write-back
1 = Write address into base
[22] Byte/Word Bit
0 = Transfer word quantity
1 = Transfer byte quantity
[23] Up/Down Bit
0 = Down: subtract offset from base
1 = Up: add offset to base
[24] Pre/Post Indexing Bit
0 = Post: add offset after transfer
1 = Pre: add offset bofore transfer
[25] Immediate Offset
0 = Offset is an immediate value
[11:0] Offset
11
0
Immediate
[11:0] Unsigned 12-bit immediate offset
11
4
3
0
Shift
Rm
[3:0] Offset register [11:4] Shift applied to Rm
[31:28] Condition Field
Figure 3-14. Single Data Transfer Instructions
3-28
S3C4510B
INSTRUCTION SET
OFFSETS AND AUTO-INDEXING
The offset from the base may be either a 12 bit unsigned binary immediate value in the instruction, or a second
register (possibly shifted in some way). The offset may be added to (U = 1) or subtracted from (U = 0) the base
register Rn. The offset modification may be performed either before (pre-indexed, P = 1) or after (post-indexed, P
= 0) the base is used as the transfer address.
The W bit gives optional auto increment and decrement addressing modes. The modified base value may be
written back into the base (W = 1), or the old base value may be kept (W = 0). In the case of post-indexed
addressing, the write back bit is redundant and is always set to zero, since the old base value can be retained by
setting the offset to zero. Therefore post-indexed data transfers always write back the modified base. The only
use of the W bit in a post-indexed data transfer is in privileged mode code, where setting the W bit forces non-
privileged mode for the transfer, allowing the operating system to generate a user address in a system where the
memory management hardware makes suitable use of this hardware.
SHIFTED REGISTER OFFSET
The 8 shift control bits are described in the data processing instructions section. However, the register specified
shift amounts are not available in this instruction class. See Figure 3-5.
BYTES AND WORDS
This instruction class may be used to transfer a byte (B = 1) or a word (B = 0) between an ARM7TDMI register
and memory.
The action of LDR(B) and STR(B) instructions is influenced by the BIGEND control signal of ARM7TDMI core.
The two possible configurations are described below.
Little-Endian Configuration
A byte load (LDRB) expects the data on data bus inputs 7 through 0 if the supplied address is on a word
boundary, on data bus inputs 15 through 8 if it is a word address plus one byte, and so on. The selected byte is
placed in the bottom 8 bits of the destination register, and the remaining bits of the register are filled with zeros.
Please see Figure 2-2.
A byte store (STRB) repeats the bottom 8 bits of the source register four times across data bus outputs 31
through 0. The external memory system should activate the appropriate byte subsystem to store the data.
A word load (LDR) will normally use a word aligned address. However, an address offset from a word boundary
will cause the data to be rotated into the register so that the addressed byte occupies bits 0 to 7. This means that
half-words accessed at offsets 0 and 2 from the word boundary will be correctly loaded into bits 0 through 15 of
the register. Two shift operations are then required to clear or to sign extend the upper 16 bits.
A word store (STR) should generate a word aligned address. The word presented to the data bus is not affected if
the address is not word aligned. That is, bit 31 of the register being stored always appears on data bus output 31.
3-29
INSTRUCTION SET
S3C4510B
Memory
A
Register
A
A+3
24
24
B
C
D
B
C
D
A+2
A+1
A
16
16
8
8
0
0
LDR from word aligned address
Memory
A
Register
A
A+3
24
24
B
C
D
B
C
D
A+2
A+1
A
16
16
8
8
0
0
LDR from address offset by 2
Figure 3-15. Little-Endian Offset Addressing
Big-Endian Configuration
A byte load (LDRB) expects the data on data bus inputs 31 through 24 if the supplied address is on a word
boundary, on data bus inputs 23 through 16 if it is a word address plus one byte, and so on. The selected byte is
placed in the bottom 8 bits of the destination register and the remaining bits of the register are filled with zeros.
Please see Figure 2-1.
A byte store (STRB) repeats the bottom 8 bits of the source register four times across data bus outputs 31
through 0. The external memory system should activate the appropriate byte subsystem to store the data.
A word load (LDR) should generate a word aligned address. An address offset of 0 or 2 from a word boundary will
cause the data to be rotated into the register so that the addressed byte occupies bits 31 through 24. This means
that half-words accessed at these offsets will be correctly loaded into bits 16 through 31 of the register. A shift
operation is then required to move (and optionally sign extend) the data into the bottom 16 bits. An address offset
of 1 or 3 from a word boundary will cause the data to be rotated into the register so that the addressed byte
occupies bits 15 through 8.
A word store (STR) should generate a word aligned address. The word presented to the data bus is not affected if
the address is not word aligned. That is, bit 31 of the register being stored always appears on data bus output 31.
3-30
S3C4510B
INSTRUCTION SET
USE OF R15
Write-back must not be specified if R15 is specified as the base register (Rn). When using R15 as the base
register you must remember it contains an address 8 bytes on from the address of the current instruction.
R15 must not be specified as the register offset (Rm).
When R15 is the source register (Rd) of a register store (STR) instruction, the stored value will be address of the
instruction plus 12.
RESTRICTION ON THE USE OF BASE REGISTER
When configured for late aborts, the following example code is difficult to unwind as the base register, Rn, gets
updated before the abort handler starts. Sometimes it may be impossible to calculate the initial value.
After an abort, the following example code is difficult to unwind as the base register, Rn, gets updated before the
abort handler starts. Sometimes it may be impossible to calculate the initial value.
Example:
LDR
R0,[R1],R1
Therefore a post-indexed LDR or STR where Rm is the same register as Rn should not be used.
DATA ABORTS
A transfer to or from a legal address may cause problems for a memory management system. For instance, in a
system which uses virtual memory the required data may be absent from main memory. The memory manager
can signal a problem by taking the processor ABORT input HIGH whereupon the data abort trap will be taken. It
is up to the system software to resolve the cause of the problem, then the instruction can be restarted and the
original program continued.
INSTRUCTION CYCLE TIMES
Normal LDR instructions take 1S + 1N + 1I and LDR PC take 2S + 2N +1I incremental cycles, where S,N and I
are defined as sequential (S-cycle), non-sequential (N-cycle), and internal (I-cycle), respectively. STR instructions
take 2N incremental cycles to execute.
3-31
INSTRUCTION SET
S3C4510B
ASSEMBLER SYNTAX
<LDR|STR>{cond}{B}{T} Rd,<Address>
where:
LDR
STR
{cond}
{B}
Load from memory into a register
Store from a register into memory
Two-character condition mnemonic. See Table 3-2.
If B is present then byte transfer, otherwise word transfer
If T is present the W bit will be set in a post-indexed instruction, forcing non-
{T}
privileged mode for the transfer cycle. T is not allowed when a pre-indexed
addressing mode is specified or implied.
Rd
An expression evaluating to a valid register number.
Rn and Rm
Expressions evaluating to a register number. If Rn is R15 then the assembler will
subtract 8 from the offset value to allow for ARM7TDMI pipelining. In this case base
write-back should not be specified.
<Address>can be:
1
An expression which generates an address:
The assembler will attempt to generate an instruction using the PC as a base and a
corrected immediate offset to address the location given by evaluating the
expression. This will be a PC relative, pre-indexed address. If the address is out of
range, an error will be generated.
2
3
A pre-indexed addressing specification:
[Rn]
[Rn,<#expression>]{!}
[Rn,{+/-}Rm{,<shift>}]{!}
offset of zero
offset of <expression> bytes
offset of +/- contents of index register,
shifted by <shift>
A post-indexed addressing specification:
[Rn],<#expression>
[Rn],{+/-}Rm{,<shift>}
offset of <expression> bytes
offset of +/- contents of index register,
shifted as by <shift>.
<shift>
{!}
General shift operation (see data processing instructions) but you cannot specify
the shift amount by a register.
Writes back the base register (set the W bit) if! is present.
3-32
S3C4510B
Examples
INSTRUCTION SET
STR
R1,[R2,R4]!
; Store R1 at R2 + R4 (both of which are registers)
; and write back address to R2.
STR
LDR
LDR
LDREQB
R1,[R2],R4
; Store R1 at R2 and write back R2 + R4 to R2.
; Load R1 from contents of R2 + 16, but don't write back.
; Load R1 from contents of R2 + R3 * 4.
; Conditionally load byte at R6 + 5 into
R1,[R2,#16]
R1,[R2,R3,LSL#2]
R1,[R6,#5]
; R1 bits 0 to 7, filling bits 8 to 31 with zeros.
; Generate PC relative offset to address PLACE.
STR
R1,PLACE
PLACE
3-33
INSTRUCTION SET
S3C4510B
HALFWORD AND SIGNED DATA TRANSFER (LDRH/STRH/LDRSB/LDRSH)
The instruction is only executed if the condition is true. The various conditions are defined in Table 3-2. The
instruction encoding is shown in Figure 3-16.
These instructions are used to load or store half-words of data and also load sign-extended bytes or half-words of
data. The memory address used in the transfer is calculated by adding an offset to or subtracting an offset from a
base register. The result of this calculation may be written back into the base register if auto-indexing is required.
31
28 27
25 24 23 22 21 20 19
16 15
12 11
8
7
6
5
4
3
0
000
P U 0 W L
Rn
Rd
0000
1 S H 1
Rm
Cond
[3:0] Offset Register
[6][5] S H
0 0 = SWP instruction
0 1 = Unsigned halfwords
1 1 = Signed byte
1 1 = Signed half words
[15:12] Source/Destination Register
[19:16] Base Register
[20] Load/Store
0 = Store to memory
1 = Load from memory
[21] Write-back
0 = No write-back
1 = Write address into base
[23] Up/Down
0 = Down: subtract offset from base
1 = Up: add offset to base
[24] Pre/Post Indexing
0 = Post: add/subtract offset after transfer
1 = Pre: add/subtract offset bofore transfer
[31:28] Condition Field
Figure 3-16. Half-word and Signed Data Transfer with Register Offset
3-34
S3C4510B
INSTRUCTION SET
31
28 27
25 24 23 22 21 20 19
16 15
12 11
8
7
6
5
4
3
0
000
P U 1 W L
Rn
Rd
Offset
1 S H 1
Offset
Cond
[3:0] Immediate Offset (Low Nibble)
[6][5] S H
0 0 = SWP instruction
0 1 = Unsigned halfwords
1 1 = Signed byte
1 1 = Signed half words
[11:8] Immediate Offset (High Nibble)
[15:12] Source/Destination Register
[19:16] Base Register
[20] Load/Store
0 = Store to memory
1 = Load from memory
[21] Write-back
0 = No write-back
1 = Write address into base
[23] Up/Down
0 = Down: subtract offset from base
1 = Up: add offset to base
[24] Pre/Post Indexing
0 = Post: add/subtract offset after transfer
1 = Pre: add/subtract offset bofore transfer
[31:28] Condition Field
Figure 3-17. Half-word and Signed Data Transfer with Immediate Offset and Auto-Indexing
OFFSETS AND AUTO-INDEXING
The offset from the base may be either a 8-bit unsigned binary immediate value in the instruction, or a second
register. The 8-bit offset is formed by concatenating bits 11 to 8 and bits 3 to 0 of the instruction word, such that
bit 11 becomes the MSB and bit 0 becomes the LSB. The offset may be added to (U = 1) or subtracted from (U =
0) the base register Rn. The offset modification may be performed either before (pre-indexed, P = 1) or after
(post-indexed, P = 0) the base register is used as the transfer address.
The W bit gives optional auto-increment and decrement addressing modes. The modified base value may be
written back into the base (W = 1), or the old base may be kept (W = 0). In the case of post-indexed addressing,
the write back bit is redundant and is always set to zero, since the old base value can be retained if necessary by
setting the offset to zero. Therefore post-indexed data transfers always write back the modified base.
The Write-back bit should not be set high (W = 1) when post-indexed addressing is selected.
3-35
INSTRUCTION SET
S3C4510B
HALF-WORD LOAD AND STORES
Setting S = 0 and H = 1 may be used to transfer unsigned Half-words between an ARM7TDMI register and
memory.
The action of LDRH and STRH instructions is influenced by the BIGEND control signal. The two possible
configurations are described in the section below.
SIGNED BYTE AND HALF-WORD LOADS
The S bit controls the loading of sign-extended data. When S = 1 the H bit selects between Bytes (H = 0) and
Half-words (H = 1). The L bit should not be set low (Store) when Signed (S = 1) operations have been selected.
The LDRSB instruction loads the selected Byte into bits 7 to 0 of the destination register and bits 31 to 8 of the
destination register are set to the value of bit 7, the sign bit.
The LDRSH instruction loads the selected Half-word into bits 15 to 0 of the destination register and bits 31 to 16
of the destination register are set to the value of bit 15, the sign bit.
The action of the LDRSB and LDRSH instructions is influenced by the BIGEND control signal. The two possible
configurations are described in the following section.
ENDIANNESS AND BYTE/HALF-WORD SELECTION
Little-Endian Configuration
A signed byte load (LDRSB) expects data on data bus inputs 7 through to 0 if the supplied address is on a word
boundary, on data bus inputs 15 through to 8 if it is a word address plus one byte, and so on. The selected byte is
placed in the bottom 8 bit of the destination register, and the remaining bits of the register are filled with the sign
bit, bit 7 of the byte. Please see Figure 2-2.
A half-word load (LDRSH or LDRH) expects data on data bus inputs 15 through to 0 if the supplied address is on
a word boundary and on data bus inputs 31 through to 16 if it is a half-word boundary, (A[1]=1).The supplied
address should always be on a half-word boundary. If bit 0 of the supplied address is high then the ARM7TDMI
will load an unpredictable value. The selected half-word is placed in the bottom 16 bits of the destination register.
For unsigned half-words (LDRH), the top 16 bits of the register are filled with zeros and for signed half-words
(LDRSH) the top 16 bits are filled with the sign bit, bit 15 of the half-word.
A half-word store (STRH) repeats the bottom 16 bits of the source register twice across the data bus outputs 31
through to 0. The external memory system should activate the appropriate half-word subsystem to store the data.
Note that the address must be half-word aligned, if bit 0 of the address is high this will cause unpredictable
behaviour.
3-36
S3C4510B
INSTRUCTION SET
Big-Endian Configuration
A signed byte load (LDRSB) expects data on data bus inputs 31 through to 24 if the supplied address is on a
word boundary, on data bus inputs 23 through to 16 if it is a word address plus one byte, and so on. The selected
byte is placed in the bottom 8 bit of the destination register, and the remaining bits of the register are filled with
the sign bit, bit 7 of the byte. Please see Figure 2-1.
A half-word load (LDRSH or LDRH) expects data on data bus inputs 31 through to 16 if the supplied address is on
a word boundary and on data bus inputs 15 through to 0 if it is a half-word boundary, (A[1] =1). The supplied
address should always be on a half-word boundary. If bit 0 of the supplied address is high then the ARM7TDMI
will load an unpredictable value. The selected half-word is placed in the bottom 16 bits of the destination register.
For unsigned half-words (LDRH), the top 16 bits of the register are filled with zeros and for signed half-words
(LDRSH) the top 16 bits are filled with the sign bit, bit 15 of the half-word.
A half-word store (STRH) repeats the bottom 16 bits of the source register twice across the data bus outputs 31
through to 0. The external memory system should activate the appropriate half-word subsystem to store the data.
Note that the address must be half-word aligned, if bit 0 of the address is HIGH this will cause unpredictable
behaviour.
USE OF R15
Write-back should not be specified if R15 is specified as the base register (Rn). When using R15 as the base
register you must remember it contains an address 8 bytes on from the address of the current instruction.
R15 should not be specified as the register offset (Rm).
When R15 is the source register (Rd) of a Half-word store (STRH) instruction, the stored address will be address
of the instruction plus 12.
DATA ABORTS
A transfer to or from a legal address may cause problems for a memory management system. For instance, in a
system which uses virtual memory the required data may be absent from the main memory. The memory
manager can signal a problem by taking the processor ABORT input high whereupon the data abort trap will be
taken. It is up to the system software to resolve the cause of the problem, then the instruction can be restarted
and the original program continued.
INSTRUCTION CYCLE TIMES
Normal LDR(H, SH, SB) instructions take 1S + 1N + 1I. LDR(H, SH, SB) PC take 2S + 2N + 1I incremental
cycles. S,N and I are defined as sequential (S-cycle), non-sequential (N-cycle), and internal (I-cycle),
respectively. STRH instructions take 2N incremental cycles to execute.
3-37
INSTRUCTION SET
S3C4510B
ASSEMBLER SYNTAX
<LDR|STR>{cond}<H|SH|SB> Rd,<address>
LDR
STR
{cond}
H
Load from memory into a register
Store from a register into memory
Two-character condition mnemonic. See Table 3-2.
Transfer half-word quantity
SB
Load sign extended byte (Only valid for LDR)
Load sign extended half-word (Only valid for LDR)
An expression evaluating to a valid register number.
SH
Rd
<address> can be:
1
An expression which generates an address:
The assembler will attempt to generate an instruction using the PC as a base and a
corrected immediate offset to address the location given by evaluating the
expression. This will be a PC relative, pre-indexed address. If the address is out of
range, an error will be generated.
2
A pre-indexed addressing specification:
[Rn]
offset of zero
[Rn,<#expression>]{!}
[Rn,{+/-}Rm]{!}
offset of <expression> bytes
offset of +/- contents of index register
3
A post-indexed addressing specification:
[Rn],<#expression>
[Rn],{+/-}Rm
offset of <expression> bytes
offset of +/- contents of index register.
4
Rn and Rm are expressions evaluating to a register number. If Rn is R15 then the
assembler will subtract 8 from the offset value to allow for ARM7TDMI pipelining.
In this case base write-back should not be specified.
{!}
Writes back the base register (set the W bit) if ! is present.
3-38
S3C4510B
Examples
INSTRUCTION SET
LDRH
R1,[R2,-R3]!
; Load R1 from the contents of the half-word address
; contained in R2-R3 (both of which are registers)
; and write back address to R2
STRH
LDRSB
R3,[R4,#14]
R8,[R2],#-223
; Store the half-word in R3 at R14+14 but don't write back.
; Load R8 with the sign extended contents of the byte
; address contained in R2 and write back R2-223 to R2.
; Conditionally load R11 with the sign extended contents
; of the half-word address contained in R0.
LDRNESH R11,[R0]
HERE
; Generate PC relative offset to address FRED.
STRH
FRED
R5, [PC,#(FRED-HERE-8)]; Store the half-word in R5 at address FRED
3-39
INSTRUCTION SET
S3C4510B
BLOCK DATA TRANSFER (LDM, STM)
The instruction is only executed if the condition is true. The various conditions are defined in Table 3-2. The
instruction encoding is shown in Figure 3-18.
Block data transfer instructions are used to load (LDM) or store (STM) any subset of the currently visible
registers. They support all possible stacking modes, maintaining full or empty stacks which can grow up or down
memory, and are very efficient instructions for saving or restoring context, or for moving large blocks of data
around main memory.
THE REGISTER LIST
The instruction can cause the transfer of any registers in the current bank (and non-user mode programs can also
transfer to and from the user bank, see below). The register list is a 16 bit field in the instruction, with each bit
corresponding to a register. A 1 in bit 0 of the register field will cause R0 to be transferred, a 0 will cause it not to
be transferred; similarly bit 1 controls the transfer of R1, and so on.
Any subset of the registers, or all the registers, may be specified. The only restriction is that the register list
should not be empty.
Whenever R15 is stored to memory the stored value is the address of the STM instruction plus 12.
31
28 27
25 24 23 22 21 20 19
16 15
0
100
P U S W L
Rn
Register list
Cond
[19:16] Base Register
[20] Load/Store Bit
0 = Store to memory
1 = Load from memory
[21] Write-back Bit
0 = No write-back
1 = Write address into base
[22] PSR & Force User Bit
0 = Do not load PSR or user mode
1 = Load PSR or force user mode
[23] Up/Down Bit
0 = Down: subtract offset from base
1 = Up: add offset to base
[24] Pre/Post Indexing Bit
0 = Post: add offset after transfer
1 = Pre: add offset bofore transfer
[31:28] Condition Field
Figure 3-18. Block Data Transfer Instructions
3-40
S3C4510B
INSTRUCTION SET
ADDRESSING MODES
The transfer addresses are determined by the contents of the base register (Rn), the pre/post bit (P) and the up/
down bit (U). The registers are transferred in the order lowest to highest, so R15 (if in the list) will always be
transferred last. The lowest register also gets transferred to/from the lowest memory address. By way of
illustration, consider the transfer of R1, R5 and R7 in the case where Rn = 0x1000 and write back of the modified
base is required (W = 1). Figure 3.19-22 show the sequence of register transfers, the addresses used, and the
value of Rn after the instruction has completed.
In all cases, had write back of the modified base not been required (W = 0), Rn would have retained its initial
value of 0x1000 unless it was also in the transfer list of a load multiple register instruction, when it would have
been overwritten with the loaded value.
ADDRESS ALIGNMENT
The address should normally be a word aligned quantity and non-word aligned addresses do not affect the
instruction. However, the bottom 2 bits of the address will appear on A[1:0] and might be interpreted by the
memory system.
0x100C
0x1000
0x0FF4
0x100C
0x1000
0x0FF4
0x100C
0x1000
0x0FF4
0x100C
0x1000
0x0FF4
Rn
R1
2
1
Rn
R7
R5
R1
R5
R1
3
4
Figure 3-19. Post-Increment Addressing
3-41
INSTRUCTION SET
S3C4510B
0x100C
0x1000
0x0FF4
0x100C
0x1000
0x0FF4
0x100C
0x1000
0x0FF4
0x100C
0x1000
0x0FF4
R1
Rn
1
2
Rn
R7
R5
R1
R5
R1
3
4
Figure 3-20. Pre-Increment Addressing
0x100C
0x1000
0x100C
0x1000
0x0FF4
0x100C
0x1000
0x0FF4
Rn
R1
0x0FF4
1
2
0x100C
0x1000
0x0FF4
R7
R5
R1
R5
R1
Rn
3
4
Figure 3-21. Post-Decrement Addressing
3-42
S3C4510B
INSTRUCTION SET
0x100C
0x1000
0x0FF4
0x100C
0x1000
0x0FF4
0x100C
0x1000
0x0FF4
0x100C
0x1000
0x0FF4
Rn
R1
2
1
R7
R5
R1
4
R5
R1
3
Rn
Figure 3-22. Pre-Decrement Addressing
USE OF THE S BIT
When the S bit is set in a LDM/STM instruction its meaning depends on whether or not R15 is in the transfer list
and on the type of instruction. The S bit should only be set if the instruction is to execute in a privileged mode.
LDM with R15 in Transfer List and S Bit Set (Mode Changes)
If the instruction is a LDM then SPSR_<mode> is transferred to CPSR at the same time as R15 is loaded.
STM with R15 in Transfer List and S Bit Set (User Bank Transfer)
The registers transferred are taken from the user bank rather than the bank corresponding to the current mode.
This is useful for saving the user state on process switches. Base write-back should not be used when this
mechanism is employed.
R15 not in List and S Bit Set (User Bank Transfer)
For both LDM and STM instructions, the user bank registers are transferred rather than the register bank
corresponding to the current mode. This is useful for saving the user state on process switches. Base write-back
should not be used when this mechanism is employed.
When the instruction is LDM, care must be taken not to read from a banked register during the following cycle
(inserting a dummy instruction such as MOV R0, R0 after the LDM will ensure safety).
USE OF R15 AS THE BASE
R15 should not be used as the base register in any LDM or STM instruction.
3-43
INSTRUCTION SET
S3C4510B
INCLUSION OF THE BASE IN THE REGISTER LIST
When write-back is specified, the base is written back at the end of the second cycle of the instruction. During a
STM, the first register is written out at the start of the second cycle. A STM which includes storing the base, with
the base as the first register to be stored, will therefore store the unchanged value, whereas with the base second
or later in the transfer order, will store the modified value. A LDM will always overwrite the updated base if the
base is in the list.
DATA ABORTS
Some legal addresses may be unacceptable to a memory management system, and the memory manager can
indicate a problem with an address by taking the abort signal high. This can happen on any transfer during a
multiple register load or store, and must be recoverable if ARM7TDMI is to be used in a virtual memory system.
Aborts during STM Instructions
If the abort occurs during a store multiple instruction, ARM7TDMI takes little action until the instruction
completes, whereupon it enters the data abort trap. The memory manager is responsible for preventing
erroneous writes to the memory. The only change to the internal state of the processor will be the modification of
the base register if write-back was specified, and this must be reversed by software (and the cause of the abort
resolved) before the instruction may be retried.
Aborts during LDM Instructions
When ARM7TDMI detects a data abort during a load multiple instruction, it modifies the operation of the
instruction to ensure that recovery is possible.
— Overwriting of registers stops when the abort happens. The aborting load will not take place but earlier ones
may have overwritten registers. The PC is always the last register to be written and so will always be
preserved.
— The base register is restored, to its modified value if write-back was requested. This ensures recoverability in
the case where the base register is also in the transfer list, and may have been overwritten before the abort
occurred.
The data abort trap is taken when the load multiple has completed, and the system software must undo any base
modification (and resolve the cause of the abort) before restarting the instruction.
INSTRUCTION CYCLE TIMES
Normal LDM instructions take nS + 1N + 1I and LDM PC takes (n+1)S + 2N + 1I incremental cycles, where S,N
and I are defined as sequential (S-cycle), non-sequential (N-cycle), and internal (I-cycle), respectively. STM
instructions take (n-1)S + 2N incremental cycles to execute, where n is the number of words transferred.
3-44
S3C4510B
INSTRUCTION SET
ASSEMBLER SYNTAX
<LDM|STM>{cond}<FD|ED|FA|EA|IA|IB|DA|DB> Rn{!},<Rlist>{^}
where:
{cond}
Rn
Two character condition mnemonic. See Table 3-2.
An expression evaluating to a valid register number
<Rlist>
{!}
A list of registers and register ranges enclosed in {} (e.g. {R0, R2–R7, R10}).
If present requests write-back (W = 1), otherwise W = 0.
{^}
If present set S bit to load the CPSR along with the PC, or force transfer of user
bank when in privileged mode.
Addressing Mode Names
There are different assembler mnemonics for each of the addressing modes, depending on whether the
instruction is being used to support stacks or for other purposes. The equivalence between the names and the
values of the bits in the instruction are shown in the following table 3-6.
Table 3-6. Addressing Mode Names
Name
Pre-Increment load
Stack
Other
LDMIB
LDMIA
LDMDB
LDMDA
STMIB
STMIA
STMDB
STMDA
L Bit
P Bit
U Bit
LDMED
LDMFD
LDMEA
LDMFA
STMFA
STMEA
STMFD
STMED
1
1
1
1
0
0
0
0
1
0
1
0
1
0
1
0
1
1
0
0
1
1
0
0
Post-Increment load
Pre-Decrement load
Post-Decrement load
Pre-Increment store
Post-Increment store
Pre-Decrement store
Post-Decrement store
FD, ED, FA, EA define pre/post indexing and the up/down bit by reference to the form of stack required. The F
and E refer to a “full” or "empty” stack, i.e. whether a pre-index has to be done (full) before storing to the stack.
The A and D refer to whether the stack is ascending or descending. If ascending, a STM will go up and LDM
down, if descending, vice-versa.
IA, IB, DA, DB allow control when LDM/STM are not being used for stacks and simply mean increment after,
increment before, decrement after, decrement before.
3-45
INSTRUCTION SET
Examples
S3C4510B
LDMFD
SP!,{R0,R1,R2}
R0,{R0-R15}
SP!,{R15}
; Unstack 3 registers.
; Save all registers.
STMIA
LDMFD
LDMFD
; R15 <- (SP), CPSR unchanged.
; R15 <- (SP), CPSR <- SPSR_mode
; (allowed only in privileged modes).
; Save user mode regs on stack
; (allowed only in privileged modes).
SP!,{R15}^
STMFD
R13,{R0-R14}^
These instructions may be used to save state on subroutine entry, and restore it efficiently on return to the calling
routine:
STMED
SP!,{R0–R3,R14}
; Save R0 to R3 to use as workspace
; and R14 for returning.
BL
LDMED
somewhere
SP!,{R0–R3,R15}
; This nested call will overwrite R14
; Restore workspace and return.
3-46
S3C4510B
INSTRUCTION SET
SINGLE DATA SWAP (SWP)
31
28 27
23 22 21 20 19
00
16 15
12 11
8
7
4
3
0
00010
B
Rn
Rd
0000
1001
Rm
Cond
[3:0] Source Register
[15:12] Destination Register
[19:16] Base Register
[22] Byte/Word Bit
0 = Swap word quantity
1 = Swap word quantity
[31:28] Condition Field
Figure 3-23. Swap Instruction
The instruction is only executed if the condition is true. The various conditions are defined in Table 3-2. The
instruction encoding is shown in Figure 3-23.
The data swap instruction is used to swap a byte or word quantity between a register and external memory. This
instruction is implemented as a memory read followed by a memory write which are “locked” together (the
processor cannot be interrupted until both operations have completed, and the memory manager is warned to
treat them as inseparable). This class of instruction is particularly useful for implementing software semaphores.
The swap address is determined by the contents of the base register (Rn). The processor first reads the contents
of the swap address. Then it writes the contents of the source register (Rm) to the swap address, and stores the
old memory contents in the destination register (Rd). The same register may be specified as both the source and
destination.
The lock output goes HIGH for the duration of the read and write operations to signal to the external memory
manager that they are locked together, and should be allowed to complete without interruption. This is important
in multi-processor systems where the swap instruction is the only indivisible instruction which may be used to
implement semaphores; control of the memory must not be removed from a processor while it is performing a
locked operation.
BYTES AND WORDS
This instruction class may be used to swap a byte (B = 1) or a word (B = 0) between an ARM7TDMI register and
memory. The SWP instruction is implemented as a LDR followed by a STR and the action of these is as
described in the section on single data transfers. In particular, the description of Big and Little Endian
configuration applies to the SWP instruction.
USE OF R15
Do not use R15 as an operand (Rd, Rn or Rs) in a SWP instruction.
3-47
INSTRUCTION SET
DATA ABORTS
S3C4510B
If the address used for the swap is unacceptable to a memory management system, the memory manager can
flag the problem by driving ABORT HIGH. This can happen on either the read or the write cycle (or both), and in
either case, the data abort trap will be taken. It is up to the system software to resolve the cause of the problem,
then the instruction can be restarted and the original program continued.
INSTRUCTION CYCLE TIMES
Swap instructions take 1S + 2N +1I incremental cycles to execute, where S, N and I are defined as squential (S-
cycle), non-sequential, and internal (I-cycle), respectively.
ASSEMBLER SYNTAX
<SWP>{cond}{B} Rd,Rm,[Rn]
{cond}
{B}
Two-character condition mnemonic. See Table 3-2.
If B is present then byte transfer, otherwise word transfer
Expressions evaluating to valid register numbers
Rd,Rm,Rn
Examples
SWP
R0,R1,[R2]
R2,R3,[R4]
R0,R0,[R1]
; Load R0 with the word addressed by R2, and
; store R1 at R2.
; Load R2 with the byte addressed by R4, and
; store bits 0 to 7 of R3 at R4.
; Conditionally swap the contents of the
; word addressed by R1 with R0.
SWPB
SWPEQ
3-48
S3C4510B
INSTRUCTION SET
SOFTWARE INTERRUPT (SWI)
The instruction is only executed if the condition is true. The various conditions are defined in Table 3-2. The
instruction encoding is shown in Figure 3-24, below
31
28 27
24 23
0
1111
Cond
Comment Field (Ignored by Processor)
[31:28] Condition Field
Figure 3-24. Software Interrupt Instruction
The software interrupt instruction is used to enter supervisor mode in a controlled manner. The instruction causes
the software interrupt trap to be taken, which effects the mode change. The PC is then forced to a fixed value
(0x08) and the CPSR is saved in SPSR_svc. If the SWI vector address is suitably protected (by external memory
management hardware) from modification by the user, a fully protected operating system may be constructed.
RETURN FROM THE SUPERVISOR
The PC is saved in R14_svc upon entering the software interrupt trap, with the PC adjusted to point to the word
after the SWI instruction. MOVS PC,R14_svc will return to the calling program and restore the CPSR.
Note that the link mechanism is not re-entrant, so if the supervisor code wishes to use software interrupts within
itself it must first save a copy of the return address and SPSR.
COMMENT FIELD
The bottom 24 bits of the instruction are ignored by the processor, and may be used to communicate information
to the supervisor code. For instance, the supervisor may look at this field and use it to index into an array of entry
points for routines which perform the various supervisor functions.
INSTRUCTION CYCLE TIMES
Software interrupt instructions take 2S + 1N incremental cycles to execute, where S and N are defined as
squential (S-cycle) and non-squential (N-cycle).
3-49
INSTRUCTION SET
S3C4510B
ASSEMBLER SYNTAX
SWI{cond} <expression>
{cond}
Two character condition mnemonic, Table 3-2.
Evaluated and placed in the comment field (which is ignored by ARM7TDMI).
<expression>
Examples
SWI
SWI
SWINE
ReadC
WriteI+ “k”
0
; Get next character from read stream.
; Output a “k” to the write stream.
; Conditionally call supervisor with 0 in comment field.
Supervisor code
The previous examples assume that suitable supervisor code exists, for instance:
0x08 B Supervisor
EntryTable
DCD ZeroRtn
DCD ReadCRtn
DCD WriteIRtn
. . .
; SWI entry point
; Addresses of supervisor routines
Zero
EQU 0
ReadC
WriteI
EQU 256
EQU 512
Supervisor
; SWI has routine required in bits 8-23 and data (if any) in
; bits 0-7. Assumes R13_svc points to a suitable stack
; Save work registers and return address.
; Get SWI instruction.
STMFD
LDR
R13,{R0-R2,R14}
R0,[R14,#-4]
BIC
MOV
R0,R0,#0xFF000000
R1,R0,LSR#8
; Clear top 8 bits.
; Get routine offset.
ADR
LDR
R2,EntryTable
R15,[R2,R1,LSL#2]
; Get start address of entry table.
; Branch to appropriate routine.
WriteIRtn
. . . . . .
LDMFD
; Enter with character in R0 bits 0-7.
R13,{R0-R2,R15}^
; Restore workspace and return,
; restoring processor mode and flags.
3-50
S3C4510B
INSTRUCTION SET
COPROCESSOR DATA OPERATIONS (CDP)
The instruction is only executed if the condition is true. The various conditions are defined in Table 3-2. The
instruction encoding is shown in Figure 3-25.
This class of instruction is used to tell a coprocessor to perform some internal operation. No result is
communicated back to ARM7TDMI, and it will not wait for the operation to complete. The coprocessor could
contain a queue of such instructions awaiting execution, and their execution can overlap other activity, allowing
the coprocessor and ARM7TDMI to perform independent tasks in parallel.
COPROCESSOR INSTRUCTIONS
The KS32C6200, unlike some other ARM-based processors, does not have an external coprocessor interface. It
does not have a on-chip coprocessor also.
So then all coprocessor instructions will cause the undefined instruction trap to be taken on the KS32C6200.
These coprocessor instructions can be emulated by the undefined trap handler. Even though external
coprocessor can not be connected to the KS32C6200, the coprocessor instructions are still described here in full
for completeness. (Remember that any external coprocessor described in this section is a software emulation.)
31
28 27
24 23
20 19
16 15
12 11
8
7
5
4
3
0
0
Cond
1110
CP Opc
CRn
CRd
Cp#
Cp
CRm
[3:0] Coprocessor operand register
[7:5] Coprocessor information
[11:8] Coprocessor number
[15:12] Coprocessor destination register
[19:16] Coprocessor operand register
[23:20] Coprocessor operation code
[31:28] Condition Field
Figure 3-25. Coprocessor Data Operation Instruction
THE COPROCESSOR FIELDS
Only bit 4 and bits 24 to 31 are significant to ARM7TDMI. The remaining bits are used by coprocessors. The
above field names are used by convention, and particular coprocessors may redefine the use of all fields except
CP# as appropriate. The CP# field is used to contain an identifying number (in the range 0 to 15) for each
coprocessor, and a coprocessor will ignore any instruction which does not contain its number in the CP# field.
The conventional interpretation of the instruction is that the coprocessor should perform an operation specified in
the CP Opc field (and possibly in the CP field) on the contents of CRn and CRm, and place the result in CRd.
3-51
INSTRUCTION SET
S3C4510B
INSTRUCTION CYCLE TIMES
Coprocessor data operations take 1S + bI incremental cycles to execute, where b is the number of cycles spent
in the coprocessor busy-wait loop.
S and I are defined as sequential (S-cycle) and internal (I-cycle).
ASSEMBLER SYNTAX
CDP{cond} p#,<expression1>,cd,cn,cm{,<expression2>}
{cond}
Two character condition mnemonic. See Table 3-2.
The unique number of the required coprocessor
Evaluated to a constant and placed in the CP Opc field
p#
<expression1>
cd, cn and cm
Evaluate to the valid coprocessor register numbers CRd, CRn and CRm
respectively
<expression2>
Where present is evaluated to a constant and placed in the CP field
Examples
CDP
CDPEQ
p1,10,c1,c2,c3
p2,5,c1,c2,c3,2
; Request coproc 1 to do operation 10
; on CR2 and CR3, and put the result in CR1.
; If Z flag is set request coproc 2 to do operation 5 (type 2)
; on CR2 and CR3, and put the result in CR1.
3-52
S3C4510B
INSTRUCTION SET
COPROCESSOR DATA TRANSFERS (LDC, STC)
The instruction is only executed if the condition is true. The various conditions are defined in Table 3-2. The
instruction encoding is shown in Figure 3-26.
This class of instruction is used to load (LDC) or store (STC) a subset of a coprocessor's registers directly to
memory. ARM7TDMI is responsible for supplying the memory address, and the coprocessor supplies or accepts
the data and controls the number of words transferred.
31
28 27
25 24 23 22 21 20 19
16 15
12 11
8
7
0
110
P U N W L
Rn
CRd
CP#
Offset
Cond
[7:0] Unsigned 8 Bit Immediate Offset
[11:8] Coprocessor Number
[15:12] Coprocessor Source/Destination Register
[19:16] Base Register
[20] Load/Store Bit
0 = Store to memory
1 = Load from memory
[21] Write-back Bit
0 = No write-back
1 = Write address into base
[22] Transfer Length
[23] Up/Down Bit
0 = Down: subtract offset from base
1 = Up: add offset to base
[24] Pre/Post Indexing Bit
0 = Post: add offset after transfer
1 = Pre: add offset bofore transfer
[31:28] Condition Field
Figure 3-26. Coprocessor Data Transfer Instructions
THE COPROCESSOR FIELDS
The CP# field is used to identify the coprocessor which is required to supply or accept the data, and a
coprocessor will only respond if its number matches the contents of this field.
The CRd field and the N bit contain information for the coprocessor which may be interpreted in different ways by
different coprocessors, but by convention CRd is the register to be transferred (or the first register where more
than one is to be transferred), and the N bit is used to choose one of two transfer length options. For instance N =
0 could select the transfer of a single register, and N = 1 could select the transfer of all the registers for context
switching.
3-53
INSTRUCTION SET
S3C4510B
ADDRESSING MODES
ARM7TDMI is responsible for providing the address used by the memory system for the transfer, and the
addressing modes available are a subset of those used in single data transfer instructions. Note, however, that
the immediate offsets are 8 bits wide and specify word offsets for coprocessor data transfers, whereas they are
12 bits wide and specify byte offsets for single data transfers.
The 8 bit unsigned immediate offset is shifted left 2 bits and either added to (U = 1) or subtracted from (U = 0)
the base register (Rn); this calculation may be performed either before (P = 1) or after (P = 0) the base is used as
the transfer address. The modified base value may be overwritten back into the base register (if W = 1), or the
old value of the base may be preserved (W = 0). Note that post-indexed addressing modes require explicit
setting of the W bit, unlike LDR and STR which always write-back when post-indexed.
The value of the base register, modified by the offset in a pre-indexed instruction, is used as the address for the
transfer of the first word. The second word (if more than one is transferred) will go to or come from an address
one word (4 bytes) higher than the first transfer, and the address will be incremented by one word for each
subsequent transfer.
ADDRESS ALIGNMENT
The base address should normally be a word aligned quantity. The bottom 2 bits of the address will appear on
A[1:0] and might be interpreted by the memory system.
USE OF R15
If Rn is R15, the value used will be the address of the instruction plus 8 bytes. Base write-back to R15 must not
be specified.
DATA ABORTS
If the address is legal but the memory manager generates an abort, the data trap will be taken. The write-back of
the modified base will take place, but all other processor state will be preserved. The coprocessor is partly
responsible for ensuring that the data transfer can be restarted after the cause of the abort has been resolved,
and must ensure that any subsequent actions it undertakes can be repeated when the instruction is retried.
INSTRUCTION CYCLE TIMES
Coprocessor data transfer instructions take (n-1)S + 2N + bI incremental cycles to execute, where:
The number of words transferred.
n
b
The number of cycles spent in the coprocessor busy-wait loop.
S, N and I are defined as sequential (S-cycle), non-sequential (N-cycle), and internal (I-cycle), respectively.
3-54
S3C4510B
INSTRUCTION SET
ASSEMBLER SYNTAX
<LDC|STC>{cond}{L} p#,cd,<Address>
LDC
STC
{L}
Load from memory to coprocessor
Store from coprocessor to memory
When present perform long transfer (N = 1), otherwise perform short transfer
(N = 0)
{cond}
Two character condition mnemonic. See Table 3-2.
The unique number of the required coprocessor
p#
cd
An expression evaluating to a valid coprocessor register number that is placed in
the CRd field
<Address> can be:
1
An expression which generates an address:
The assembler will attempt to generate an instruction using the PC as a base and a
corrected immediate offset to address the location given by evaluating the
expression. This will be a PC relative, pre-indexed address. If the address is out of
range, an error will be generated
2
A pre-indexed addressing specification:
[Rn]
offset of zero
[Rn,<#expression>]{!}
offset of <expression> bytes
A post-indexed addressing specification:
Rn],<#expression
{!}
offset of <expression> bytes
write back the base register (set the W bit) if! is
present
Rn
is an expression evaluating to a valid
ARM7TDMI register number.
NOTE
If Rn is R15, the assembler will subtract 8 from the offset value to allow for ARM7TDMI pipelining.
Examples
LDC
p1,c2,table
; Load c2 of coproc 1 from address
; table, using a PC relative address.
STCEQL
p2,c3,[R5,#24]!
; Conditionally store c3 of coproc 2
; into an address 24 bytes up from R5,
; write this address back to R5, and use
; long transfer option (probably to store multiple words).
NOTE
Although the address offset is expressed in bytes, the instruction offset field is in words. The assembler
will adjust the offset appropriately.
3-55
INSTRUCTION SET
S3C4510B
COPROCESSOR REGISTER TRANSFERS (MRC, MCR)
The instruction is only executed if the condition is true. The various conditions are defined in Table 3-2.. The
instruction encoding is shown in Figure 3-27.
This class of instruction is used to communicate information directly between ARM7TDMI and a coprocessor. An
example of a coprocessor to ARM7TDMI register transfer (MRC) instruction would be a FIX of a floating point
value held in a coprocessor, where the floating point number is converted into a 32 bit integer within the
coprocessor, and the result is then transferred to ARM7TDMI register. A FLOAT of a 32 bit value in ARM7TDMI
register into a floating point value within the coprocessor illustrates the use of ARM7TDMI register to coprocessor
transfer (MCR).
An important use of this instruction is to communicate control information directly from the coprocessor into the
ARM7TDMI CPSR flags. As an example, the result of a comparison of two floating point values within a
coprocessor can be moved to the CPSR to control the subsequent flow of execution.
31
28 27
24 23
21 20 19
16 15
12 11
8
7
5
4
3
0
1110
CP Opc L
CRn
Rd
CP#
CP
1
CRm
Cond
[3:0] Coprocessor Operand Register
[7:5] Coprocessor Information
[11:8] Coprocessor Number
[15:12] ARM source/Destination Register
[19:16] Coprocessor Source/Destination Register
[20] Load/Store Bit
0 = Store to coprocessor
1 = Load from coprocessor
[21] Coprocessor Operation Mode
[31:28] Condition Field
Figure 3-27. Coprocessor Register Transfer Instructions
THE COPROCESSOR FIELDS
The CP# field is used, as for all coprocessor instructions, to specify which coprocessor is being called upon.
The CP Opc, CRn, CP and CRm fields are used only by the coprocessor, and the interpretation presented here is
derived from convention only. Other interpretations are allowed where the coprocessor functionality is
incompatible with this one. The conventional interpretation is that the CP Opc and CP fields specify the operation
the coprocessor is required to perform, CRn is the coprocessor register which is the source or destination of the
transferred information, and CRm is a second coprocessor register which may be involved in some way which
depends on the particular operation specified.
3-56
S3C4510B
INSTRUCTION SET
TRANSFERS TO R15
When a coprocessor register transfer to ARM7TDMI has R15 as the destination, bits 31, 30, 29 and 28 of the
transferred word are copied into the N, Z, C and V flags respectively. The other bits of the transferred word are
ignored, and the PC and other CPSR bits are unaffected by the transfer.
TRANSFERS FROM R15
A coprocessor register transfer from ARM7TDMI with R15 as the source register will store the PC+ 12.
INSTRUCTION CYCLE TIMES
MRC instructions take 1S + (b+1)I +1C incremental cycles to execute, where S, I and C are defined as sequential
(S-cycle), internal (I-cycle), and coprocessor register transfer (C-cycle), respectively. MCR instructions take 1S +
bI +1C incremental cycles to execute, where b is the number of cycles spent in the coprocessor busy-wait loop.
ASSEMBLER SYNTAX
<MCR|MRC>{cond} p#,<expression1>,Rd,cn,cm{,<expression2>}
MRC
Move from coprocessor to ARM7TDMI register (L = 1)
Move from ARM7TDMI register to coprocessor (L = 0)
Two character condition mnemonic. See Table 3-2.
The unique number of the required coprocessor
MCR
{cond}
p#
<expression1>
Rd
Evaluated to a constant and placed in the CP Opc field
An expression evaluating to a valid ARM7TDMI register number
cn and cm
Expressions evaluating to the valid coprocessor register numbers CRn and CRm
respectively
<expression2>
Where present is evaluated to a constant and placed in the CP field
Examples
MRC
p2,5,R3,c5,c6
; Request coproc 2 to perform operation 5
; on c5 and c6, and transfer the (single
; 32-bit word) result back to R3.
MCR
p6,0,R4,c5,c6
; Request coproc 6 to perform operation 0
; on R4 and place the result in c6.
MRCEQ
p3,9,R3,c5,c6,2
; Conditionally request coproc 3 to
; perform operation 9 (type 2) on c5 and
; c6, and transfer the result back to R3.
3-57
INSTRUCTION SET
S3C4510B
UNDEFINED INSTRUCTION
The instruction is only executed if the condition is true. The various conditions are defined in Table 3-2. The
instruction format is shown in Figure 3-28.
31
28 27
25 24
5
4
3
0
xxxxxxxxxxxxxxxxxxxx
xxxx
011
1
Cond
Figure 3-28. Undefined Instruction
If the condition is true, the undefined instruction trap will be taken.
Note that the undefined instruction mechanism involves offering this instruction to any coprocessors which may
be present, and all coprocessors must refuse to accept it by driving CPA and CPB HIGH.
INSTRUCTION CYCLE TIMES
This instruction takes 2S + 1I + 1N cycles, where S, N and I are defined as sequential (S-cycle), non-sequential
(N-cycle), and internal (I-cycle).
ASSEMBLER SYNTAX
The assembler has no mnemonics for generating this instruction. If it is adopted in the future for some specified
use, suitable mnemonics will be added to the assembler. Until such time, this instruction must not be used.
3-58
S3C4510B
INSTRUCTION SET
INSTRUCTION SET EXAMPLES
The following examples show ways in which the basic ARM7TDMI instructions can combine to give efficient
code. None of these methods saves a great deal of execution time (although they may save some), mostly they
just save code.
USING THE CONDITIONAL INSTRUCTIONS
Using Conditionals for Logical OR
CMP
BEQ
CMP
BEQ
Rn,#p
Label
Rm,#q
Label
; If Rn=p OR Rm=q THEN GOTO Label.
This can be replaced by
CMP
CMPNE
BEQ
Rn,#p
Rm,#q
Label
; If condition not satisfied try other test.
Absolute Value
TEQ
Rn,#0
; Test sign
RSBMI
Rn,Rn,#0
; and 2's complement if necessary.
Multiplication by 4, 5 or 6 (Run Time)
MOV
CMP
Rc,Ra,LSL#2
Rb,#5
; Multiply by 4,
; Test value,
ADDCS
ADDHI
Rc,Rc,Ra
Rc,Rc,Ra
; Complete multiply by 5,
; Complete multiply by 6.
Combining Discrete and Range Tests
TEQ
CMPNE
MOVLS
Rc,#127
Rc,# ” ”-1
Rc,# “”
; Discrete test,
; Range test
; IF Rc<= ”” OR Rc=ASCII(127)
; THEN Rc:= ” ”
3-59
INSTRUCTION SET
S3C4510B
Division and Remainder
A number of divide routines for specific applications are provided in source form as part of the ANSI C library
provided with the ARM Cross development toolkit, available from your supplier. A short general purpose divide
routine follows.
; Enter with numbers in Ra and Rb.
MOV
Rcnt,#1
; Bit to control the division.
Div1
Div2
CMP
Rb,#0x80000000
Rb,Ra
Rb,Rb,ASL#1
Rcnt,Rcnt,ASL#1
Div1
; Move Rb until greater than Ra.
CMPCC
MOVCC
MOVCC
BCC
MOV
CMP
SUBCS
ADDCS
MOVS
MOVNE
BNE
Rc,#0
Ra,Rb
; Test for possible subtraction.
; Subtract if ok,
; Put relevant bit into result
; Shift control bit
; Halve unless finished.
; Divide result in Rc, remainder in Ra.
Ra,Ra,Rb
Rc,Rc,Rcnt
Rcnt,Rcnt,LSR#1
Rb,Rb,LSR#1
Div2
Overflow Detection in the ARM7TDMI
1. Overflow in unsigned multiply with a 32-bit result
UMULL
TEQ
Rd,Rt,Rm,Rn
Rt,#0
; 3 to 6 cycles
; +1 cycle and a register
BNE
overflow
2. Overflow in signed multiply with a 32-bit result
SMULL
TEQ
BNE
Rd,Rt,Rm,Rn
Rt,Rd ASR#31
overflow
; 3 to 6 cycles
; +1 cycle and a register
3. Overflow in unsigned multiply accumulate with a 32 bit result
UMLAL
TEQ
Rd,Rt,Rm,Rn
Rt,#0
; 4 to 7 cycles
; +1 cycle and a register
BNE
overflow
4. Overflow in signed multiply accumulate with a 32 bit result
SMLAL
TEQ
BNE
Rd,Rt,Rm,Rn
Rt,Rd, ASR#31
overflow
; 4 to 7 cycles
; +1 cycle and a register
3-60
S3C4510B
INSTRUCTION SET
5. Overflow in unsigned multiply accumulate with a 64 bit result
UMULL
ADDS
ADC
Rl,Rh,Rm,Rn
Rl,Rl,Ra1
Rh,Rh,Ra2
overflow
; 3 to 6 cycles
; Lower accumulate
; Upper accumulate
; 1 cycle and 2 registers
BCS
6. Overflow in signed multiply accumulate with a 64 bit result
SMULL
ADDS
ADC
Rl,Rh,Rm,Rn
Rl,Rl,Ra1
Rh,Rh,Ra2
overflow
; 3 to 6 cycles
; Lower accumulate
; Upper accumulate
; 1 cycle and 2 registers
BVS
NOTE
Overflow checking is not applicable to unsigned and signed multiplies with a 64-bit result, since overflow
does not occur in such calculations.
PSEUDO-RANDOM BINARY SEQUENCE GENERATOR
It is often necessary to generate (pseudo-) random numbers and the most efficient algorithms are based on shift
generators with exclusive-OR feedback rather like a cyclic redundancy check generator. Unfortunately the
sequence of a 32 bit generator needs more than one feedback tap to be maximal length (i.e. 2^32-1 cycles
before repetition), so this example uses a 33 bit register with taps at bits 33 and 20. The basic algorithm is
newbit: = bit 33 eor bit 20, shift left the 33 bit number and put in newbit at the bottom; this operation is performed
for all the newbits needed (i.e. 32 bits). The entire operation can be done in 5 S cycles:
; Enter with seed in Ra (32 bits),
; Rb (1 bit in Rb lsb), uses Rc.
TST
Rb,Rb,LSR#1
Rc,Ra,RRX
Rb,Rb,Rb
Rc,Rc,Ra,LSL#12
Ra,Rc,Rc,LSR#20
; Top bit into carry
; 33 bit rotate right
; Carry into lsb of Rb
; (involved!)
MOVS
ADC
EOR
EOR
; (similarly involved!) new seed in Ra, Rb as before
MULTIPLICATION BY CONSTANT USING THE BARREL SHIFTER
Multiplication by 2^n (1,2,4,8,16,32..)
MOV
Ra, Rb, LSL #n
Multiplication by 2^n+1 (3,5,9,17..)
ADD
Ra,Ra,Ra,LSL #n
Multiplication by 2^n-1 (3,7,15..)
RSB
Ra,Ra,Ra,LSL #n
3-61
INSTRUCTION SET
Multiplication by 6
S3C4510B
ADD
MOV
Ra,Ra,Ra,LSL #1
Ra,Ra,LSL#1
; Multiply by 3
; and then by 2
Multiply by 10 and add in extra number
ADD
ADD
Ra,Ra,Ra,LSL#2
Ra,Rc,Ra,LSL#1
; Multiply by 5
; Multiply by 2 and add in next digit
General recursive method for Rb := Ra*C, C a constant:
1. If C even, say C = 2^n*D, D odd:
D=1:
D<>1:
MOV
MOV Rb,Ra,LSL #n
{Rb := Ra*D}
Rb,Rb,LSL #n
2. If C MOD 4 = 1, say C = 2^n*D+1, D odd, n>1:
D=1:
D<>1:
ADD
ADD Rb,Ra,Ra,LSL #n
{Rb := Ra*D}
Rb,Ra,Rb,LSL #n
3. If C MOD 4 = 3, say C = 2^n*D-1, D odd, n>1:
D=1:
D<>1:
RSB
RSB Rb,Ra,Ra,LSL #n
{Rb := Ra*D}
Rb,Ra,Rb,LSL #n
This is not quite optimal, but close. An example of its non-optimality is multiply by 45 which is done by:
RSB
RSB
ADD
Rb,Ra,Ra,LSL#2
Rb,Ra,Rb,LSL#2
Rb,Ra,Rb,LSL# 2
; Multiply by 3
; Multiply by 4*3-1 = 11
; Multiply by 4*11+1 = 45
rather than by:
ADD
ADD
Rb,Ra,Ra,LSL#3
Rb,Rb,Rb,LSL#2
; Multiply by 9
; Multiply by 5*9 = 45
3-62
S3C4510B
INSTRUCTION SET
LOADING A WORD FROM AN UNKNOWN ALIGNMENT
; Enter with address in Ra (32 bits) uses
; Rb, Rc result in Rd. Note d must be less than c e.g. 0,1
; Get word aligned address
BIC
Rb,Ra,#3
LDMIA
AND
Rb,{Rd,Rc}
Rb,Ra,#3
; Get 64 bits containing answer
; Correction factor in bytes
MOVS
MOVNE
RSBNE
ORRNE
Rb,Rb,LSL#3
Rd,Rd,LSR Rb
Rb,Rb,#32
;
...now in bits and test if aligned
; Produce bottom of result word (if not aligned)
; Get other shift amount
; Combine two halves to get result
Rd,Rd,Rc,LSL Rb
3-63
INSTRUCTION SET
S3C4510B
THUMB INSTRUCTION SET FORMAT
The thumb instruction sets are 16-bit versions of ARM instruction sets (32-bit format). The ARM instructions are
reduced to 16-bit versions, Thumb instructions, at the cost of versatile functions of the ARM instruction sets. The
thumb instructions are decompressed to the ARM instructions by the Thumb decompressor inside the
ARM7TDMI core.
As the Thumb instructions are compressed ARM instructions, the Thumb instructions have the 16-bit format
instructions and have some restrictions. The restrictions by 16-bit format is fully notified for using the Thumb
instructions.
FORMAT SUMMARY
The THUMB instruction set formats are shown in the following figure.
15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
1
2
3
0
0
0
0
0
0
0
0
1
Op
Offset5
Rs
Rs
Rd
Rd
Move Shifted register
Add/subtract
1
1
I
Op Rn/offset3
Rd
Op
Offset8
Move/compare/add/
subtract immediate
4
5
0
0
1
1
0
0
0
0
0
0
0
1
Op
Rs
Rd
ALU operations
Op
Rd
H1 H2
Rs/Hs
Rd/Hd
Hi regiter operations
/branch exchange
PC-relative load
6
7
0
0
1
1
0
0
0
1
1
L
Word8
Rb
B
S
0
Ro
Ro
Rd
Rd
Rd
Rd
Load/store with register
offset
8
9
0
0
1
1
0
1
1
H
L
1
Rb
Rb
Load/store sign-extended
byte/halfword
B
Offset5
Offset5
Load/store with immediate
offset
10
11
12
13
14
15
16
17
18
19
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
1
1
1
1
1
0
0
1
1
1
0
0
0
1
1
0
1
0
1
1
0
1
1
0
1
L
L
Rb
Load/store halfword
SP-relative load/store
Load address
Rd
Rd
0
Word8
Word8
SP
0
0
1
0
S
SWord7
Rlist
Add offset to stack pointer
Push/pop register
L
0
R
L
Rb
Rlist
Multiple load/store
Conditional branch
Software interrupt
Cond
Softset8
Value8
1
0
1
1
1
Offset11
Offset
Unconditional branch
Long branch with link
H
15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
Figure 3-29. THUMB Instruction Set Formats
3-64
S3C4510B
INSTRUCTION SET
OPCODE SUMMARY
The following table summarises the THUMB instruction set. For further information about a particular instruction
please refer to the sections listed in the right-most column.
Table 3-7. THUMB Instruction Set Opcodes
Mnemonic
ADC
Instruction
Lo-Register
Operand
Hi-Register
Operand
Condition
Codes Set
Add with carry
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
–
V
–
–
–
–
–
–
V
–
V
–
–
–
–
–
–
–
–
–
V
–
–
–
–
–
–
–
V
V (1)
V
V
–
ADD
AND
ASR
B
Add
AND
Arithmetic shift right
Unconditional branch
Conditional branch
Bit clear
Bxx
–
BIC
V
–
BL
Branch and link
Branch and exchange
Compare negative
Compare
BX
–
CMN
CMP
EOR
LDMIA
LDR
LDRB
LDRH
LSL
V
V
V
–
EOR
Load multiple
Load word
–
Load byte
–
Load half-word
Logical shift left
Load sign-extended byte
Load sign-extended half-word
Logical shift right
Move register
Multiply
–
V
–
LDSB
LDSH
LSR
MOV
MUL
MVN
NEG
ORR
POP
PUSH
POR
–
V
V (2)
V
V
V
V
–
Move negative register
Negate
OR
Pop registers
Push registers
Rotate right
–
V
3-65
INSTRUCTION SET
Mnemonic
S3C4510B
Table 3-7. THUMB Instruction Set Opcodes (Continued)
Instruction
Lo-Register
Operand
Hi-Register
Operand
Condition
Codes Set
SBC
Subtract with carry
V
V
V
V
V
–
–
–
–
–
–
–
–
–
V
–
–
–
–
–
V
V
STMIA
STR
Store multiple
Store word
Store byte
STRB
STRH
SWI
Store half-word
Software interrupt
Subtract
SUB
V
V
TST
Test bits
NOTES:
1. The condition codes are unaffected by the format 5, 12 and 13 versions of this instruction.
2. The condition codes are unaffected by the format 5 version of this instruction.
3-66
S3C4510B
INSTRUCTION SET
FORMAT 1: MOVE SHIFTED REGISTER
11
10
3
2
15
14
13
12
6
5
0
Offset5
Rs
Rd
0
0
0
Op
[2:0] Destination Register
[5:3] Source Register
[10:6] Immediate Vale
[12:11] Opcode
0 = LSL
1 = LSR
2 = ASR
Figure 3-30. Format 1
OPERATION
These instructions move a shifted value between Lo registers. The THUMB assembler syntax is shown in
Table 3-8.
NOTE
All instructions in this group set the CPSR condition codes.
Table 3-8. Summary of Format 1 Instructions
OP
THUMB Assembler
ARM Equivalent
Action
00
LSL Rd, Rs, #Offset5
MOVS Rd, Rs, LSL #Offset5
Shift Rs left by a 5-bit immediate value and
store the result in Rd.
01
10
LSR Rd, Rs, #Offset5
ASR Rd, Rs, #Offset5
MOVS Rd, Rs, LSR #Offset5 Perform logical shift right on Rs by a 5-bit
immediate value and store the result in Rd.
MOVS Rd, Rs, ASR #Offset5 Perform arithmetic shift right on Rs by a 5-bit
immediate value and store the result in Rd.
INSTRUCTION CYCLE TIMES
All instructions in this format have an equivalent ARM instruction as shown in Table 3-8. The instruction cycle
times for the THUMB instruction are identical to that of the equivalent ARM instruction.
Examples
LSR
R2, R5, #27
; Logical shift right the contents
; of R5 by 27 and store the result in R2.
; Set condition codes on the result.
3-67
INSTRUCTION SET
S3C4510B
FORMAT 2: ADD/SUBTRACT
15
14
13
12
11
10
9
8
6
5
3
2
0
Rn/Offset3
Rs
Rd
0
0
0
1
1
1
Op
[2:0] Destination Register
[5:3] Source Register
[8:6] Register/Immediate Value
[9] Opcode
0 = ADD
1 = SUB
[10] Immediate Flag
0 = Register operand
1 = Immediate oerand
Figure 3-31. Format 2
OPERATION
These instructions allow the contents of a Lo register or a 3-bit immediate value to be added to or subtracted
from a Lo register. The THUMB assembler syntax is shown in Table 3-9.
NOTE
All instructions in this group set the CPSR condition codes.
Table 3-9. Summary of Format 2 Instructions
OP
I
THUMB Assembler
ARM Equivalent
Action
0
0
ADD Rd, Rs, Rn
ADDS Rd, Rs, Rn
Add contents of Rn to contents of Rs.
Place result in Rd.
0
1
1
1
0
1
ADD Rd, Rs, #Offset3 ADDS Rd, Rs, #Offset3 Add 3-bit immediate value to contents of Rs.
Place result in Rd.
SUB Rd, Rs, Rn
SUBS Rd, Rs, Rn
Subtract contents of Rn from contents of Rs.
Place result in Rd.
SUB Rd, Rs, #Offset3 SUBS Rd, Rs, #Offset3 Subtract 3-bit immediate value from contents
of Rs. Place result in Rd.
3-68
S3C4510B
INSTRUCTION SET
INSTRUCTION CYCLE TIMES
All instructions in this format have an equivalent ARM instruction as shown in Table 3-9. The instruction cycle
times for the THUMB instruction are identical to that of the equivalent ARM instruction.
Examples
ADD
SUB
R0, R3, R4
R6, R2, #6
; R0 : = R3 + R4 and set condition codes on the result.
; R6 : = R2 - 6 and set condition codes.
3-69
INSTRUCTION SET
S3C4510B
FORMAT 3: MOVE/COMPARE/ADD/SUBTRACT IMMEDIATE
15
14
13
12
11
10
8
7
0
Rd
Offset8
0
0
0
Op
[7:0] Immediate Value
[10:8] Source/Destination Register
[12:11] Opcode
0 = MOV
1 = CMP
2 = ADD
3 = SUB
Figure 3-32. Format 3
OPERATIONS
The instructions in this group perform operations between a Lo register and an 8-bit immediate value. The
THUMB assembler syntax is shown in Table 3-10.
NOTE
All instructions in this group set the CPSR condition codes.
Table 3-10. Summary of Format 3 Instructions
OP
00
THUMB Assembler
MOV Rd, #Offset8
CMP Rd, #Offset8
ARM Equivalent
MOVS Rd, #Offset8
CMP Rd, #Offset8
Action
Move 8-bit immediate value into Rd.
01
Compare contents of Rd with 8-bit immediate
value.
10
11
ADD Rd, #Offset8
SUB Rd, #Offset8
ADDS Rd, Rd, #Offset8 Add 8-bit immediate value to contents of Rd and
place the result in Rd.
SUBS Rd, Rd, #Offset8 Subtract 8-bit immediate value from contents of
Rd and place the result in Rd.
INSTRUCTION CYCLE TIMES
All instructions in this format have an equivalent ARM instruction as shown in Table 3-10. The instruction cycle
times for the THUMB instruction are identical to that of the equivalent ARM instruction.
Examples
MOV
CMP
ADD
SUB
R0, #128
R2, #62
R1, #255
R6, #145
; R0 : = 128 and set condition codes
; Set condition codes on R2 - 62
; R1 : = R1 + 255 and set condition codes
; R6 : = R6 - 145 and set condition codes
3-70
S3C4510B
INSTRUCTION SET
FORMAT 4: ALU OPERATIONS
11
10
9
3
2
15
14
13
12
6
5
0
Rs
Rd
0
0
0
0
0
0
Op
[2:0] Source/Destination Register
[5:3] Source Register 2
[9:6] Opcode
Figure 3-33. Format 4
OPERATION
The following instructions perform ALU operations on a Lo register pair.
NOTE
All instructions in this group set the CPSR condition codes
Table 3-11. Summary of Format 4 Instructions
OP
THUMB Assembler
ARM Equivalent
ANDS Rd, Rd, Rs
Action
0000 AND Rd, Rs
0001 EOR Rd, Rs
0010 LSL Rd, Rs
0011 LSR Rd, Rs
0100 ASR Rd, Rs
0101 ADC Rd, Rs
0110 SBC Rd, Rs
0111 ROR Rd, Rs
1000 TST Rd, Rs
1001 NEG Rd, Rs
1010 CMP Rd, Rs
1011 CMN Rd, Rs
1100 ORR Rd, Rs
1101 MUL Rd, Rs
1110 BIC Rd, Rs
1111 MVN Rd, Rs
Rd: = Rd AND Rs
Rd: = Rd EOR Rs
Rd : = Rd << Rs
Rd : = Rd >> Rs
Rd : = Rd ASR Rs
EORS Rd, Rd, Rs
MOVS Rd, Rd, LSL Rs
MOVS Rd, Rd, LSR Rs
MOVS Rd, Rd, ASR Rs
ADCS Rd, Rd, Rs
SBCS Rd, Rd, Rs
MOVS Rd, Rd, ROR Rs
TST Rd, Rs
Rd : = Rd + Rs + C-bit
Rd : = Rd - Rs - NOT C-bit
Rd : = Rd ROR Rs
Set condition codes on Rd AND Rs
Rd = - Rs
RSBS Rd, Rs, #0
CMP Rd, Rs
Set condition codes on Rd - Rs
Set condition codes on Rd + Rs
Rd: = Rd OR Rs
CMN Rd, Rs
ORRS Rd, Rd, Rs
MULS Rd, Rs, Rd
BICS Rd, Rd, Rs
MVNS Rd, Rs
Rd: = Rs * Rd
Rd: = Rd AND NOT Rs
Rd: = NOT Rs
3-71
INSTRUCTION SET
S3C4510B
INSTRUCTION CYCLE TIMES
All instructions in this format have an equivalent ARM instruction as shown in Table 3-11. The instruction cycle
times for the THUMB instruction are identical to that of the equivalent ARM instruction.
Examples
EOR
ROR
R3, R4
R1, R0
; R3 : = R3 EOR R4 and set condition codes
; Rotate right R1 by the value in R0, store
; the result in R1 and set condition codes
; Subtract the contents of R3 from zero,
NEG
R5, R3
; store the result in R5. Set condition codes ie R5 = - R3
; Set the condition codes on the result of R2 - R6
; R0 : = R7 * R0 and set condition codes
CMP
MUL
R2, R6
R0, R7
3-72
S3C4510B
INSTRUCTION SET
FORMAT 5: HI-REGISTER OPERATIONS/BRANCH EXCHANGE
11
10
9
8
7
3
2
15
14
13
12
6
5
0
Rs/Hs
Rd/Hd
0
0
0
0
0
0
Op
H1
H2
[2:0] Destination Register
[5:3] Source Register
[6] Hi Operand Flag 2
[7] Hi Operand Flag 1
[9:8] Opcode
Figure 3-34. Format 5
OPERATION
There are four sets of instructions in this group. The first three allow ADD, CMP and MOV operations to be
performed between Lo and Hi registers, or a pair of Hi registers. The fourth, BX, allows a Branch to be performed
which may also be used to switch processor state. The THUMB assembler syntax is shown in Table 3-12.
NOTE
In this group only CMP (Op = 01) sets the CPSR condition codes.
The action of H1 = 0, H2 = 0 for Op = 00 (ADD), Op = 01 (CMP) and Op = 10 (MOV) is undefined, and should
not be used.
3-73
INSTRUCTION SET
OP H1 H2
S3C4510B
Table 3-12. Summary of Format 5 Instructions
THUMB Assembler
ARM Equivalent
Action
00
0
1
ADD Rd, Hs
ADD Rd, Rd, Hs
Add a register in the range 8-15 to a register in
the range 0-7.
00
1
0
ADD Hd, Rs
ADD Hd, Hd, Rs
Add a register in the range 0-7 to a register in
the range 8-15.
00
01
1
0
1
1
ADD Hd, Hs
CMP Rd, Hs
ADD Hd, Hd, Hs
CMP Rd, Hs
Add two registers in the range 8-15.
Compare a register in the range 0-7 with a
register in the range 8-15. Set the condition
code flags on the result.
01
1
0
CMP Hd, Rs
CMP Hd, Rs
Compare a register in the range 8-15 with a
register in the range 0-7. Set the condition
code flags on the result.
01
10
10
00
00
00
1
0
1
0
1
1
1
1
0
1
0
1
CMP Hd, Hs
MOV Rd, Hs
MOV Hd, Rs
MOV Hd, Hs
BX Rs
CMP Hd, Hs
MOV Rd, Hs
MOV Hd, Rs
MOV Hd, Hs
BX Rs
Compare two registers in the range 8-15. Set
the condition code flags on the result.
Move a value from a register in the range 8-15
to a register in the range 0-7.
Move a value from a register in the range 0-7
to a register in the range 8-15.
Move a value between two registers in the
range 8-15.
Perform branch (plus optional state change) to
address in a register in the range 0-7.
BX Hs
BX Hs
Perform branch (plus optional state change) to
address in a register in the range 8-15.
INSTRUCTION CYCLE TIMES
All instructions in this format have an equivalent ARM instruction as shown in Table 3-12. The instruction cycle
times for the THUMB instruction are identical to that of the equivalent ARM instruction.
THE BX INSTRUCTION
BX performs a branch to a routine whose start address is specified in a Lo or Hi register.
Bit 0 of the address determines the processor state on entry to the routine:
Bit 0 = 0
Bit 0 = 1
Causes the processor to enter ARM state.
Causes the processor to enter THUMB state.
NOTE
The action of H1 = 1 for this instruction is undefined, and should not be used.
3-74
S3C4510B
INSTRUCTION SET
Examples
Hi-Register Operations
ADD
R4, R12
MOV
PC, R5
; PC := PC + R5 but don't set the condition codes.CMP
; Set the condition codes on the result of R4 - R12.
; Move R14 (LR) into R15 (PC)
R15, R14
; but don't set the condition codes,
; eg. return from subroutine.
Branch and Exchange
; Switch from THUMB to ARM state.
; Load address of outofTHUMB into R1.
ADR
MOV
BX
R1,outofTHUMB
R11,R1
R11
; Transfer the contents of R11 into the PC.
; Bit 0 of R11 determines whether
; ARM or THUMB state is entered, ie. ARM state here.
...
ALIGN
CODE32
outofTHUMB
; Now processing ARM instructions...
USING R15 AS AN OPERAND
If R15 is used as an operand, the value will be the address of the instruction + 4 with bit 0 cleared. Executing a
BX PC in THUMB state from a non-word aligned address will result in unpredictable execution.
3-75
INSTRUCTION SET
S3C4510B
FORMAT 6: PC-RELATIVE LOAD
11
10
8
7
15
14
13
12
0
Word 8
0
0
0
0
0
Rd
[7:0] Immediate Value
[10:8] Destination Register
Figure 3-35. Format 6
OPERATION
This instruction loads a word from an address specified as a 10-bit immediate offset from the PC. The THUMB
assembler syntax is shown below.
Table 3-13. Summary of PC-Relative Load Instruction
THUMB Assembler
ARM Equivalent
Action
LDR Rd, [PC, #Imm]
LDR Rd, [R15, #Imm]
Add unsigned offset (255 words, 1020 bytes)
in Imm to the current value of the PC. Load
the word from the resulting address into Rd.
NOTE: The value specified by #Imm is a full 10-bit address, but must always be word-aligned (ie with bits 1:0 set to 0),
since the assembler places #Imm >> 2 in field Word 8. The value of the PC will be 4 bytes greater than
the address of this instruction, but bit 1 of the PC is forced to 0 to ensure it is word aligned.
INSTRUCTION CYCLE TIMES
All instructions in this format have an equivalent ARM instruction. The instruction cycle times for the THUMB
instruction are identical to that of the equivalent ARM instruction.
Examples
LDR R3,[PC,#844]
; Load into R3 the word found at the
; address formed by adding 844 to PC.
; bit[1] of PC is forced to zero.
; Note that the THUMB opcode will contain
; 211 as the Word8 value.
3-76
S3C4510B
INSTRUCTION SET
FORMAT 7: LOAD/STORE WITH REGISTER OFFSET
11
10
9
8
3
2
15
14
13
12
6
5
0
Rb
Rd
0
1
0
1
L
B
0
Ro
[2:0] Source/Destination Register
[5:3] Base Register
[8:6] Offset Register
[10] Byte/Word Flag
0 = Transfer word quantity
1 = Transfer byte quantity
[11] Load/Store Flag
0 = Store to memory
1 = Load from memory
Figure 3-36. Format 7
OPERATION
These instructions transfer byte or word values between registers and memory. Memory addresses are pre-
indexed using an offset register in the range 0-7. The THUMB assembler syntax is shown in Table 3-14.
Table 3-14. Summary of Format 7 Instructions
L
B
THUMB Assembler
ARM Equivalent
Action
Pre-indexed word store:
0
0
STR Rd, [Rb, Ro]
STR Rd, [Rb, Ro]
Calculate the target address by adding together the
value in Rb and the value in Ro. Store the contents of
Rd at the address.
0
1
1
1
0
1
STRB Rd, [Rb, Ro]
LDR Rd, [Rb, Ro]
LDRB Rd, [Rb, Ro]
STRB Rd, [Rb, Ro] Pre-indexed byte store:
Calculate the target address by adding together the
value in Rb and the value in Ro. Store the byte value
in Rd at the resulting address.
LDR Rd, [Rb, Ro]
Pre-indexed word load:
Calculate the source address by adding together the
value in Rb and the value in Ro. Load the contents of
the address into Rd.
LDRB Rd, [Rb, Ro] Pre-indexed byte load:
Calculate the source address by adding together the
value in Rb and the value in Ro. Load the byte value
at the resulting address.
3-77
INSTRUCTION SET
S3C4510B
INSTRUCTION CYCLE TIMES
All instructions in this format have an equivalent ARM instruction as shown in Table 3-14. The instruction cycle
times for the THUMB instruction are identical to that of the equivalent ARM instruction.
Examples
STR
R3, [R2,R6]
R2, [R0,R7]
; Store word in R3 at the address
; formed by adding R6 to R2.
; Load into R2 the byte found at
; the address formed by adding R7 to R0.
LDRB
3-78
S3C4510B
INSTRUCTION SET
FORMAT 8: LOAD/STORE SIGN-EXTENDED BYTE/HALF-WORD
11
10
9
8
3
2
15
14
13
12
6
5
0
Rb
Rd
0
1
0
1
H
S
1
Ro
[2:0] Destination Register
[5:3] Base Register
[8:6] Offset Register
[10] Sign-Extended Flag
0 = Operand not sing-extended
1 = Operand sing-extended
[11] H Flag
Figure 3-37. Format 8
OPERATION
These instructions load optionally sign-extended bytes or half-words, and store half-words. The THUMB
assembler syntax is shown below.
Table 3-15. Summary of format 8 instructions
L
B
THUMB Assembler
ARM Equivalent
Action
0
0
STRH Rd, [Rb, Ro]
STRH Rd, [Rb, Ro]
Store half-word:
Add Ro to base address in Rb. Store bits 0–15 of Rd at
the resulting address.
0
1
1
0
LDRH Rd, [Rb, Ro]
LDSB Rd, [Rb, Ro]
LDRH Rd, [Rb, Ro]
Load half-word:
Add Ro to base address in Rb. Load bits 0–15 of Rd from
the resulting address, and set bits 16-31 of Rd to 0.
LDRSB Rd, [Rb, Ro] Load sign-extended byte:
Add Ro to base address in Rb. Load bits 0–7 of Rd from
the resulting address, and set bits 8-31 of Rd to bit 7.
LDRSH Rd, [Rb, Ro] Load sign-extended half-word:
1
1
LDSH Rd, [Rb, Ro]
Add Ro to base address in Rb. Load bits 0–15 of Rd from
the resulting address, and set bits 16-31 of Rd to bit 15.
3-79
INSTRUCTION SET
S3C4510B
INSTRUCTION CYCLE TIMES
All instructions in this format have an equivalent ARM instruction as shown in Table 3-15. The instruction cycle
times for the THUMB instruction are identical to that of the equivalent ARM instruction.
Examples
STRH
LDSB
LDSH
R4, [R3, R0]
R2, [R7, R1]
R3, [R4, R2]
; Store the lower 16 bits of R4 at the
; address formed by adding R0 to R3.
; Load into R2 the sign extended byte
; found at the address formed by adding R1 to R7.
; Load into R3 the sign extended half-word
; found at the address formed by adding R2 to R4.
3-80
S3C4510B
INSTRUCTION SET
FORMAT 9: LOAD/STORE WITH IMMEDIATE OFFSET
11
10
3
2
15
14
13
12
6
5
0
Rb
Rd
0
1
1
B
L
Offset5
[2:0] Source/Destination Register
[5:3] Base Register
[10:6] Offset Register
[11] Load/Store Flag
0 = Store to memory
1 = Load from memory
[12] Byte/Word Flad
0 = Transfer word quantity
1 = Transfer byte quantity
Figure 3-38. Format 9
OPERATION
These instructions transfer byte or word values between registers and memory using an immediate 5 or 7-bit offset. The
THUMB assembler syntax is shown in Table 3-16
Table 3-16. Summary of Format 9 Instructions
L
B
THUMB Assembler
ARM Equivalent
Action
0
0
STR Rd, [Rb, #Imm]
STR Rd, [Rb, #Imm]
Calculate the target address by adding together the
value in Rb and Imm. Store the contents of Rd at
the address.
0
1
1
0
LDR Rd, [Rb, #Imm]
LDR Rd, [Rb, #Imm]
Calculate the source address by adding together the
value in Rb and Imm. Load Rd from the address.
STRB Rd, [Rb, #Imm] STRB Rd, [Rb, #Imm] Calculate the target address by adding together the
value in Rb and Imm. Store the byte value in Rd at
the address.
1
1
LDRB Rd, [Rb, #Imm] LDRB Rd, [Rb, #Imm] Calculate source address by adding together the
value in Rb and Imm. Load the byte value at the
address into Rd.
NOTE: For word accesses (B = 0), the value specified by #Imm is a full 7-bit address, but must be word-aligned
(ie with bits 1:0 set to 0), since the assembler places #Imm >> 2 in the Offset5 field.
3-81
INSTRUCTION SET
S3C4510B
INSTRUCTION CYCLE TIMES
All instructions in this format have an equivalent ARM instruction as shown in Table 3-16. The instruction cycle
times for the THUMB instruction are identical to that of the equivalent ARM instruction.
Examples
LDR
R2, [R5,#116]
R1, [R0,#13]
; Load into R2 the word found at the
; address formed by adding 116 to R5.
; Note that the THUMB opcode will
; contain 29 as the Offset5 value.
; Store the lower 8 bits of R1 at the
; address formed by adding 13 to R0.
; Note that the THUMB opcode will
; contain 13 as the Offset5 value.
STRB
3-82
S3C4510B
INSTRUCTION SET
FORMAT 10: LOAD/STORE HALF-WORD
11
10
3
2
15
14
13
12
6
5
0
Rb
Rd
0
1
0
0
L
Offset5
[2:0] Source/Destination Register
[5:3] Base Register
[10:6] Immediate Value
[11] Load/Store Flag
0 = Store to memory
1 = Load from memory
Figure 3-39. Format 10
OPERATION
These instructions transfer half-word values between a Lo register and memory. Addresses are pre-indexed,
using a 6-bit immediate value. The THUMB assembler syntax is shown in Table 3-17.
Table 3-17. Half-word Data Transfer Instructions
L
THUMB Assembler
ARM Equivalent
Action
0
STRH Rd, [Rb, #Imm] STRH Rd, [Rb, #Imm] Add #Imm to base address in Rb and store bits 0–15 of
Rd at the resulting address.
1
LDRH Rd, [Rb, #Imm] LDRH Rd, [Rb, #Imm] Add #Imm to base address in Rb. Load bits 0–15 from the
resulting address into Rd and set bits 16-31 to zero.
NOTE: #Imm is a full 6-bit address but must be half-word-aligned (ie with bit 0 set to 0),
since the assembler places #Imm >> 1 in the Offset5 field.
INSTRUCTION CYCLE TIMES
All instructions in this format have an equivalent ARM instruction as shown in Table 3-17. The instruction cycle
times for the THUMB instruction are identical to that of the equivalent ARM instruction.
Examples
STRH
LDRH
R6, [R1, #56]
R4, [R7, #4]
; Store the lower 16 bits of R4 at the address formed by
; adding 56 R1. Note that the THUMB opcode will contain
; 28 as the Offset5 value.
; Load into R4 the half-word found at the address formed
by
; adding 4 to R7. Note that the THUMB opcode will
; contain 2 as the Offset5 value.
3-83
INSTRUCTION SET
S3C4510B
FORMAT 11: SP-RELATIVE LOAD/STORE
11
10
15
14
13
12
8
7
0
Word 8
1
0
0
1
L
Rd
[7:0] Immediate Value
[10:8] Destination Register
[11] Load/Store Bit
0 = Store to memory
1 = Load from memory
Figure 3-40. Format 11
OPERATION
The instructions in this group perform an SP-relative load or store. The THUMB assembler syntax is shown in the
following table.
Table 3-18. SP-Relative Load/Store Instructions
L
THUMB Assembler
ARM Equivalent
Action
0
STR Rd, [SP, #Imm]
STR Rd, [R13 #Imm] Add unsigned offset (255 words, 1020 bytes) in Imm to
the current value of the SP (R7). Store the contents of
Rd at the resulting address.
1
LDR Rd, [SP, #Imm]
LDR Rd, [R13 #Imm] Add unsigned offset (255 words, 1020 bytes) in Imm to
the current value of the SP (R7). Load the word from the
resulting address into Rd.
NOTE: The offset supplied in #Imm is a full 10-bit address, but must always be word-aligned (ie bits 1:0 set to 0),
since the assembler places #Imm >> 2 in the Word8 field.
INSTRUCTION CYCLE TIMES
All instructions in this format have an equivalent ARM instruction as shown in Table 3-18. The instruction cycle
times for the THUMB instruction are identical to that of the equivalent ARM instruction.
Examples
STR
R4, [SP,#492]
; Store the contents of R4 at the address
; formed by adding 492 to SP (R13).
; Note that the THUMB opcode will contain
; 123 as the Word8 value.
3-84
S3C4510B
INSTRUCTION SET
FORMAT 12: LOAD ADDRES
11
10
15
14
13
12
8
7
0
Word 8
1
0
1
0
SP
Rd
[7:0] 8-bit Unsigned Constant
[10:8] Destination Register
[11] Source
0 = PC
1 = SP
Figure 3-41. Format 12
OPERATION
These instructions calculate an address by adding an 10-bit constant to either the PC or the SP, and load the
resulting address into a register. The THUMB assembler syntax is shown in the following table.
Table 3-19. Load Address
SP THUMB Assembler
ARM Equivalent
Action
0
ADD Rd, PC, #Imm
ADD Rd, R15, #Imm
Add #Imm to the current value of the program counter
(PC) and load the result into Rd.
1
ADD Rd, SP, #Imm
ADD Rd, R13, #Imm
Add #Imm to the current value of the stack pointer (SP)
and load the result into Rd.
NOTE: The value specified by #Imm is a full 10-bit value, but this must be word-aligned (ie with bits 1:0 set to 0)
since the assembler places #Imm >> 2 in field Word 8.
Where the PC is used as the source register (SP = 0), bit 1 of the PC is always read as 0. The value of the PC
will be 4 bytes greater than the address of the instruction before bit 1 is forced to 0.
The CPSR condition codes are unaffected by these instructions.
3-85
INSTRUCTION SET
S3C4510B
INSTRUCTION CYCLE TIMES
All instructions in this format have an equivalent ARM instruction as shown in Table 3-19. The instruction cycle
times for the THUMB instruction are identical to that of the equivalent ARM instruction.
Examples
ADD
ADD
R2, PC, #572
R6, SP, #212
; R2: = PC + 572, but don't set the
; condition codes. bit[1] of PC is forced to zero.
; Note that the THUMB opcode will
; contain 143 as the Word8 value.
; R6: = SP (R13) + 212, but don't
; set the condition codes.
; Note that the THUMB opcode will
; contain 53 as the Word 8 value.
3-86
S3C4510B
INSTRUCTION SET
FORMAT 13: ADD OFFSET TO STACK POINTER
11
10
9
15
14
13
12
8
7
6
0
SWord 7
1
0
1
1
0
0
0
0
S
[6:0] 7-bit Immediate Value
[7] Sign Flag
0 = Offset is positive
1 = Offset is negative
Figure 3-42. Format 13
OPERATION
This instruction adds a 9-bit signed constant to the stack pointer. The following table shows the THUMB
assembler syntax.
Table 3-20. The ADD SP Instruction
S
0
1
THUMB Assembler
ADD SP, #Imm
ARM Equivalent
Action
ADD R13, R13, #Imm Add #Imm to the stack pointer (SP).
SUB R13, R13, #Imm Add #-Imm to the stack pointer (SP).
ADD SP, #-Imm
NOTE: The offset specified by #Imm can be up to -/+ 508, but must be word-aligned (ie with bits 1:0 set to 0)
since the assembler converts #Imm to an 8-bit sign + magnitude number before placing it in field SWord7.
The condition codes are not set by this instruction.
INSTRUCTION CYCLE TIMES
All instructions in this format have an equivalent ARM instruction as shown in Table 3-20. The instruction cycle
times for the THUMB instruction are identical to that of the equivalent ARM instruction.
Examples
ADD
ADD
SP, #268
SP, #-104
; SP (R13): = SP + 268, but don't set the condition codes.
; Note that the THUMB opcode will
; contain 67 as the Word7 value and S = 0.
; SP (R13): = SP - 104, but don't set the condition codes.
; Note that the THUMB opcode will contain
; 26 as the Word7 value and S = 1.
3-87
INSTRUCTION SET
S3C4510B
FORMAT 14: PUSH/POP REGISTERS
11
10
9
15
14
13
12
8
7
0
Rlist
1
0
1
1
L
1
0
R
[7:0] Register List
[8] PC/LR Bit
0 = Do not store LR/Load PC
1 = Store LR/Load PC
[11] Load/Store Bit
0 = Store to memory
1 = Load from memory
Figure 3-43. Format 14
OPERATION
The instructions in this group allow registers 0-7 and optionally LR to be pushed onto the stack, and registers 0-7
and optionally PC to be popped off the stack. The THUMB assembler syntax is shown in Table 3-21.
NOTE
The stack is always assumed to be full descending.
Table 3-21. PUSH and POP Instructions
L
0
0
B
0
1
THUMB
Assembler
ARM Equivalent
Action
PUSH { Rlist }
STMDB R13!, { Rlist }
Push the registers specified by Rlist onto the stack.
Update the stack pointer.
PUSH { Rlist, LR } STMDB R13!, { Rlist, R14} Push the Link Register and the registers specified
by Rlist (if any) onto the stack. Update the stack
pointer.
1
1
0
1
POP { Rlist }
LDMIA R13!, { Rlist }
Pop values off the stack into the registers specified
by Rlist. Update the stack pointer.
POP { Rlist, PC }
LDMIA R13!, {Rlist, R15} Pop values off the stack and load into the registers
specified by Rlist. Pop the PC off the stack.
Update the stack pointer.
3-88
S3C4510B
INSTRUCTION SET
INSTRUCTION CYCLE TIMES
All instructions in this format have an equivalent ARM instruction as shown in Table 3-21. The instruction cycle
times for the THUMB instruction are identical to that of the equivalent ARM instruction.
Examples
PUSH
POP
{R0–R4,LR}
{R2, R6, PC}
; Store R0, R1, R2, R3, R4 and R14 (LR) at
; the stack pointed to by R13 (SP) and update R13.
; Useful at start of a sub-routine to
; save workspace and return address.
; Load R2, R6 and R15 (PC) from the stack
; pointed to by R13 (SP) and update R13.
; Useful to restore workspace and return from sub-routine.
3-89
INSTRUCTION SET
S3C4510B
FORMAT 15: MULTIPLE LOAD/STORE
11
10
15
14
13
12
8
7
0
Rlist
1
1
0
0
L
Rb
[7:0] Register List
[10:8] Base Register
[11] Load/Store Bit
0 = Store to memory
1 = Load from memory
Figure 3-44. Format 15
OPERATION
These instructions allow multiple loading and storing of Lo registers. The THUMB assembler syntax is shown in
the following table.
Table 3-22. The Multiple Load/Store Instructions
L
THUMB Assembler
ARM Equivalent
Action
0
STMIA Rb!, { Rlist }
STMIA Rb!, { Rlist }
Store the registers specified by Rlist, starting at the base
address in Rb. Write back the new base address.
1
LDMIA Rb!, { Rlist }
LDMIA Rb!, { Rlist }
Load the registers specified by Rlist, starting at the base
address in Rb. Write back the new base address.
INSTRUCTION CYCLE TIMES
All instructions in this format have an equivalent ARM instruction as shown in Table 3-22. The instruction cycle
times for the THUMB instruction are identical to that of the equivalent ARM instruction.
Examples
STMIA
R0!, {R3-R7}
; Store the contents of registers R3-R7
; starting at the address specified in
; R0, incrementing the addresses for each word.
; Write back the updated value of R0.
3-90
S3C4510B
INSTRUCTION SET
FORMAT 16: CONDITIONAL BRANCH
11
15
14
13
12
8
7
0
SOffset 8
1
1
0
1
Cond
[7:0] 8-bit Signed Immediate
[11:8] Condition
Figure 3-45. Format 16
OPERATION
The instructions in this group all perform a conditional Branch depending on the state of the CPSR condition
codes. The branch offset must take account of the prefetch operation, which causes the PC to be 1 word (4
bytes) ahead of the current instruction.
The THUMB assembler syntax is shown in the following table.
Table 3-23. The Conditional Branch Instructions
Code
THUMB
ARM Equivalent
Action
Assembler
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
BEQ label
BNE label
BCS label
BCC label
BMI label
BPL label
BVS label
BVC label
BHI label
BLS label
BGE label
BEQ label
BNE label
BCS label
BCC label
BMI label
BPL label
BVS label
BVC label
BHI label
BLS label
BGE label
Branch if Z set (equal)
Branch if Z clear (not equal)
Branch if C set (unsigned higher or same)
Branch if C clear (unsigned lower)
Branch if N set (negative)
Branch if N clear (positive or zero)
Branch if V set (overflow)
Branch if V clear (no overflow)
Branch if C set and Z clear (unsigned higher)
Branch if C clear or Z set (unsigned lower or same)
Branch if N set and V set, or N clear and V clear
(greater or equal)
3-91
INSTRUCTION SET
S3C4510B
Table 3-23. The Conditional Branch Instructions (Continued)
Code
THUMB
ARM Equivalent
Action
Assembler
BLT label
BGT label
1011
1100
BLT label
BGT label
Branch if N set and V clear, or N clear and V set (less than)
Branch if Z clear, and either N set and V set or N clear and V
clear (greater than)
1101
BLE label
BLE label
Branch if Z set, or N set and V clear, or N clear and V set
(less than or equal)
NOTES:
1. While label specifies a full 9-bit two’s complement address, this must always be half-word-aligned (ie with bit 0 set to 0)
since the assembler actually places label >> 1 in field SOffset8.
2. Cond = 1110 is undefined, and should not be used.
Cond = 1111 creates the SWI instruction: see .
INSTRUCTION CYCLE TIMES
All instructions in this format have an equivalent ARM instruction as shown in Table 3-23. The instruction cycle
times for the THUMB instruction are identical to that of the equivalent ARM instruction.
Examples
CMP R0, #45
; Branch to over-if R0 > 45.
BGT over
; Note that the THUMB opcode will contain
; the number of half-words to offset.
...
...
...
...
over
; Must be half-word aligned.
3-92
S3C4510B
INSTRUCTION SET
FORMAT 17: SOFTWARE INTERRUPT
11
10
9
15
14
13
12
8
7
0
Value 8
1
1
0
1
1
1
1
1
[7:0] Comment Field
Figure 3-46. Format 17
OPERATION
The SWI instruction performs a software interrupt. On taking the SWI, the processor switches into ARM state and
enters Supervisor (SVC) mode.
The THUMB assembler syntax for this instruction is shown below.
Table 3-24. The SWI Instruction
THUMB Assembler
ARM Equivalent
Action
SWI Value 8
SWI Value 8
Perform Software Interrupt:
Move the address of the next instruction into LR, move CPSR
to SPSR, load the SWI vector address (0x8) into the PC.
Switch to ARM state and enter SVC mode.
NOTE: Value 8 is used solely by the SWI handler; it is ignored by the processor.
INSTRUCTION CYCLE TIMES
All instructions in this format have an equivalent ARM instruction as shown in Table 3-24. The instruction cycle
times for the THUMB instruction are identical to that of the equivalent ARM instruction.
Examples
SWI 18
; Take the software interrupt exception.
; Enter Supervisor mode with 18 as the
; requested SWI number.
3-93
INSTRUCTION SET
S3C4510B
FORMAT 18: UNCONDITIONAL BRANCH
11
10
15
14
13
12
0
Offset11
1
1
1
0
0
[10:0] Immediate Value
Figure 3-47. Format 18
OPERATION
This instruction performs a PC-relative Branch. The THUMB assembler syntax is shown below. The branch offset
must take account of the prefetch operation, which causes the PC to be 1 word (4 bytes) ahead of the current
instruction.
Table 3-25. Summary of Branch Instruction
THUMB Assembler
ARM Equivalent
Action
B label
BAL label (half-word offset) Branch PC relative +/- Offset11 << 1, where label is PC
+/- 2048 bytes.
NOTE: The address specified by label is a full 12-bit two¢s complement address,
but must always be half-word aligned (ie bit 0 set to 0), since the assembler places label >> 1 in the Offset11 field.
Examples
here
B here
; Branch onto itself. Assembles to 0xE7FE.
; (Note effect of PC offset).
B jimmy
...
; Branch to 'jimmy'.
; Note that the THUMB opcode will contain the number of
; half-words to offset.
Jimmy
...
; Must be half-word aligned.
3-94
S3C4510B
INSTRUCTION SET
FORMAT 19: LONG BRANCH WITH LINK
11
10
15
14
13
12
0
Offset
1
1
1
1
H
[10:0] Long Branch and Link Offset High/Low
[11] Low/High Offset Bit
0 = Offset high
1 = Offset low
Figure 3-48. Format 19
OPERATION
This format specifies a long branch with link.
The assembler splits the 23-bit two’s complement half-word offset specified by the label into two 11-bit halves,
ignoring bit 0 (which must be 0), and creates two THUMB instructions.
Instruction 1 (H = 0)
In the first instruction the Offset field contains the upper 11 bits of the target address. This is shifted left by 12 bits
and added to the current PC address. The resulting address is placed in LR.
Instruction 2 (H =1)
In the second instruction the Offset field contains an 11-bit representation lower half of the target address. This is
shifted left by 1 bit and added to LR. LR, which now contains the full 23-bit address, is placed in PC, the address
of the instruction following the BL is placed in LR and bit 0 of LR is set.
The branch offset must take account of the prefetch operation, which causes the PC to be 1 word (4 bytes) ahead
of the current instruction.
3-95
INSTRUCTION SET
S3C4510B
INSTRUCTION CYCLE TIMES
This instruction format does not have an equivalent ARM instruction.
Table 3-26. The BL Instruction
H
0
1
THUMB Assembler
ARM Equivalent
Action
LR := PC + OffsetHigh << 12
BL label
none
temp := next instruction address
PC := LR + OffsetLow << 1
LR := temp | 1
Examples
BL faraway
...
; Unconditionally Branch to 'faraway'
; and place following instruction
next
; address, ie “next”, in R14,the Link
; register and set bit 0 of LR high.
; Note that the THUMB opcodes will
; contain the number of half-words to offset.
; Must be Half-word aligned.
faraway
...
3-96
S3C4510B
INSTRUCTION SET
INSTRUCTION SET EXAMPLES
The following examples show ways in which the THUMB instructions may be used to generate small and efficient
code. Each example also shows the ARM equivalent so these may be compared.
MULTIPLICATION BY A CONSTANT USING SHIFTS AND ADDS
The following shows code to multiply by various constants using 1, 2 or 3 Thumb instructions alongside the ARM
equivalents. For other constants it is generally better to use the built-in MUL instruction rather than using a
sequence of 4 or more instructions.
Thumb
ARM
1. Multiplication by 2^n (1,2,4,8,...)
LSL
Ra, Rb, LSL #n
; MOV Ra, Rb, LSL #n
; ADD Ra, Rb, Rb, LSL #n
2. Multiplication by 2^n+1 (3,5,9,17,...)
LSL
ADD
Rt, Rb, #n
Ra, Rt, Rb
3. Multiplication by 2^n-1 (3,7,15,...)
LSL
SUB
Rt, Rb, #n
Ra, Rt, Rb
; RSB Ra, Rb, Rb, LSL #n
4. Multiplication by -2^n (-2, -4, -8, ...)
LSL
MVN
Ra, Rb, #n
Ra, Ra
; MOV Ra, Rb, LSL #n
; RSB Ra, Ra, #0
5. Multiplication by -2^n-1 (-3, -7, -15, ...)
LSL
SUB
Rt, Rb, #n
Ra, Rb, Rt
; SUB Ra, Rb, Rb, LSL #n
Multiplication by any C = {2^n+1, 2^n-1, -2^n or -2^n-1} * 2^n
Effectively this is any of the multiplications in 2 to 5 followed by a final shift. This allows the following additional
constants to be multiplied. 6, 10, 12, 14, 18, 20, 24, 28, 30, 34, 36, 40, 48, 56, 60, 62 .....
(2..5)
LSL
; (2..5)
; MOV Ra, Ra, LSL #n
Ra, Ra, #n
3-97
INSTRUCTION SET
S3C4510B
GENERAL PURPOSE SIGNED DIVIDE
This example shows a general purpose signed divide and remainder routine in both Thumb and ARM code.
Thumb code
;signed_divide
; Signed divide of R1 by R0: returns quotient in R0,
; remainder in R1
;Get abs value of R0 into R3
ASR
EOR
SUB
R2, R0, #31
R0, R2
R3, R0, R2
; Get 0 or -1 in R2 depending on sign of R0
; EOR with -1 (0xFFFFFFFF) if negative
; and ADD 1 (SUB -1) to get abs value
;SUB always sets flag so go & report division by 0 if necessary
BEQ divide_by_zero
;Get abs value of R1 by xoring with 0xFFFFFFFF and adding 1 if negative
ASR
EOR
SUB
R0, R1, #31
R1, R0
R1, R0
; Get 0 or -1 in R3 depending on sign of R1
; EOR with -1 (0xFFFFFFFF) if negative
; and ADD 1 (SUB -1) to get abs value
;Save signs (0 or -1 in R0 & R2) for later use in determining ; sign of quotient & remainder.
PUSH {R0, R2}
;Justification, shift 1 bit at a time until divisor (R0 value) ; is just <= than dividend (R1 value). To do this shift
dividend ; right by 1 and stop as soon as shifted value becomes >.
LSR
MOV
B
R0, R1, #1
R2, R3
%FT0
just_l
0
LSL
CMP
BLS
MOV
B
R2, #1
R2, R0
just_l
R0, #0
%FT0
; Set accumulator to 0
; Branch into division loop
div_l
0
LSR
CMP
BCC
SUB
ADC
CMP
BNE
R2, #1
R1, R2
%FT0
R1, R2
R0, R0
R2, R3
div_l
; Test subtract
; If successful do a real subtract
0
; Shift result and add 1 if subtract succeeded
; Terminate when R2 == R3 (ie we have just
; tested subtracting the 'ones' value).
;Now fix up the signs of the quotient (R0) and remainder (R1)
POP
EOR
EOR
SUB
EOR
SUB
MOV
{R2, R3}
R3, R2
R0, R3
R0, R3
R1, R2
R1, R2
pc, lr
; Get dividend/divisor signs back
; Result sign
; Negate if result sign = -1
; Negate remainder if dividend sign = -1
3-98
S3C4510B
INSTRUCTION SET
ARM Code
signed_divide
; Effectively zero a4 as top bit will be shifted out later
ANDS
RSBMI
EORS
a4, a1, #&80000000
a1, a1, #0
ip, a4, a2, ASR #32
;ip bit 31 = sign of result
;ip bit 30 = sign of a2
RSBCS
a2, a2, #0
;Central part is identical code to udiv (without MOV a4, #0 which comes for free as part of signed entry sequence)
MOVS
BEQ
a3, a1
divide_by_zero
just_l
div_l
; Justification stage shifts 1 bit at a time
; NB: LSL #1 is always OK if LS succeeds
CMP
MOVLS
BLO
a3, a2, LSR #1
a3, a3, LSL #1
s_loop
CMP
a2, a3
ADC
SUBCS
TEQ
a4, a4, a4
a2, a2, a3
a3, a1
MOVNE
BNE
a3, a3, LSR #1
s_loop2
MOV
a1, a4
MOVS
RSBCS
RSBMI
MOV
ip, ip, ASL #1
a1, a1, #0
a2, a2, #0
pc, lr
3-99
INSTRUCTION SET
S3C4510B
DIVISION BY A CONSTANT
Division by a constant can often be performed by a short fixed sequence of shifts, adds and subtracts.
Here is an example of a divide by 10 routine based on the algorithm in the ARM Cookbook in both Thumb and
ARM code.
Thumb Code
udiv10
; Take argument in a1 returns quotient in a1,
; remainder in a2
MOV
LSR
SUB
LSR
ADD
LSR
ADD
LSR
ADD
LSR
ASL
ADD
ASL
SUB
CMP
BLT
a2, a1
a3, a1, #2
a1, a3
a3, a1, #4
a1, a3
a3, a1, #8
a1, a3
a3, a1, #16
a1, a3
a1, #3
a3, a1, #2
a3, a1
a3, #1
a2, a3
a2, #10
%FT0
ADD
SUB
a1, #1
a2, #10
0
MOV
pc, lr
ARM Code
udiv10
; Take argument in a1 returns quotient in a1,
; remainder in a2
SUB
a2, a1, #10
SUB
ADD
ADD
ADD
MOV
ADD
SUBS
ADDPL
ADDMI
MOV
a1, a1, a1, lsr #2
a1, a1, a1, lsr #4
a1, a1, a1, lsr #8
a1, a1, a1, lsr #16
a1, a1, lsr #3
a3, a1, a1, asl #2
a2, a2, a3, asl #1
a1, a1, #1
a2, a2, #10
pc, lr
3-100
S3C4510B
SYSTEM MANAGER
4
SYSTEM MANAGER
OVERVIEW
The S3C4510B microcontroller's System Manager has the following functions.
·
·
To arbitrate system bus access requests from several master blocks, based on fixed priorities.
To provide the required memory control signals for external memory accesses. For example, if a master
block such as the DMA controller or the CPU generates an address which corresponds to a DRAM bank, the
System Manager's DRAM controller generates the required normal/EDO or SDRAM access signals. The
interface signals for normal/EDO or SDRAM can be switched by SYSCFG[31].
·
·
·
To provide the required signals for bus traffic between the S3C4510B and ROM/SRAM and the external I/O
banks.
To compensate for differences in bus width for data flowing between the external memory bus and the
internal data bus.
S3C4510B supports both little and big endian for external memory or I/O devices.
NOTE
By generating an external bus request, an external device can access the S3C4510B's external memory
interface pins. In addition, the S3C4510B can access slow external devices using a Wait signal. The Wait
signal, which is generated by the external device, extends the duration of the CPU's memory access
cycle beyond its programmable value.
4-1
SYSTEM MANAGER
S3C4510B
SYSTEM MANAGER REGISTERS
To control external memory operations, the System Manager uses a dedicated set of special registers (see Table
4-1). By programming the values in the System Manager special registers, you can specify such things as
·
·
·
·
·
Memory type
External bus width access cycle
Control signal timing (RAS and CAS, for example)
Memory bank locations
The sizes of memory banks to be used for arbitrary address spacing
The System Manager uses special register settings to control the generation and processing of the control
signals, addresses, and data that are required by external devices in a standard system configuration. Special
registers are also used to control access to ROM/SRAM/Flash banks, up to four DRAM banks and four external
I/O banks, and a special register mapping area.
The address resolution for each memory bank base pointer is 64K-bytes (16 bits). The base address pointer is 10
bits. This gives a total addressable memory bank space of 16 M words.
NOTE
When writing a value to a memory bank control register from ROMCON0 to REFEXTCON (locations
0x3014 to 0x303C), as shown in Table 4-1, you must always set the register using a single STM (Store
Multiple) instruction. Additionally, the address spaces for successive memory banks must not overlap in
the system memory map.
4-2
S3C4510B
SYSTEM MANAGER
0x3FFFFFF
Reserved
Special Register Bank
Internal SRAM
16K words (fixed)
0, 4 or 8K bytes (fixed)
External I/O Bank 3
External I/O Bank 2
Continuous 16K word space
for 4 external I/O banks
External I/O Bank 1
4K words
(Fixed for all I/O banks)
External I/O Bank 0
DRAM/SDRAM Bank 3
DRAM/SDRAM Bank 2
DRAM/SDRAM Bank 1
DRAM/SDRAM Bank 0
ROM/SRAM/Flash Bank 5
ROM/SRAM/Flash Bank 4
ROM/SRAM/Flash Bank 3
ROM/SRAM/Flash Bank 2
ROM/SRAM/Flash Bank 1
ROM/SRAM/Flash Bank 0
16M words
(16 M X 32 bits)
SA [25:0]
16K words-4M words (32 bits)
ADDR [21:0]
0x0000000
NOTE:
You can define banks anywhere within the 64-Mbyte address space.
Figure 4-1. S3C4510B System Memory Map
4-3
SYSTEM MANAGER
S3C4510B
SYSTEM MEMORY MAP
Following are several important features to note about the S3C4510B system memory map:
·
·
·
The size and location of each memory bank is determined by the register settings for "current bank base
pointer" and "current bank end pointer". You can use this base/next bank pointer concept to set up a
consecutive memory map. To do this, you set the base pointer of the "next bank" to the same address as the
next pointer of the "current bank". Please note that when setting the bank control registers, the address
boundaries of consecutive banks must not overlap. This can be applied even if one or more banks are
disabled.
Four external I/O banks are defined in a continuous address space. A programmer can only set the base
pointer for external I/O bank 0. The start address of external I/O bank 1 is then calculated as the external I/O
bank 0 start address +16 K. Similarly, the start address for external I/O bank 2 is the external I/O bank 0 start
address + 32 K, and the start address for external I/O bank 3 is the external I/O bank 0 start address + 48 K.
Therefore, the total consecutive addressable space of the four external banks is defined as the start address
of external I/O bank 0 + 64 K bytes.
Within the addressable space, the start address of each I/O bank is not fixed. You can use bank control
registers to assign a specific bank start address by setting the bank's base pointer. The address resolution is
64 K bytes. The bank's start address is defined as "base pointer << 16" and the bank's end address (except
for external I/O banks) is "next pointer << 16 - 1".
After a power-on or system reset, all bank address pointer registers are initialized to their default values. In this
case, all bank pointers except for the next pointer of ROM bank 0 are set to zero. This means that, except for
ROM bank 0, all banks are undefined following a system start-up.
The reset values for the next pointer and base pointer of ROM bank 0 are 0x200 and 0x000, respectively. This
means that a system reset automatically defines ROM bank 0 as a 32-Mbyte space with a start address of zero.
This initial definition of ROM bank 0 lets the system power-on or reset operation pass control to the user-supplied
boot code that is stored in external ROM. (This code is located at address 0 in the system memory map.) When
the boot code (i.e. ROM program) executes, it performs various system initialization tasks and reconfigures the
system memory map according to the application's actual external memory and device configuration.
The initial system memory map following system start-up is shown in Figure 4-2.
4-4
S3C4510B
SYSTEM MANAGER
0X3FFFFFF
0X3FF8000
Special Function Registers
Undefined Area
64 M Bytes
SA[25:0]
0X2000000
ROM/SRAM/FLASH Bank 0 Area
(Non-Accessible)
32 M
ROM/SRAM/FLASH Bank 0 Area
(Accessible)
4 M Address[21:0]
0X0000000
Figure 4-2. Initial System Memory Map (After Reset)
Table 4-1. System Manager Registers
Registers
Offset
0x0000
0x3000
0x3008
0x300C
0x3010
0x3014
0x3018
0x301C
0x3020
0x3024
0x3028
0x302C
0x3030
0x3034
0x3038
0x303C
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Description
System configuration register
Clock control register
Reset Value
0x37FFFF91
0x00000000
0x00000000
0x00000000
0x00000000
SYSCFG
CLKCON
EXTACON0
EXTACON1
EXTDBWTH
ROMCON0
ROMCON1
ROMCON2
ROMCON3
ROMCON4
ROMCON5
DRAMCON0
DRAMCON1
DRAMCON2
DRAMCON3
External I/O timing register 1
External I/O timing register 2
Data bus width of each bank
ROM/SRAM/Flash bank 0 control register
ROM/SRAM/Flash bank 1 control register
ROM/SRAM/Flash bank 2 control register
ROM/SRAM/Flash bank 3 control register
ROM/SRAM/Flash bank 4 control register
ROM/SRAM/Flash bank 5 control register
DRAM bank 0 control register
0x20000060
0x00000060
0x00000060
0x00000060
0x00000060
0x00000060
0x00000000
0x00000000
0x00000000
0x00000000
0x000083FD
DRAM bank 1 control register
DRAM bank 2 control register
DRAM bank 3 control register
REFEXTCON
Refresh and external I/O control register
4-5
SYSTEM MANAGER
S3C4510B
EXTERNAL ADDRESS TRANSLATION METHOD DEPENDS ON THE WIDTH OF EXTERNAL MEMORY
The S3C4510B address bus is, in some respects, different than the bus used in other standard CPUs. Based on
the required data bus width of each memory bank, the internal system address bus is shifted out to an external
address bus, ADDR[21:0]. This means that memory control signals such as nRAS[3:0], nCAS[3:0], nECS[3:0],
nRCS[5:0], and nWBE[3:0] are generated by the system manager according to a pre-configured external memory
scheme (see Table 4-2). This is applied to SDRAM signals as same method.
Table 4-2. Address Bus Generation Guidelines
Data Bus Width
8-bit
External Address Pins, ADDR[21:0]
A21–A0 (internal)
Accessible Memory Size
4M bytes
16-bit
A22–A1 (internal)
4M half-words
4M words
32-bit
A23–A2 (internal)
Data Bus Width Configuration
(8-bit/16-bit/32-bit)
SA [21:0]
22-bit
8-bit
External Address Pins
ADDR [21:0]
SA [22:1]
22-bit
16-bit
32-bit
22-bit
SA [23:2]
22-bit
System Address Bus: SA [25:0]
Figure 4-3. External Address Bus Diagram
4-6
S3C4510B
SYSTEM MANAGER
CONNECTION OF EXTERNAL MEMORY WITH VARIOUS DATA WIDTH
As another example, let us see how the S3C4510B maps CPU address spaces to physical addresses in external
memory:
When the CPU issues an arbitrary address to access an external memory device, the S3C4510B compares the
upper 10 bits of the issued address with the address pointers of all memory banks. It does this by consecutively
subtracting each address pointer value from the CPU address. There are two reasons why this subtraction
method is used:
·
To check the polarities of the subtraction result so as to identify which bank corresponds to the address
issued by the CPU.
·
To derive the offset address for the corresponding bank.
When the bank is identified and the offset has been derived, the corresponding bank selection signal (nRCS[5:0],
or nECS[3:0]) is generated, and the derived offset is driven to address external memory through the S3C4510B
physical address bus.
The S3C4510B can be configured as big-endian or little-endian mode by external little/big selection pin(LITTLE,
49).
In Big Endian mode, the most significant byte of the external memory data is stored at the lowest numbered byte
and the least significant byte at the highest numbered byte.
Eg.) In case of the external word memory system, Byte 0 of the memory is connected to data lines 31 through
24, D[31:24].
In Little Endian mode, vice versa.(See Figure 4-4 External Memory Interface)
4-7
SYSTEM MANAGER
ENDIAN MODES
S3C4510B
S3C4510B supports both little-endian and big-endian for external memory or I/O devices by setting the pin
LITTLE (pin 49).The system diagram for S3C4510B is shown in Figure 4-4.
S3C4510B
External Memory
CPU
(ARM7TMDI)
Memory
31
0
Bit Number
Controller
CPU Addr.
SA (Addr.)
SD (Data)
ADDR
...X0
...X4
CPU Data Bus
XDATA
Word Address
...X8
...XC
31
0
31
0
CPU Register
Special Register
Figure 4-4. Data Bus Connection with External Memory
Below tables (4-4 through 4-14) are show the program/data path between the CPU register and the external
memory using little-/big-endian and word/half-word/byte access.
4-8
S3C4510B
SYSTEM MANAGER
Table 4-3 and Table 4-4
Using big-endian and word access, Program/Data path between register and external memory
WA=Address whose LSB is 0, 4, 8, C
X=Don't care
CAS3-0/nWBE3-0=0 means active and 1 means inactive
Table 4-3. Word Access Store Operation with Big-Endian
STORE (CPU Reg ® External Memory)
Ext. Memory Type
Word
Half Word
Byte
Bit Num.
31
0
31
0
31 0
CPU Register Data
abcd
WA
abcd
WA
abcd
WA
CPU Address
Bit Num.
31
0
31
0
31
0
31
0
31
0
31
0
31 0
CPU Data Bus
abcd
abcd
abcd
abcd
abcd
abcd
abcd
Bit Num.
31
0
31
0
31
0
31
0
31
0
31
0
31 0
Internal SD Bus
abcd
WA
abcd
WA
abcd
abcd
WA
abcd
WA + 1
XXX0
abcd
abcd
WA + 3
XXX0
External Address
CAS3-0/nWBE3-0
WA + 2
XX00
WA + 2
XXX0
0000
XX00
XXX0
Bit Num.
XDATA
31
0
15
0
15
0
7
0
7
0
7
0
7
0
abcd
ab
cd
a
a
b
b
c
c
d
d
Bit Num.
Ext. Memory Data
31
0
15
0
15
0
7
0
7
0
7
0
7
0
abcd
ab
cd
Timing Sequence
1st write 2nd write 1st write 2nd write 3rd write 4th write
Table 4-4 Word Access Load Operation with Big-Endian
LOAD (CPU Reg ¬ External Memory)
Ext. Memory Type
Word
Half Word
Byte
Bit Num.
31
0
31
0
31 0
CPU Register Data
abcd
WA
abcd
WA
abcd
WA
CPU Address
Bit Num.
31
0
31
0
31
0
31
0
31
0
31
0
31 0
CPU Data Bus
abcd
abXX
abcd
aXXX
abXX
abcX
abcd
Bit Num.
31
0
31
0
31
0
31
0
31
0
31
0
31 0
Internal SD Bus
abcd
WA
abXX
WA
abcd
aXXX
WA
abXX
WA + 1
XXX0
abcX
abcd
WA + 3
XXX0
External Address
CAS3-0/nWBE3-0
WA + 2
XX00
WA + 2
XXX0
0000
XX00
XXX0
Bit Num.
XDATA
31
0
15
0
15
0
7
0
7
0
7
0
7
0
abcd
ab
cd
a
a
b
b
c
c
d
d
Bit Num.
Ext. Memory Data
31
0
15
0
15
0
7
0
7
0
7
0
7
0
abcd
ab
cd
Timing Sequence
1st read 2nd read 1st read 2nd read 3rd read
4th read
4-9
SYSTEM MANAGER
S3C4510B
Table 4-5 and 4-6
Using big-endian and half-word access, Program/Data path between register and external memory.
HA=Address whose LSB is 0, 2, 4, 6, 8, A, C, E
HAU=Address whose LBS is 2, 6, A, E
HAL=Address whose LSB is 0, 4, 8, C
X=Don't care
CAS3-0/nWBE3-0=0 means active and 1 means inactive
Table 4-5. Half-Word Access Store Operation with Big-Endian
STORE (CPU Reg ® External Memory)
Ext. Memory Type
Bit Num.
Word
Half word
Byte
31
0
31
0
31 0
CPU Register Data
abcd
abcd
HA
abcd
HA
CPU Address
HAL
HAU
Bit Num.
31
0
31
0
31
0
31
0
31 0
CPU Data Bus
cdcd
cdcd
cdcd
cdcd
cdcd
Bit Num.
31
0
31
0
31
0
31
0
31 0
Internal SD Bus
cdcd
HAL
0011
cdcd
HAL
1100
cdcd
HA
cdcd
HA
cdcd
HA + 1
XXX0
External Address
CAS3-0/nWBE3-0
XX00
XXX0
Bit Num.
XDATA
31
0
31
0
15
0
7
0
7
0
cdXX
XXcd
cd
c
c
d
d
Bit Num.
Ext. Memory Data
31 16
15
0
15
0
7
0
7
0
cd
cd
cd
Timing Sequence
1st write 2nd write
Table 4-6. Half-Word Access Load Operation with Big-Endian
LOAD (CPU Reg ¬ External Memory)
Ext. Memory Type
Bit Num.
Word
Half word
Byte
15
0
15
0
15 0
CPU Register Data
ab
ab
HA
ab
HA
CPU Address
HAL
HAU
Bit Num.
31
0
31
0
31
0
31
0
31 0
CPU Data Bus
abab
cdcd
abab
aXaX
abab
Bit Num.
31
0
31
0
31
0
31
0
31 0
Internal SD Bus
abab
HAL
cdcd
HAL
abab
HA
aXaX
HA
abab
HA + 1
XXXX
External Address
CAS3-0/nWBE3-0
XXXX
XXXX
XXXX
XXXX
Bit Num.
XDATA
31
0
31
0
15
0
7
0
7
0
abcd
abcd
ab
a
a
b
b
Bit Num.
Ext. Memory Data
31
0
15
0
7
0
7
0
abcd
ab
Timing Sequence
1st read
2nd read
4-10
S3C4510B
SYSTEM MANAGER
Table 4-7 and 4-8
Using big-endian and byte access, Program/Data path between register and external memory
BA=Address whose LSB is 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F
BAL=Address whose LSB is 0,2,4,6,8,A,C,E
BAU=Address whose LBS is 1,3,5,7,9,B,D,F
BA0=Address whose LSB is 0,4,8,C
BA1=Address whose LBS is 1,5,9,D
BA2=Address whose LSB is 2,6,A,E
BA3=Address whose LBS is 3,7,B,F
X=Don't care
CAS3-0/nWBE3-0=0 means active and 1 means inactive
Table 4-7. Byte Access Store Operation with Big-Endian
STORE (CPU Reg ® External Memory)
Ext. Memory Type
Bit Num.
Word
Half Word
Byte
31
0
31
0
31 0
CPU Register Data
abcd
abcd
abcd
BA
CPU Address
BA0
BA1
BA2
BA3
BAL
BAU
Bit Num.
31
0
31
0
31
0
31
0
31
0
31
0
31 0
CPU Data Bus
dddd
dddd
dddd
dddd
dddd
dddd
dddd
Bit Num.
31
0
31
0
31
0
31
0
31
0
31
0
31 0
Internal SD Bus
dddd
BA0
dddd
BA0
dddd
BA0
dddd
BA0
dddd
BAL
dddd
BAL
dddd
BA
External Address
CAS3-0/nWBE3-0
0111
1011
1101
1110
XX10
XX01
XXX0
Bit Num.
XDATA
31
0
31
0
31
0
31
0
15
0
15
0
7
0
dXXX
XdXX
XXdX
XXXd
dX
Xd
d
d
Bit Num.
Ext. Memory Data
31 24
23 16
15
8
7
0
15
0
15
0
7
0
d
d
d
d
d
d
Timing Sequence
4-11
SYSTEM MANAGER
S3C4510B
Table 4-8. Byte Access Load Operation with Big-Endian
LOAD (CPU Reg ¬ External Memory)
Ext. Memory Type
Word
Half Word
Byte
Bit Num.
7
0
7
0
7 0
CPU Register Data
a
a
a
CPU Address
BA0
BA1
BA2
BA3
BAL
BAU
BA
Bit Num.
31
0
31
0
31
0
31
0
31
0
31
0
31 0
CPU Data Bus
aaaa
bbbb
cccc
dddd
aaaa
bbbb
aaaa
Bit Num.
31
0
31
0
31
0
31
0
31
0
31
0
31 0
Internal SD Bus
aaaa
BA0
bbbb
BA0
cccc
BA0
dddd
BA0
aaaa
BAL
bbbb
BAL
aaaa
BA
External Address
CAS3-0/nWBE3-0
XXXX
XXXX
XXXX
XXXX
XXXX
XXXX
XXXX
Bit Num.
XDATA
31
0
31
0
31
0
31
0
15
0
15
0
7
0
abcd
abcd
abcd
abcd
ab
ab
a
a
Bit Num.
Ext. Memory Data
31
0
15
0
7
0
abcd
ab
Timing Sequence
4-12
S3C4510B
SYSTEM MANAGER
Table 4-9 and 4-10
Using little-endian and word access, Program/Data path between register and external memory
WA=Address whose LSB is 0,4,8,C
X=Don't care
CAS3-0/nWBE3-0=0 means active and 1 means inactive
Table 4-9. Word Access Store Operation with Little-Endian
STORE (CPU Reg ® External Memory)
Ext. Memory Type
Bit Num.
Word
Half Word
Byte
31
0
31
0
31 0
abcd
abcd
abcd
CPU Register Data
CPU Address
Bit Num.
WA
WA
WA
31
0
31
0
31
0
31
0
31
0
31
0
31 0
abcd
abcd
abcd
abcd
abcd
abcd
abcd
CPU Data Bus
Bit Num.
31
0
31
0
31
0
31
0
31
0
31
0
31 0
abcd
abcd
abcd
abcd
abcd
abcd
abcd
Internal SD Bus
External Address
Bit Num.
WA
WA
WA + 2
WA
WA + 1
WA + 2
31
0
15 0
15 0
7
7
0
0
7
7
0
0
7
7
0
0
7
7
0
0
abcd
cd
ab
d
c
c
b
b
a
XDATA
Bit Num.
31
0
15 0
15 0
abcd
cd
ab
d
a
Ext. Memory Data
Timing Sequence
1st write 2nd write 1st write 2nd write 3rd write 4th write
Table 4-10. Word Access Load Operation with Little-Endian
LOAD (CPU Reg ¬ External Memory)
Ext. Memory Type
Word
Half Word
Byte
Bit Num.
31
0
31
0
31 0
CPU Register Data
abcd
WA
abcd
WA
abcd
WA
CPU Address
Bit Num.
31
0
31
0
31
0
31
0
31
0
31
0
31 0
CPU Data Bus
abcd
XXcd
abcd
XXXd
XXcd
Xbcd
abcd
Bit Num.
31
0
31
0
31
0
31
0
31
0
31
0
31 0
Internal SD Bus
abcd
WA
XXcd
WA
abcd
XXXd
WA
XXcd
Xbcd
WA + 2
abcd
External Address
WA + 2
WA + 1
WA + 3
Bit Num.
XDATA
31
0
15 0
15 0
7
0
7
0
7
0
7
0
abcd
cd
ab
d
d
c
c
b
b
a
a
Bit Num.
Ext. Memory Data
31
0
15 0
15 0
7
0
7
0
7
0
7
0
abcd
cd
ab
Timing Sequence
1st read 2nd read 1st read 2nd read 3rd read
4th read
4-13
SYSTEM MANAGER
S3C4510B
Table 4-11 and 4-12
Using little-endian and half-word access, Program/Data path between register and external memory
HA=Address whose LSB is 0, 2, 4, 6, 8, A, C, E
HAU=Address whose LBS is 2, 6, A, E
HAL=Address whose LSB is 0, 4, 8, C
X=Don't care
CAS3-0/nWBE3-0=0 means active and 1 means inactive
Table 4-11. Half-Word Access Store Operation with Little-Endian
STORE (CPU Reg ® External Memory)
Ext. Memory Type
Bit Num.
Word
Half word
Byte
31 d0
31
0
31 0
CPU Register Data
abcd
abcd
HA
abc
CPU Address
HAL
HAU
HA
Bit Num.
31
0
31
0
31
0
31
0
31 0
CPU Data Bus
cdcd
cdcd
cdcd
cdcd
cdcd
Bit Num.
31
0
31
0
31
0
31
0
31 0
Internal SD Bus
cdcd
HAL
1100
cdcd
HAL
0011
cdcd
HA
cdcd
HA
cdcd
HA+1
XXX0
External Address
CAS3-0/nWBE3-0
XX00
XXX0
Bit Num.
XDATA
31
0
31
0
15
0
7
0
7
0
cdcd
cdcd
cd
d
d
c
c
Bit Num.
Ext. Memory Data
15
0
31 16
15
0
7
0
7
0
cd
cd
cd
Timing Sequence
1st write 2nd write
Table 4-12. Half-Word Access Load Operation with Little-Endian
LOAD (CPU Reg ¬ External Memory)
Ext. Memory Type
Bit Num.
Word
Half word
Byte
15
0
15
0
15 0
CPU Register Data
cd
ab
HA
ba
HA
CPU Address
HAL
HAU
Bit Num.
31
0
31
0
31
0
31
0
31 0
CPU Data Bus
cdcd
abab
abab
XaXa
baba
Bit Num.
31
0
31
0
31
0
31
0
31 0
Internal SD Bus
cdcd
HAL
abab
HAL
abab
HA
XaXa
HA
baba
HA+1
XXXX
External Address
CAS3-0/nWBE3-0
XXXX
XXXX
XXXX
XXXX
Bit Num.
XDATA
31
0
31
0
15
0
7
0
7
0
abcd
abcd
ab
a
a
b
b
Bit Num.
Ext. Memory Data
31
0
15
0
7
0
7
0
abcd
ab
Timing Sequence
1st read
2nd read
4-14
S3C4510B
SYSTEM MANAGER
Table 4-13 and 4-14
Using little-endian and byte access, Program/Data path between register and external memory
BA=Address whose LSB is 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F
BAL=Address whose LSB is 0,2,4,6,8,A,C,E
BAU=Address whose LBS is 1,3,5,7,9,B,D,F
BA0=Address whose LSB is 0,4,8,C
BA1=Address whose LBS is 1,5,9,D
BA2=Address whose LSB is 2,6,A,E
BA3=Address whose LBS is 3,7,B,F
X=Don't care
CAS3-0/nWBE3-0=0 means active and 1 means inactive
Table 4-13. Byte Access Store Operation with Little-Endian
STORE (CPU Reg ® External Memory)
Ext. Memory Type
Bit Num.
Word
Half Word
Byte
31
0
31
0
31 0
CPU Register Data
abcd
abcd
abcd
BA
CPU Address
BA0
BA1
BA2
BA3
BAL
BAU
Bit Num.
31
0
31
0
31
0
31
0
31
0
31
0
31 0
CPU Data Bus
dddd
dddd
dddd
dddd
dddd
dddd
dddd
Bit Num.
31
0
31
0
31
0
31
0
31
0
31
0
31 0
Internal SD Bus
dddd
BA0
dddd
BA0
dddd
BA0
dddd
BA0
dddd
BAL
dddd
BAL
dddd
BA
External Address
CAS3-0/nWBE3-0
1110
1101
1011
0111
XX10
XX01
XXX0
Bit Num.
XDATA
31
0
31
0
31
0
31
0
15
0
15
0
7
0
XXXd
XXdX
XdXX
dXXX
Xd
dX
d
d
Bit Num.
Ext. Memory Data
7
0
15
8
23 16
31 24
7
0
15
8
7
0
d
d
d
d
d
d
Timing Sequence
4-15
SYSTEM MANAGER
S3C4510B
Table 4-14. Byte Access Load Operation with Little-Endian
LOAD (CPU Reg ¬ External Memory)
Ext. Memory Type
Word
Bit Num.
7
0
7
0
7 0
CPU Register Data
d
c
a
CPU Address
BA0
BA1
BA3
Bit Num.
31
0
31
0
31
0
31
0
31
0
31
0
31 0
CPU Data Bus
dddd
cccc
bbbb
aaaa
bbbb
aaaa
aaaa
Bit Num.
31
0
31
0
31
0
31
0
31
0
31
0
31 0
Internal SD Bus
dddd
BA0
cccc
BA0
bbbb
BA0
aaaa
BA0
bbbb
BAL
aaaa
BAL
aaaa
BA
External Address
CAS3-0/nWBE3-0
XXXX
XXXX
XXXX
XXXX
XXXX
XXXX
XXXX
Bit Num.
XDATA
31
0
31
0
31
0
31
0
15
0
15
0
7
0
abcd
abcd
abcd
abcd
ab
ab
a
a
Bit Num.
Ext. Memory Data
31
0
15 0
7
0
abcd
ab
Timing Sequence
4-16
S3C4510B
SYSTEM MANAGER
BUS ARBITRATION
In the S3C4510B microcontroller, the term "system bus" refers to the separate system address and data buses
inside the chip. The S3C4510B's internal function blocks, or external devices, can request mastership of the
system bus and then hold the system bus in order to perform data transfers. Because the design of S3C4510B
bus allows only one bus master at a time, a bus controller is required to arbitrate when two or more internal units
or external devices simultaneously request bus mastership.
When bus mastership is granted to an internal function block or an external device, other pending requests are
not acknowledged until the previous bus master has released the bus.
To facilitate bus arbitration, priorities are assigned to each internal S3C4510B function block. The bus controller
arbitrattion requests for the bus mastership according to these fixed priorities. In the event of contention,
mastership is granted to the function block with the highest assigned priority. These priorities are listed in
Table 4-15.
NOTE
An external bus master can also be granted bus mastership and hold the S3C4510B system bus. In
Table 4-3, you will note that all external devices are assigned the identical priority. Therefore, in systems
made up of several external devices which can become the bus master, external circuitry must be
implemented to assign additional bus arbitration priorities to all potential external bus masters.
Table 4-15. Bus Priorities for Arbitration
Function Block
Bus Priority (Group)
External bus master
A-1 (Highest priority in Group A)
DRAM memory refresh controller
General DMA 1 (GDMA 1)
General DMA 0 (GDMA 0)
High level data link controller B (HDLC B)
High level data link controller A (HDLC A)
MAC buffered DMA (BDMA)
Writer buffer
A-2
A-3
A-4
A-5
A-6
A-7 (Lowest priority in Group A)
B-1 (Highest priority in Group B)
B-2 (Lowest priority in Group B)
Bus router
NOTE: Internal function blocks are divided into two groups, Group A and Group B. Within each group, the bus arbitration
priorities are fixed according to the assigned level. The relative priority of Group A and Group B is determined more
or less in an alternating manner.
4-17
SYSTEM MANAGER
S3C4510B
EXTERNAL BUS MASTERSHIP
The S3C4510B can receive and acknowledge bus request signals (ExtMREQs) that are generated by an external
bus master. When the CPU asserts an external bus acknowledge signal (ExtMACK), mastership is granted to the
external bus master, assuming the external bus request is still active.
When the external bus acknowledge signal is active, the S3C4510B's memory interface signals go to high-
impedance state so that the external bus master can drive the required external memory interface signals.
The S3C4510B does not perform DRAM refreshes when it is not the bus master. When an external bus master is
in control of the external bus, and if it retains control for a long period of time, it must assume the responsibility of
performing the necessary DRAM refresh operations.
SCLK
MCLKO
tEMZ
Address, Data, nOE,
nWBE, nDWE, nRCS
, nCAS, nRAS
Data
Data
tEMRh
tEMRs
ExtMREQ
ExtMACK
tEMAr
tEMAf
Figure 4-5. External Bus Request Timing
NOTE: When External Bus Master requests the ExtMREQ during the Sync DRAM writing cycles, the ExtMACK can be
generated with the wrong writing control signals of Sync DRAM. Just floating the Sync DRAM control signals at the
time ExtMACK , it can cause the feasible active writing on the Sync DRAM. As the result, the wrong data can be
written into unexpected address on Sync DRAM. If this address is in the range of stack or code area, the crash will
be happen sooner or later. The other memory interfaces doesn’t have this problem, which is asynchronous with
MCLKO, that is why Sync DRAM write cycle only. You can avoid this by disabling the SDCS (Sync DRAM Chip
Select HIGH) as soon as receiving the ExtMACK and driving the Address and Data after one or two MCLKO cycles.
4-18
S3C4510B
SYSTEM MANAGER
CONTROL REGISTERS
SYSTEM CONFIGURATION REGISTER (SYSCFG)
The System Manager has one system configuration register, SYSCFG. The SYSCFG register determines the
start address of the System Manager's special registers and the start address of internal SRAM. (The total special
register space in the system memory map is fixed at 64 K bytes.)
You also use SYSCFG settings to control write buffer enable, cache enable, and stall enable operations.
All DRAM banks can be configured to SDRAM banks by set the Synchronous DRAM mode (SYSCFG[31]).
NOTE
If you write a "10" into the cache mode field, SYSCFG[5:4], the cache enable bit is cleared automatically
(see Figure 4-6).
Table 4-16. SYSCFG Register
Registers
SYSCFG
Offset Address
R/W
Description
Reset Value
0x0000
R/W
System configuration register
0x37FFFF91
4-19
SYSTEM MANAGER
S3C4510B
31 30
26 25
16 15
6
5
4
3
2
1
0
S
Special Register Bank
Base Pointer
Internal SRAM
Base Pointer
W C S
E E E
PD_ID
D
CM
0
M
[0] Stall enable (SE)
Must be set to zero.
[1] Cache enable (CE)
When set to '1', cache operations are enabled.
[2] Write buffer enable (WE)
When set to "1", write buffer operations are enabled.
[5:4] Cache mode (CM)
This 2-bit value determines how internal memory is to be
devided into cache and SRAM.
00 = 4-Kbyte SRAM, 4Kbyte cache
01 = 0-Kbyte SRAM, 8Kbyte cache
10 = 8-Kbyte SRAM, 0Kbyte cache
NOTE:
When you write 10 to this field, the cache enable
bit is cleared automatically.
[15:6] Internal SRAM base pointer
This 10-bit address becomes the upper address of SRAM.
A25 through A16, the remaining SRAM address, and A15
through A0, are filled with zeros.
[25:16] Special register bank base pointer
The resolution of this value is 64K. Therefore, to place
the start address at 1800000H (24M), use this formula:
Setting value = (1800000H/64K) << 16.
[30:26] Product Identifier (PD_ID)
00001 = S3C4510X (KS32C50100)
11001 = S3C4510B
[31] Sync. DRAM Mode
0 = Normal/EDO DRAM interface for 4 DRAM banks
1 = Sync. DRAM interface for 4 DRAM banks.
Figure 4-6. System Configuration Register (SYSCFG)
4-20
S3C4510B
SYSTEM MANAGER
Start Address Setting
The start address of the System Manager special register area is initialized to 3FFFF91H. (You can also set the
start address to an arbitrary value by writing the address, 3FF0000H.) When you have set the start address of the
special register area, the register addresses are automatically defined as the start address plus the register’s
offset.
Assume for example, that a reset initialize the start address to 3FF0000H. The offset address of the ROMCON
register is 3014H. Therefore, the physical address for ROMCON is 3FF0000H + 3014h = 3FF3014H. If you then
modified the start address of the special register area to 3000000H, the new address for the ROMCON register
would be 3003014H.
Cache Disable/Enable
To enable or disable the cache, you set the cache enable (CE) bit of the SYSCFG register to "1" or "0",
respectively Because cache memory does not have an auto-flush feature, you must be careful to verify the
coherency of data whenever you re-enable the cache. You must also carefully check any changes that the DMA
controller may make to data stored in memory.
(Usually, the memory area that is allocated to DMA access operations must be non-cachable.)
The internal 8-Kbyte SRAM can be used as a cache area. To configure this area, you use the cache mode bits,
SYSCFG[5:4]. If you do not need to use the entire 8-Kbyte area as cache, you can use the remaining area as
internal SRAM. This area is accessed using the address of the base pointer in the internal SRAM field.
Write Buffer Disable/Enable
The S3C4510B has four programmable write buffer registers that are used to improve the speed of memory write
operations. When you enable a write buffer, the CPU writes data into the write buffer, instead of an external
memory location. This saves the cycle that would normally be required to complete the external memory write
operation. The four write buffers also enhance the performance of the ARM7TDMI core’s store operations.
To maintain data coherency between the cache and external memory, the S3C4510B uses a write-through policy.
An internal 4-level write buffer compensates for performance degradation caused by write-throughs.
(For more information, read Chapter 5.)
4-21
SYSTEM MANAGER
S3C4510B
SYSTEM CLOCK AND MUX BUS CONTROL REGISTER
CLOCK CONTROL REGISTER (CLKCON)
There is a clock control register in the System Manager. This control register is used to divide the internal system
clock, so the slower clock than the system clock can be made by clock dividing value. In this register, ROM bank
5 address/data MUX. enable control function is included.
Table 4-17. CLKCON Register
Registers
CLKCON
Offset Address
R/W
Description
Clock control register
Reset Value
0x3000
R/W
0x00000000
Table 4-18. CLKCON Register Description
Bit Number
Bit Name
Description
[15:0]
Clock dividing value
S3C4510B System Clock source. If CLKSEL is Low, PLL output
clock is used as the S3C4510B internal system clock. If CLKSEL
is High, XCLK is used as the S3C4510B internal system clock.
The internal system clock is divided by this value. The clock
divided is used to drive the CPU and system peripherals. Only
one bit can be set in CLKCON[15:0], that is, the clock deviding
value is defined as 1, 2, 4, 8, 16,... If all bits are zero, a non-
divided clock is used.
[16]
[17]
ROM bank 5 wait enable Wait cycle will check the next cycle after a chip selection signal is
activated.
ROM bank 5
address/data MUX.
enable
Using multiplex bus at ROM bank 5, this bit must be set to 1.
[19:18]
MUX Bus address cycle When address phase of multiplexed bus is not enough long for
external device to receive, address phase can be extended by
setting this bit.(You can see tAC in timing diagram.)
00 = 1 MCLK
01 = 2 MCLK
10 = 3 MCLK
[31]
Test bit
This bit is for factory use only. During the normal operation, it
must always be 0.
4-22
S3C4510B
SYSTEM MANAGER
31
20 19 18 17 16 15
0
CLKCON
Clock Divided Value
[15:0] Clock diving value
If all bits are 0, non-divided clock is used. Only one bit
can be set in CLKCON[15:0]. That is, the clock diving
value is defined as 1,2,4,8,16,...
Internal system clock, fMCLK = fICLK/(CLKCON+1)
[16] ROM bank 5 wait enable
0 = Disable ROM bank 5 wait.
1 = Enable ROM bank 5 wait.
[17] ROM bank 5 address/data bus MUX enable
0 = Normal operation
1 = Enable bus multiplexing
[19:18] MUX bus Address (tAC)
00 = 1 MCLK
01 = 2 MCLK
10 = 3 MCLK
[31] Test bit
This bit should be always 0.
Figure 4-7. Clock Control Register (CLKCON)
4-23
SYSTEM MANAGER
SYSTEM CLOCK
S3C4510B
The external clock input, XCLK, can be used to the internal system clock by assign VDD to CLKSEL pin. Using
PLL for the internal system clock, VSS has to be assigned to CLKSEL pin. In this case, the internal system clock
is XCLK ´ MF. To get 50MHz of system clock, a 10 MHz external clock must be used.
CLKSEL
pdown (1)
MF (2)
PLL
TMOD
XCLK
0: MF = 5.0
1: MF = 6.6
0
Clock Divider for
Low Power Control
(CLKCON)
Internal System
Clock SCLK
(MCLK)
ICLK
MUX
1
MCLKO
CLKOEN
NOTES:
1. If CLKSEL is 1, the PLL block became to the state of power down.
2. MF means Multiplication Factor.
Figure 4-8. System Clock Circuit
For the purpose of power save, Clock Control Register (CLKCON) can be programed at low frequency. When the
internal system clock is divided by CLKCON, it's duty-cycle is changed.
If CLKCON is programed to zero, the internal system clock remains the same as the internal clock, ICLK. In other
cases, the duty cycle of internal system clock is no longer 50%.
Figure 4-9 shows the internal system clock, SCLK(MCLK) waveform according to the clock dividing value.
ICLK
SCLK(MCLK)
CLKCON = 0
SCLK(MCLK)
CLKCON = 1
SCLK(MCLK)
CLKCON = 2
Figure 4-9. Divided System Clocks Timing Diagram
4-24
S3C4510B
SYSTEM MANAGER
EXTERNAL I/O ACCESS CONTROL REGISTERS (EXTACON0/1)
The System Manager has four external I/O access control registers. These registers correspond to the up to four
external I/O banks that are supported by S3C4510B. Table 4-19 describes the two registers that are used to
control the timing of external I/O bank accesses.
You can control external I/O access cycles using either a specified value or an external wait signal, nEWAIT. To
obtain access cycles that are longer than those possible with a specified value, you can delay the active time of
nOE or nWBE by tCOS value setting. After nOE or nWBE active, nEWAIT should be active previously at the first
MCLK(SCLK) falling edge. In case of ROM bank 5, nRCS and nOE/nWBE signals are activated simultaneously,
that is, there is no control parameter as like tCOS. As a result, nEWAIT should be valid previously at the second
MCLK(SCLK) falling edge after nRCS active for the ROM bank 5.
EXTACON0 is used to set the access timings for external I/O banks 0 and 1. EXTACON1 is used to set the
external access timings for I/O banks 2 and 3.
NOTE
The base pointer for external I/O bank 0 is set in the REFEXTCON register(REFEXTCON register is in
DRAM control registers part).
Table 4-19. External I/O Access Control Register Description
Registers
EXTACON0
EXTACON1
Offset Address
0x3008
R/W
R/W
R/W
Description
Reset Value
0x00000000
0x00000000
External I/O access timing register 0
External I/O access timing register 1
0x300C
4-25
SYSTEM MANAGER
S3C4510B
31 30 29 28 27
25 24
22 21
19 18
16 15 14 13 12 11
9
8
6
5
3
2
0
EXTACON0
EXTACON1
0
0
0
0
0
0
0
0
tACC1
tACC3
tCOH1
tCOH3
tACS1
tACS3
tCOS1
tCOS3
0
0
0
0
0
0
0
0
tACC0
tACC2
tCOH0
tCOH2
tACS0
tACS2
tCOS0
tCOS2
[2:0] Chip selection set-up time on nOE (tCOS0, tCOS2)
[18:16] tCOS1, tCOS3
000 = 0 cycle
001 = 1 cycle
010 = 2 cycles
011 = 3 cycles
100 = 4 cycles
101 = 5 cycles
110 = 6 cycles
111 = 7 cycles
[5:3] Address set-up time before nECS (tACS0, tACS2)
[21:19] tACS1, tACS3
000 = 0 cycle
001 = 1 cycle
010 = 2 cycles
011 = 3 cycles
100 = 4 cycles
101 = 5 cycle
110 = 6 cycle
111 = 7 cycles
[8:6] Chip selection hold time on nOE (tCOH0, tCOH2)
[24:22] tCOH1, tCOH3
000 = 0 cycle
001 = 1 cycle
010 = 2 cycles
011 = 3 cycles
100 = 4 cycles
101 = 5 cycles
110 = 6 cycles
111 = 7 cycles
[11:9] Access cycles (nOE low time) (tACC0, tACC2)
[27:25] tACC1, tACC3
000 = 0 cycle
001 = 1 cycle
010 = 2 cycles
011 = 3 cycles
100 = 4 cycles
101 = 5 cycles
110 = 6 cycles
111 = 7 cycles
Figure 4-10. External I/O Access Control Registers (EXTACON0, EXTACON1)
4-26
S3C4510B
SYSTEM MANAGER
SCLK
MCLKO
nECS
tNECS
tNECS
tNROE
tACC
tNROE
nOE
Address
Data
tADDRh
Addr
Data
nEWAIT
Data
Fetch
tACS = 0 (0 cycle)
tCOS = 0 (0 cycle)
tACC = 4 (5 cycles)
tCOH = 0 (0 cycle)
Figure 4-11. External I/O Read Timing 1
When nEWAIT is asserted for external I/O banks, the tCOS and tCOH should not be zero. When ROM banks,
except ROM bank 5, are selected, the nEWAIT can not be asserted.
Even if you does not use nEWAIT, nEWAIT pin should be connected pull-up for safe operation.
4-27
SYSTEM MANAGER
S3C4510B
SCLK
MCLKO
tNECS
tNECS
tCOH
tACC
tACS
tNROE
nECS
tNROE
nOE
Address
Data
tADDRh
Addr
Data
nEWAIT
Data
Fetch
tACS = 1 (1 cycle)
tCOS = 0 (0 cycle)
tACC = 3 (4 cycles)
tCOH = 1 (1 cycle)
Figure 4-12. External I/O Read Timing 2
4-28
S3C4510B
SYSTEM MANAGER
SCLK
MCLKO
nECS
tNECS
tCOH
tNECS
tACC
tACS
tNROE
tNROE
nOE
Address
Data
tCOS
tADDRd
Addr
Data
tWs
tWh
nEWAIT
Data Read Point
(tCOH = 1)
tACS = 1 (1 cycle)
tCOS = 1 (1 cycle)
tACC = 1 (2 cycles)
tCOH = 1 (1 cycle)
Figure 4-13. External I/O Read Timing with nEWAIT
The nEWAIT should be valid at the first SCLK falling edge after nOE active. In this case, tCOS and tCOH need
to have a minimum of one cycle, and by the setting of tCOS value slower device can be supported. Naimly,
nEWAIT valid time depends on tCOS value. Deassertion timing depends on the applied Ext. I/O devices.
When the nEWAIT de-assert, it must be synchronized with MCLKO rising edge.(Because we can not detect
SCLK falling edge.) If not, memory state machine can go into the wrong state.
4-29
SYSTEM MANAGER
S3C4510B
SCLK
MCLKO
tNECS
tNECS
tACC
nECS
tNWBE
tNWBE
nWBE
Address
Data
tADDRd
tADDRh
tWDh
Addr
Data
tWDd
nEWAIT
tACS = 0 (0 cycle)
tCOS = 0 (0 cycle)
tACC = 4 (5 cycles)
tCOH = 0 (0 cycle)
Figure 4-14. External I/O Write Timing 1
4-30
S3C4510B
SYSTEM MANAGER
SCLK
MCLKO
nECS
tNECS
tNECS
tACC
tCOH
tACS
tNWBE
tNWBE
nWBE
Address
Data
tADDRd
Addr
Data
tWDd
tWDh
nEWAIT
tACS = 1 (1 cycle)
tCOS = 0 (0 cycle)
tACC = 3 (4 cycles)
tCOH = 1 (1 cycle)
Figure 4-15. External I/O Write Timing 2
4-31
SYSTEM MANAGER
S3C4510B
SCLK
MCLKO
tNECS
tNECS
tCOH
tACC
tACS
nECS
tNWBE
tNWBE
nWBE
Address
Data
tCOS
tADDRd
Addr
Data
tWDd
tWDh
tWs
tWh
nEWAIT
tACS = 1 (1 cycle)
tCOS = 1 (1 cycle)
tACC = 1 (2 cycles)
tCOH = 1 (1 cycle)
Figure 4-16. External I/O Write Timing with nEWAIT
4-32
S3C4510B
SYSTEM MANAGER
DATA BUS WIDTH REGISTER (EXTDBWTH)
The S3C4510B has interfaces for 8/16/32-bit external ROMs, SRAMs, flash memories, DRAMs, SDRAMs, and
external I/O ports. Using data bus width register, you can set the data bus width that is required for specific
external memory and external I/O banks.
NOTE
In Figure 4-20, the term "Disable" means that the S3C4510B does not generate the access signal for the
corresponding external I/O bank.
Table 4-20. EXTDBWTH Register Description
Registers
Offset
R/W
Description
Reset Value
EXTDBWTH
0x3010
R/W
Data bus width of each bank
0x00000000
4-33
SYSTEM MANAGER
S3C4510B
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8 7 6 5 4 3 2 1 0
EXTDBWTH
0 0 0
0 DSX3 DSX2 DSX1 DSX0 DSD3 DSD2 DSD1 DSD0 DSR5 DSR4 DSR3 DSR2 DSR1 DSR0
[1:0] Data bus width for ROM/SRAM/FLASH bank 0 (DSR0)
DSR0 is read-only data at the B0SIZE [1:0] pins. DSR0 is used as read-only
because ROM/SRAM/FLASH bank 0 is used to boot the ROM while the data
bus width for ROM/SRAM/FLASH bank 0 is set using B0SIZE [1:0].
00 = Not permitted
01 = Byte (8 bits)
10 = Half-word (16 bits)
11 = Word (32 bits)
[3:2] Data bus width for ROM/SRAM/FLASH bank 1 (DSR1)
[5:4] DSR2, [7:6] DSR3, [9:8] DSR4, [11:10] DSR5
00 = Disable
01 = Byte (8 bits)
10 = Half- word (16 bits)
11 = Word (32 bits)
[13:12] Data bus width for DRAM bank 0 (DSD0)
[15:14] DSD1, [17:16] DSD2, [19:18] DSD3
00 = Disable
01 = Byte (8 bits)
10 = Half-word (16 bits)
11 = Word (32 bits)
[21:20] Data bus width for external I/O bank 0 (DSX0)
[23:22] DSX1, [25:24] DSX2, [27:26] DSX3
00 = Dissable
01 = Byte (8 bits)
10 = Half-word (16 bits)
11 = Word (32 bits)
NOTE:
When you select "Disable", the assigned external I/O
bank access signal is not generated.
Figure 4-17. Data Bus Width Register (EXTDBWTH)
4-34
S3C4510B
SYSTEM MANAGER
ROM/SRAM/FLASH CONTROL REGISTERS (ROMCON)
The System Manager has six control registers for ROM, SRAM, and flash memory (see Table 4-21). These
registers correspond to the up to six ROM/SRAM/Flash banks that are supported by S3C4510B.
For ROM/SRAM/Flash bank 0, the external data bus width is determined by the signal at the B0SIZE[1:0] pins:
When B0SIZE[1:0] = "01", the external bus width for ROM/SRAM/Flash bank 0 is 8 bits.
When B0SIZE[1:0] = "10", the external bus width for ROM/SRAM/Flash bank 0 is 16 bits.
When B0SIZE[1:0] = "11", the external bus width for ROM/SRAM/Flash bank 0 is 32 bits.
You can determine the start address of a special register's bank by the value of the corresponding "special
register bank base pointer". The control register's physical address is always the sum of the register's bank base
pointer plus the register's offset address.(For example, base pointer is 0x3ff0000 and ROMCON0’s offset is
0x3014. Then ROMCON0’s physical address becomes 0x3ff3014.)
NOTE
If you attach SRAM to a ROM/SRAM/Flash bank, you must set the page mode configuration bits,
ROMCONn[1:0], in the corresponding control register to "00" (normal ROM).
Table 4-21. ROM/SRAM/Flash Control Register Description
Registers
ROMCON0
ROMCON1
ROMCON2
ROMCON3
ROMCON4
ROMCON5
Offset
0x3014
0x3018
0x301C
0x3020
0x3024
0x3028
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Description
Reset Value
0x20000060
0x00000060
0x00000060
0x00000060
0x00000060
0x00000060
ROM/SRAM/Flash bank 0 control register
ROM/SRAM/Flash bank 1 control register
ROM/SRAM/Flash bank 2 control register
ROM/SRAM/Flash bank 3 control register
ROM/SRAM/Flash bank 4 control register
ROM/SRAM/Flash bank 5 control register
4-35
SYSTEM MANAGER
S3C4510B
31 30 29
20 19
10 9
8
7
6
4
3
2
1
0
ROM/SRAM/Flash Bank #
Next Pointer
ROM/SRAM/Flash Bank #
Base Pointer
0
0
0
0
0
tACC
tPA PMC
[1:0] Page mode configuration (PMC)
00 = Normal ROM
01 = 4-word page
10 = 8-word page
11 = 16-word page
[3:2] Page address access time (tPA)
00 = 5 cycles
01 = 2 cycles
10 = 3 cycles
11 = 4 cycles
[6:4] Programmable access cycle (tACC)
000 = Disable bank
010 = 3 cycle
110 = 7 cycle
001 = 2 cycles
011 = 4 cycles
111 = Reserved
[19:10] ROM/SRAM/Flash bank # base pointer
This value is the start address of the ROM/SRAM/Flash bank #.
The start address is calculated as ROM/SRAM/FLASH bank #
base pointer << 16.
[29:20] ROM/SRAM/FLASH bank # next pointer
This value is the current bank end address << 16 + 1.
Figure 4-18. ROM/SRAM/FLASH Control Registers (ROMCON0–ROMCON5)
4-36
S3C4510B
SYSTEM MANAGER
SCLK
MCLKO
tNRCS
tNROE
tADDRd
tNRCS
tACC
nRCS
nOE
tADDRh
Addr
Address
Data
tRDs
tRDh
Data
Data Fetch
Point
tACC = 4 (5 cycles)
Figure 4-19. ROM/SRAM/Flash Read Access Timing
4-37
SYSTEM MANAGER
S3C4510B
SCLK
MCLKO
tNRCS
tNROE
tNRCS
tNROE
tPA
tPA
tPA
tACC
nRCS
nOE
tADDRd
Addr
Addr + 1
Data
Addr + 2
Data
Addr + 3
Data
Address
Data
tRDh
tRDh
tRDh
tRDh
Data
Data Fetch
Data Fetch
Data Fetch
Data Fetch
tACC = 2 (3 cycles)
tPA = 1 (2 cycles)
PMC = 1 (4 word page)
Figure 4-20. ROM/SRAM/Flash Page Read Access Timing
4-38
S3C4510B
SYSTEM MANAGER
SCLK
MCLKO
tNRCS
tNRCS
tACC
nRCS
nWBE
tNWBE
tNWBE
tADDRd
Address
Data
Addr
tWDd
Data
tACC = 4 (5 cycles)
Figure 4-21. ROM/SRAM/Flash Write Access Timing
4-39
SYSTEM MANAGER
S3C4510B
SCLK
MCLKO
tNRCS
tNRCS
tACC
tPA
nRCS
nWBE
tNWBE
tNWBE
tADDRd
tADDRh
tADDRd
Addr
Addr + 1
Data
Address
Data
Data
tACC = 2 (3 cycles)
tPA = 1 (2 cycles)
PMC = 1 (4 word page)
Figure 4-22. ROM/SRAM/Flash Page Write Access Timing
4-40
S3C4510B
SYSTEM MANAGER
SCLK
MCLKO
tNRCS
tNRCS
NOTE 1
tACC
tPA (or tACC)
nRCS
nWBE
nOE
tNWBE
tNWBE
tNROE
tNROE
tADDRd
tADDRd
tADDRh
Addr
Addr + 1
Address
Data
Data
Data
Data Fetch
tACC = 2 (3 cycles)
tPA = 1 (2 cycles)
PMC = 1(4 word page)
NOTE:
Page hit case: tPA
Page miss case: tACC
Figure 4-23. ROM/SRAM/Flash Read and Write Access Timing
4-41
SYSTEM MANAGER
S3C4510B
SCLK
MCLKO
tNRCS
tNRCS
tACC
tPA
nRCS
nWBE
nOE
tNWBE
tNWBE
tNROE
tNROE
tADDRh
tADDRd
tADDRd
Addr
Addr + 1
Address
Data
Data
Data
Figure 4-24. ROM/SRAM/Flash Write and Read Access Timing
4-42
S3C4510B
SYSTEM MANAGER
ROM BANK 5 ADDRESS/DATA MULTIPLEXED BUS
Overview
The S3C4510B has separate address and data bus. S3C4510B supports multiplexed address/data bus for low
cost chips which require multiplexed bus. To support this feature, the S3C4510B has one special bank (ROM
bank 5) which can support address/data multiplexed bus and 4-data burst access by GDMA. For this feature, you
should set the MUX enable bit and wait enable bit of CLKCON register.
You can also use ROM bank 5 as normal ROM bank by clearing MUX enable bit of CLKCON register.
When you set the wait enable bit in the CLKCON register, wait cycle can be added by nEWAIT pin for ROM bank
5. Other ROM banks except ROM bank 5 has no effects. nEWAIT pin also can be used to add wait cycle for EXT
I/O bank regardless of the wait enable bit.
Random Access by CPU
At the first cycle of ROM bank 5, address comes out from data bus. Therefore, any device which is connected to
the ROM bank 5 can get address. The rest cycle is for data. As the S3C4510B has not a dedicated address
strobe signal for address phase in the data burst, you should generate address strobe signal in the application
device.
Four-data Burst Access by GDMA
When you set FB (4-data burst enable) bit in the GDMACON register, the GDMA requests 4-data burst access.
When you access ROM bank 5 by 4-data burst mode, the multiplexed ROM bank 5 bus has only one address
phase. Therefore, you should internally calculate the address at the data phase. To notify the 4-data burst mode
to ROM bank 5 device, the ADDR[21] remains "1" during address phase.
4-43
SYSTEM MANAGER
S3C4510B
SCLK
MCLKO
tNRCS
tNROE
tNRCS
tNROE
tACC
nRCS[5]
nOE
nWBE
tADDRd
Addr
Address
Data
tAC
Addr
Data
Address
Cycle
Data Cycle
nEWAIT
1 wait
Data Read
Point
tAC = 0 (1 cycle)
tACC = 1 (2 cycles)
MUX BUS Enable
Figure 4-25. ROM/SRAM/FLASH Bank 5 random Read with nEWAIT Access Timing
4-44
S3C4510B
SYSTEM MANAGER
SCLK
MCLKO
nRCS[5]
tNRCS
tNROE
tNRCS
tNROE
tACC
tACC
tACC
tACC
nOE
nWBE
tADDRd
Addr 0
Addr 1
Data 1
Addr 3
Address
Data
Addr 2
Data 2
tAC
Data 3
Data 0
Addr
Address
Cycle
Data Cycle
nEWAIT
tAC = 0 (1 cycle)
tACC = 1 (2 cycles)
MUX BUS Enable
Figure 4-26. ROM/SRAM/FLASH Bank 5 four word burst Read Access Timing When GDMA Request
4-45
SYSTEM MANAGER
S3C4510B
SCLK
MCLKO
tNRCS
tNRCS
tACC
nRCS[5]
nOE
tNWBE
tNWBE
nWBE
tADDRd
Addr
Address
Data
tAC
Addr
Data
Address
Cycle
Data Cycle
nEWAIT
1 Wait
tAC = 0 (1 cycle)
tACC = 1 (2 cycles)
MUX BUS Enable
Figure 4-27. ROM/SRAM/FLASH Bank 5 Write Timing with nEWAIT Access Timing
4-46
S3C4510B
SYSTEM MANAGER
SCLK
MCLKO
tNRCS
tNRCS
tACC
tACC
tACC
tACC
nRCS[5]
nOE
tNWBE
tNWBE
nWBE
tADDRd
Addr 0
Addr 1
Addr 2
Addr 3
Address
Data
tAC
Data 0
Data 1
Data 2
Data 3
Addr
Address
Cycle
Data Cycle
nEWAIT
tAC = 0 (1 cycle)
tACC = 1 (2 cycles)
MUX BUS Enable
Figure 4-28. ROM/SRAM/FLASH Bank5 Four-data Burst Mode Write Timing When GDMA Requests
4-47
SYSTEM MANAGER
S3C4510B
DRAM CONTROL REGISTERS
The System Manager has four DRAM control registers, DRAMCON0–DRAMCON3. These registers correspond
to the up to four DRAM banks that are supported by S3C4510B. A fifth register, REFEXTCON, is used to set the
base pointer for external I/O bank 0.
S3C4510B supports EDO, normal, Synchronous DRAM(SDRAM). SDRAM mode can be selected by setting
SYSCFG[31]. If this bit is set to '1', all DRAM banks are selected SDRAM. Otherwise, EDO/FP DRAM banks are
selected.
Table 4-22. DRAM and External I/O Control Register Description
Registers
DRAMCON0
DRAMCON1
DRAMCON2
DRAMCON3
REFEXTCON
Offset
0x302C
0x3030
0x3034
0x3038
0x303C
R/W
R/W
R/W
R/W
R/W
R/W
Description
Reset Value
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
DRAM bank 0 control register
DRAM bank 1 control register
DRAM bank 2 control register
DRAM bank 3 control register
Refresh and external I/O control register
4-48
S3C4510B
SYSTEM MANAGER
31 30 29
20 19
10 9
8
7
6
4
3
2
1
0
t
R
C
t
C
P
E
D
O
DRAM Bank # Next Pointer
DRAM Bank # Base Pointer
DRAMCON# CAN
tRP
Reserve
tCS
[0] EDO mode (EDO)
0 = Normal DRAM (Fast page mode DRAM)
1 = EDO DRAM
[2:1] CAS strobe time (tCS) (note)
00 = 1 cycle
01 = 2 cycles
10 = 3 cycles
11 = 4 cycles
[3:3] CAS pre-charge time (tCP)
0 = 1 cycle
1 = 2 cycles
[6:4] Reserved
These bits default value is 000. But, you must set to 001.
[7] RAS to CAS delay (tRC or tRCD)
0 = 1 cycle
1 = 2 cycles
[9:8] RAS pre-charge time (tRP)
00 = 1 cycle
10 = 3 cycles
01 = 2 cycles
11 = 4 cycles
[19:10] DRAM bank # base pointer
This value indicates the start address of DRAM bank #. The start address is
calculated as RAM bank # base pointer << 16
[29:20] DRAM bank # next pointer
This value is the current bank end address << 16 + 1
[31:30] Number of column address bits in DRAM bank # (CAN)
00 = 8 bits
01 = 9 bits
10 = 10 bits
11 = 11 bits
NOTE:
In SDRAM mode, this bit affect SDRAM cycle.
tCS value[1]: 0 = 1 cycle
1 = 2 cycle
Figure 4-29. DRAM Control Registers (DRAMCON–DRAMCON3)
4-49
SYSTEM MANAGER
S3C4510B
SCLK
MCLKO
tNRASr
tNRASf
tCS
tCP
tCS
tRP
nRAS
nCAS
tNCASf
tNCASr
tRC
tNROE
tNROE
nOE
nDWE
tADDRd
Row
Addr
Column Addr
(Same page)
Column Addr
Address
Data
Data
Data
Data Fetch
Data Fetch
(Normal DRAM)
(Normal DRAM)
Data
Data
Data Fetch
Data Fetch
(EDO DRAM)
(EDO DRAM)
tRP = 0 (1 cycle)
tCS = 1 (2 cycles)
tCP = 0 (1 cycle)
tRC = 0 (1 cycle)
Figure 4-30. EDO/FP DRAM Bank Read Timing (Page Mode)
4-50
S3C4510B
SYSTEM MANAGER
SCLK
MCLKO
tNRASr
tNRASf
tCS
tCP
tCS
nRAS
nCAS
tRP
tNCASwf
tNCASwr
tNDWE
tRC
tNDWE
nDWE
nOE
tADDRd
Row
Addr
Column Addr
(Same page)
Address
Data
Column Addr
Data
Data
tRP = 0 (1 cycle)
tCS = 1 (2 cycles)
tCP = 0 (1 cycle)
tRC = 0 (1 cycle)
Figure 4-31. EDO/FP DRAM Bank Write Timing (Page Mode)
4-51
SYSTEM MANAGER
S3C4510B
SCLK
MCLKO
tNRASr
tNRASf
tCS
tCP
tCS
nRAS
nCAS
tRP
tNCASf
tNCASwr
tNCASwf
tNCASr
tRC
tNROE
tNROE
nOE
tNDWE
tNDWE
nDWE
tADDRd
Row
Addr
Column Addr
(Same page)
Address
Data
Column Addr
Data
tWDDd
tWDDh
Data
Data Fetch
(Normal DRAM)
tRP = 0 (1 cycle)
tCS = 1 (2 cycles)
tCP = 0 (1 cycle)
tRC = 0 (1 cycle)
Data
Data Fetch
(EDO DRAM)
Figure 4-32. EDO/FP DRAM Bank Read and Write Timing (Page Mode)
4-52
S3C4510B
SYSTEM MANAGER
SCLK
MCLKO
tNRASr
tNRASf
tCS
tCP
tCS
nRAS
nCAS
tRP
tNCASf
tNCASwr
tNCASwf
tNCASr
tRC
tNROE
tNROE
nOE
tNDWE
tNDWE
nDWE
tADDRd
Row
Addr
Column Addr
(Same page)
Address
Data
Column Addr
tWDDd
tWDDh
Data
Data
Data Read
Point
tRP = 0 (1 cycle)
tCS = 1 (2 cycles)
tCP = 0 (1 cycle)
tRC = 0 (1 cycle)
Normal DRAM
Figure 4-33. EDO/FP DRAM Bank Write and Read Timing (Page Mode)
4-53
SYSTEM MANAGER
S3C4510B
Mode
Register Set
(MRS)
Precharge
(All banks)
Auto
Refresh
Auto
Refresh
200 us
SCLK
MCLKO
CKE
High level is necessary.
nSDCS
nSDRAS
nSDCAS
ADDR
BA
Key
A10/AP
nDWE
DQM
RFU
TM
A8 A7
0 0
CAS Latency
BT
A3
0
Burst Length
A2 A1 A0
0 0 0
KEY
A9
0
A6 A5 A4
0 1 0
Figure 4-34. SDRAM Power-up Sequence
4-54
S3C4510B
SYSTEM MANAGER
1
2
3
4
5
6
7
8
9
10
11
12
13
SCLK
MCLKO
CKE
nSDCS
tRP
nSDRAS
tRCD
nSDCAS
ADDR
Col2
Col1
Row
Col0
(1)
nDWE
DATA
Rd
Rd
Wd
(2)
(3)
0xF
0x0
0xF
0x0
0xF
DQM
Precharge
(All banks)
Row
Active
Read
Fetch
Write Read
Fetch
NOTES:
1. There is minimum 1 cycle gap between data-in and data-out of
SDRAM to prevent bus confliction.
2. All DQM signals go to zero during read operation.
3. Only valid signals go to zero during write operation.
Figure 4-35. Non-burst, Read-Write-Read Cycles @CAS Latency = 2, Burst Length = 1
4-55
SYSTEM MANAGER
S3C4510B
DRAM INTERFACE FEATURES
The S3C4510B provides a fully programmable external DRAM interface. You can easily modify the
characteristics of this interface by manipulating the corresponding DRAM control registers. Programmable
features include
·
·
·
·
·
External data bus width
Control fast page or EDO mode by DRAMCON[0]
Select fast page/EDO mode or SDRAM mode by SYSCFG
Number of access cycles for each DRAM bank, and
CAS strobe time, CAS precharge time, RAS to CAS delay, RAS pre-charge time
The refresh and external I/O control register, REFEXTCON, controls DRAM refresh operations and external I/O
bank accesses. The S3C4510B eliminates the need for an external refresh signal by automatically issuing an
internal CAS-before-RAS refresh or auto-refresh control signal.
The S3C4510B generates row and column addresses for DRAM accesses with 23-bit internal address bus. It also
supports symmetric or asymmetric DRAM addressing by changing the number of column address lines from 8 to
11.
EDO Mode DRAM Accesses
The timing for accessing a DRAM in EDO mode is comparable to DRAM accesses in normal fast page mode.
However, in EDO mode, the S3C4510B CPU fetches data (when read) one-half clock later than in normal fast
page mode. This is possible because EDO mode can validate the data even if CAS goes High when RAS is Low.
In this way, gives the CPU sufficient time to access and latch the data so that the overall memory access cycle
time can be reduced.
Synchronous DRAM Accesses
Synchronous DRAM interface features are as follows:
·
MRS cycle with address key program
— CAS latency (2 cycles)
— Burst length (1)
— Burst type (Sequential)
·
·
Auto refresh
SDRAM interface signal: CKE, SDCLK, nSDCS[3:0], nSDCAS, nSDRAS, DQM[3:0], ADDR[10]/AP
The address bits except row and column address among the 23-bit internal address bus can be assigned to Bank
select address(BA) for SDRAM.
See the SDRAM interface example, Figure 4-36.
4-56
S3C4510B
SYSTEM MANAGER
Available Samsung SDRAM Components for S3C4510B
Components
S3C4510B can support below SDRAM configuration for 1 bank.
·
·
·
·
·
2MBytes to 1 bank ® 1 ´ (2Mx32 with 4banks)
4MBytes to 1 bank ® 2 ´ (1Mx16 with 2banks)
8MBytes to 1 bank ® 4 ´ (2Mx8 with 2banks)
16MBytes to 1bank ® 2 ´ (4Mx16 with 2/4banks)
32MBytes to 1bank ® 4 ´ (8Mx8 with 2/4banks)
You can select any combination among them.
SDRAM components that are available are as follow.
x4 SDRAM whose capacity is larger than 16M SDRAM is not supported at S3C4510B.
16M bit SDRAM
— 4Mx4 with 2banks (Supported)
— 2Mx8 with 2banks (Supported)
— 1Mx16 with 2banks (Supported)
RA0–RA10, CA0–CA9
RA0–RA10, CA0–CA8
RA0–RA10, CA0–CA7
64M bit 2Banks SDRAM
— 16Mx4 with 2banks (not supported)
— 8Mx8 with 2banks (supported)
— 4Mx16 with 2banks (supported)
RA0–RA12, CA0–CA9
RA0–RA12, CA0–CA8
RA0–RA12, CA0–CA7
64M bit 4Banks SDRAM
— 16Mx4 with 4banks (not supported)
— 8Mx8 with 4banks (supported)
— 4Mx16 with 4banks (supported)
RA0–RA11, CA0–CA9
RA0–RA11, CA0–CA8
RA0–RA11, CA0–CA7
2Mx32 (64M bit) SDRAM
— 2Mx32 with 4banks (supported)
RA0–RA10, CA0–CA7
100 Pin DIMM Module SDRAM
KMM330S104CT
— 1Mx32 based on 2 1Mx16 2banks components
RA0–RA10, CA0–CA7
RA0–RA10, CA0–CA7
RA0–RA11, CA0–CA7
RA0–RA11, CA0–CA7
KMM330S204CT
— 4Mx32 based on 4 1Mx16 2banks components
KMM330S2424CT
— 4Mx32 based on 2 4Mx16 4banks componets
KMM330S824CT
— 8Mx32 based on 4 4Mx16 4banks componets
4-57
SYSTEM MANAGER
S3C4510B
Relationship Between CAN (Column Address Number) and Address MUX Output for SDRAM
Table 4-23. CAN and Address MUX Output
CAN
Output
Timing
External Address Pins (ADDR)
[21:15]
14
13
12
11
10
9
8
7-0
00
Column
address
x
A22
A21
A20
A19
A10/AP
A9
A8
A7-A0
Row
address
x
x
x
x
x
A22
0
A21
A22
A22
0
A20
A21
A21
A22
A22
A19
A20
A20
A21
A21
A18
A10/AP
A19
A17
A9
A16
A8
A15-A8
A7-A0
01
10
Column
address
Row
address
0
A18
A9
A17
A8
A16-A9
A7-A0
Column
address
0
A10/AP
A20
Row
0
0
A19
A18
A17-A10
address
NOTES:
1. A22 to A0 depends on external bus width. In case of x32 memory, A[22:0] is word address.
2. A[22:0] consists of: Bank Address + Valid Row Address + Valid Column Address
DRAM BANK SPACE
The S3C4510B DRAM interface supports four DRAM banks. Each bank can have a different configuration. You
use the DRAM control registers, DRAMCON0-DRAMCON3, to program the DRAM access cycles and memory
bank locations.
Each DRAM control register has two 10-bit address pointers, one base pointer and one next pointer, to denote the
start and end address of each DRAM bank. The 10-bit pointer values are mapped to the address [25:16]. This
gives each bank address an offset value of 64 K bytes (16 bits). The next pointer value will be the DRAM bank's
end address + 1.
System Initialization Values
When the system is initialized, the four DRAM control registers are initialized to 00000000H, disabling all external
DRAMs.
4-58
S3C4510B
SYSTEM MANAGER
CLK
D3
D2
D1
D0
CS
CKE
RAS
CAS
WE
Address
DQM
DQ0-7
<3>
<2>
<1>
<0>
CLK
MCLKO/SDCLK
nRAS/nSDCS 0, 1, 2, 3
nCAS2/CKE
CS
CKE
RAS
CAS
WE
nCAS0/nSDRAS
nCAS1/nSDCAS
nDWE
S3C451B
Address
DQM
DQ0-7
ADDR[10:0]
nWBE[3:0]/DQM[3:0]
XDATA[31:0]
ADDR[11]
BA0
CLK
All
SDRAM's
BA pin
CS
CKE
RAS
CAS
WE
Address
DQM
DQ0-7
CLK
CS
CKE
RAS
CAS
WE
Address
DQM
DQ0-7
NOTE:
4 components have the following features:
1 M x 8 bit x 2 Banks 9 bit column, 11 bit row- address
Figure 4-36. SDRAM Application Example
4-59
SYSTEM MANAGER
S3C4510B
DRAM REFRESH AND EXTERNAL I/O CONTROL REGISTER
The S3C4510B DRAM interface supports the CAS-before-RAS (CBR) refresh mode for EDO/FP DRAM and
auto-refresh for SDRAM. Settings in the DRAM refresh and external I/O control register, REFEXTCON, control
DRAM refresh mode, refresh timings, and refresh intervals. REFEXTCON also contains the 10-bit base pointer
value for the external I/O bank 0.
NOTE
Whenever the S3C4510B CPU writes one of system manager registers, the validity of special register
field (that is, the VSF bit) is automatically cleared and the external bus is disabled. To reactivate external
bus, you must set the VSF bit to "1" using a STMIA instruction. It is recommended that programmers
always use STMIA instructions to write the 10 system manager special registers. The instruction used to
set the VSF bit should always be the last instruction in the register write sequence.
4-60
S3C4510B
SYSTEM MANAGER
31
21 20 19
17 16 15 14 13 12 11 10 9
0
t
R V
E S
N F
External I/O Bank 0
Base Pointer
C
REFEXTCON
Refresh Count Value
tCHR
0 0 0 0 0
S
R
[9:0] External I/O bank 0 base pointer (base address)
This value is the start address of I/O external I/O bank 0. Start address is defined as
external I/O bank 0 base pointer << 16. The end address of external I/O bank 0 is defined
as external I/O bank 0 base pointer >> 16 + 16 Kbytes - 1.
NOTE:
All external I/O banks are located in the continuous address space which
begins at the start address of external I/O bank 0. The size of each external I/O bank
is fixed at 16Kbytes. The start and end addresses of the other three external I/O banks
can be derived from the external I/O bank 0 base pointer value.
[15] Validity of spedial register field (VSF)
0 = Not accessible to memory bank
1 = Accessible to memory bank
[16] Refresh enable (REN)
0 = Disable DRAM refresh
1 = Enable DRAM refresh
[19:17] CAS hold time (tCHR)
ROW cycle time (tRC) (Note 1)
000 = 1 cycle
010 = 3 cycles
100 = 5 cycles
110 = Not used
001 = 2 cycles
011 = 4 cycles
101 = Not used (6 cycles)
111 = Not used
[20] CAS setup time (tCSR)(Note 2)
0 = 1 cycle
1 = 2 cycles
[31:21] Refresh count value (duration)
The refresh period is calculate as (211 - value + 1)/fMCK
NOTES:
1. In EDO/normal DRAM mode, CAS hold time can be
programmed upto 5 cycles. But in SDRAM mode, this
bit fields function are defined as ROW cycle time (tRC)
and can be programmed upto 6 cycles.
2. In SDRAM mode, this bit field is reserved.
Figure 4-37. DRAM Refresh and External I/O Control Register (REFEXTCON)
4-61
SYSTEM MANAGER
S3C4510B
External I/O Bank 3
External I/O Bank 2
External I/O Bank 1
External I/O Bank 0
Continuous 16 Kword address
space for 4 external I/O banks
End Address of
External I/O Bank 0
4 Kwords (fixed for all I/O banks)
Start Address of
External I/O Bank 0
Start address of external I/O bank n =
(External I/O bank 0 base pointer << 16) + 16 Kbytes x n
End address of external I/O bank n =
(External I/O bank 0 base pointer << 16) + 16 Kbytes x (n + 1) - 1
Where, n is an external I/O bank number (= 0, 1, 2, 3)
Figure 4-38. External I/O Bank Address Map
4-62
S3C4510B
SYSTEM MANAGER
SCLK
MCLKO
nRAS
nCAS
tCSR
tCHR
nDWE/
nOE
Address
Data
Figure 4-39. EDO/FP DRAM Refresh Timing
4-63
SYSTEM MANAGER
S3C4510B
SCLK
MCLKO
CKE
High level is necessary
nSDCS
nSDRAS
nSDCAS
nDWE
tRP
tRC
Precharge
(All banks)
Auto
Refresh
New
Command
Figure 4-40. Auto Refresh Cycle of SDRAM
NOTE
At auto-refresh cycle, DRAM bank0's tRP bit field is used as RAS pre-charge time parameter.
4-64
S3C4510B
UNIFIED INSTRUCTION/DATA CACHE
5
UNIFIED INSTRUCTION/DATA CACHE
OVERVIEW
The S3C4510B CPU has a unified internal 8K byte instruction/data cache. Using cache control register settings,
you can use part or all of this cache as internal SRAM. To raise the cache hit ratio, the cache is configured using
two-way, set-associative addressing. The replacement algorithm is pseudo-LRU (Least Recently Used).
The cache line size is four words (16 bytes). When a miss occurs, four words must be fetched consecutively from
external memory. Typically, RISC processors take advantage of unified instruction/data caches to improve
performance. Without an instruction cache, bottlenecks that occur during instruction fetches from external
memory may seriously degrade performance.
CACHE CONFIGURATION
The S3C4510B’s 4K byte, two-way set-associative instruction/data cache uses a 15-bit tag address for each set.
The CS bits (a 2-bit value) in tag memory stores information for cache replacement. When a reset occurs, the CS
value is "00", indicating that the contents of cache set 0 and cache set 1 are invalid. When the first cache fill
operation occurs while exiting from the reset operation, the CS value becomes "01" at the specified line to
indicate that only set 0 is valid. When the subsequent cache fill occurs, the CS value becomes "11" at the
specified line, indicating that the contents of both set 0 and set 1 are valid.
5-1
UNIFIED INSTRUCTION/DATA CACHE
S3C4510B
31 30 29 28 27 26 25
10 9
4
3 2 1 0
Tag Address (15-bit)
2-bit
Enable non-cacheable control
7 (8) bits
15 (14)
switch
15 (14)
100: Set 0 direct access
101: Set 1 direct access
110: TAG direct access
2
15 (14)
Height = 128 (256)
CS
Set 1 Tag
Set 0 Tag
7 (8)-bit
Decoder
Tag RAM (32-bit)
Set I Cache 1 = 4 instruction/data (128-bit)
Set I Cache 0 = 4 instruction/data (128-bit)
Instr3
Instr2
Instr1
Instr0
Instr3
Instr2
Instr1
Instr0
7 (8)-bit
Height =
128 (256)
32-bit
32-bit
2
32
32
2
32
(Set 0 Hit)
(Set 1 Hit)
Figure 5-1. Memory Configuration for 4-Kbyte (or 8-Kbyte) Cache
5-2
S3C4510B
UNIFIED INSTRUCTION/DATA CACHE
CACHE REPLACE OPERATIONS
When the contents of two sets are valid and when the content of the cache must be replaced due to a cache
miss, the CS value becomes "10" at specified line. This indicates that the content of set 0 (S0) was replaced.
When CS is "10" and when another replacement is required due to a cache miss, the content of set 1 (S1) is
replaced by changing the CS value to "01".
To summarise, at its normal steady state, the CS value is changed from "01" or "10" to "10" or "01". This
modification provides the information necessary to implement a 2-bit pseudo-LRU (Least Recently Used) cache
replacement policy.
Reset(/)
NVALID: 00
; Set 0, set 1 all invalid
miss
; Chahe miss occurs
S0 only: 01
; Set 0 = valid, set 1 = invalid
Status does not change on hit
Hit
miss
; Read miss
; AV_S1D = All valid and set 1 is dirty.
Dirty means to access just before;
status does not change on hit.
Miss or hit 1
Miss or hit 0
AV-S1D: 11
AV-S0D: 10
Hit 1
; AV_S0D = All valid and set 0 is dirty.
Hit 0
Figure 5-2. Cache Replace Algorithm State Diagram
5-3
UNIFIED INSTRUCTION/DATA CACHE
CACHE DISABLE/ENABLE
S3C4510B
To disable the cache disable entirely following a system reset, you must set SYSCFG[1] to "0". By setting the
cache mode bits, SYSCFG[5:4], you can specify a cache size of 0, 4, or 8K bytes. If you do not need the entire 8-
Kbyte area for cache, you can use the remaining area as normal internal SRAM. The start address of the internal
SRAM area is defined by writing an appropriate value to SYSCFG[15:6].
CACHE FLUSH OPERATION
To flush cache lines, you must write a zero to Tag memory bits 31 and 30, respectively.
The 4-Kbyte set 0 RAM area, 4-Kbyte set 1 RAM area, and the 1-Kbyte Tag RAM area (total 256 words) can be
accessed from locations 0x10000000H, 0x10800000H, and 0x11000000H, respectively. You can do this
independently of the current cache mode bit and cache enable bit settings.
Tag RAM is normally cleared by hardware following a power-on reset. However, if you change the cache or
memory bank configuration when the cache is being enabled, you will have to clear the Tag RAM area using
application software.
NON-CACHEABLE AREA CONTROL BIT
Although the cache affects the entire system memory, it is sometimes necessary to define non-cacheable areas
when the consistency of data stored in memory and the cache must be ensured. To support this, the S3C4510B
provides a non-cacheable area control bit in the address field, ADDR[26].
If ADDR[26] in the ROM/SRAM, flash memory, DRAM, or external I/O bank's access address is "0", then the
accessed data is cacheable. If the ADDR[26] value is "1", the accessed data is non-cacheable.
Cacheable Area
Non-cacheable Area
000_0000
400_0000
000_0000
Cacheable Area
000_FFFF
401_0000
401_FFFF
Non-cacheable
Area
16 M word
002_0000
3FF_FFFF
Cacheable Area
7FF_FFFF
3FF_FFFF
NOTE:
The non-cacheable area has the same space in memory
as the cacheable area. To access the non-cacheable
area, you can change the address of the space in memory
using non-cacheable control bit.
Figure 5-3. Non-Cacheable Area Control
NOTE
A SWAP command must be used within a non-cacheable area.
5-4
2
S3C4510B
I C BUS CONTROLLER
2
6
I C BUS CONTROLLER
OVERVIEW
The S3C4510B's internal IC bus (I2C-bus) controller has the following important features:
—
It requires only two bus lines, a serial data line (SDA) and a serial clock line (SCL). When the I2C-bus is free,
both lines are High level.
— Each device that is connected to the bus is software-addressable by a single master using a unique address.
slave relationships on the bus are constant. The bus master can be either a master-transmitter or a master-
receiver. The I2C bus controller supports only single master mode.
— It supports 8-bit, bi-directional, serial data transfers.
— The number of ICs that you can connect to the same I2C-bus is limited only by the maximum bus
capacitance of 400 pF.
Figure 6-1 shows a block diagram of the S3C4510B I2C-bus controller
Data
Control
Shift Buffer Register (IICBUF)
System Clock (fMCK)
SDA
SCL
Serial
Clock
Prescaler
SCL
Control 0
16
Prescaler Register (IICPS)
0
BUSY COND1 COND0
ACK
LRB
IEN
BF
Control Status Register (IICCON)
Figure 6-1. I2C BUS Block Diagram
6-1
2
I C BUS CONTROLLER
S3C4510B
FUNCTIONAL DESCRIPTION
The S3C4510B I2C bus controller is the master of the serial I2C-bus. Using a prescaler register, you can program
the serial clock frequency that is supplied to the I2C bus controller. The serial clock frequency is calculated as
follows:
MCLK / (16 ´ (prescaler register value + 1) + 3)
To initialize the serial I2C-bus, the programmer sends a start code by writing "01" to bits [5:4]of the control status
register, IICCON. The bus controller then sends the 7-bit slave address and a read/write control bit through shift
buffer register. The receiver sends an acknowledge by pulling the SDA line from high to low during a master SCL
pulse.
To continue the data write operation, you must set the BF bit in the control status register and then write the data
to the shift buffer register. Whenever the shift buffer register is read or written, the BF bit is cleared
automatically. For the consecutive read/write operations, you must set the ACK bit in the control status register.
For read operations, you can read the data after you have set the BF bit in the control status register. To signal
the end of the read operation, you can reset the ACK bit to inform the receiver/transmitter when the last byte is to
be written/read.
Following a read/write operation, you set IICCON[5:4] to "10" to generate a stop code. If you want to complete
another data transfer before issuing the Stop code, you can send the start code using the repeat start command
(with IICCON[5:4] = "11"). When the slave address and read/write control bit have been sent, and when the
receive acknowledge has been issued to control SCL timing, the data transfer is initiated.
6-2
2
S3C4510B
I C BUS CONTROLLER
I2C-BUS CONCEPTS
Basic Operation
The I2C-bus has two wires, a serial data line (SDL) and a serial clock line (SCL), to carry information between the
ICs connected to the bus. Each IC is recognized by a unique address and can operate as either a transmitter or
receiver, depending on the function of the specific ICs.
The I2C-bus is a multi-master bus. This means that more than one IC which is capable of controlling the bus can
be connected to it. data transfers proceed as follows:
Case 1: A master IC wants to send data to another IC (slave):
1. Master addresses slave
2. Master sends data to the slave (master is transmitter, slave is receiver)
3. Master terminates the data transfer
Case 2: A master IC wants to receive information from another IC (slave):
1. Master addresses slave
2. Master receives data from the slave (master is receiver, slave is transmitter)
3. Master terminates the data transfer
Even in case 2, the master IC must generate the timing signals and terminate the data transfer.
If two or more masters try to put information simultaneously onto the bus, the first master to issue a "1" when the
other issues a "0" will lose the bus arbitration. The clock signals used for arbitration are a synchronized
combination of the clocks generated by the bus masters using the wired-AND connection to the SCL line.
The master IC is always responsible for generating the clock signals on the I2C-bus. Bus clock signals from a
master can only be altered by 1) a slow slave IC which "stretches" the signal by temporarily holding the clock line
Low, or 2) by another master IC during arbitration.
General Characteristics
Both SDA and SCL are bi-directional lines which are connected to a positive supply voltage through a pull-up
resistor.
When the I2C-bus is free, the SDA and SCL lines are both high level. The output stages of I2C interfaces
connected to the bus have an open-drain or open-collector to perform the wired-AND function. Data on the I2C-
bus can be transferred at a rate up to 100 Kbits/s. The number of interfaces that can be connected to the bus is
solely dependent on the limiting bus capacitance of 400 pF.
Bit Transfers
Due to the variety of different ICs (CMOS, NMOS, and I2L, for example) which can be connected to the I2C-bus,
the levels of logic zero (low) and logic one (high) are not fixed and depend on the associated level of VDD. One
clock pulse is generated for each data bit that is transferred.
6-3
2
I C BUS CONTROLLER
S3C4510B
Data Validity
The data on the SDA line must be stable during the high period of the clock. The high or low state of the data line
can only change when clock signal on the SCL line is low.
Start and Stop Conditions
Start and stop conditions are always generated by the master. The bus is considered to be busy after the start
condition is generated. The bus is considered to be free again when a brief time interval has elapsed following
the Stop condition.
— Start condition: a High-to-Low transition of the SDA line while SCL is high.
— Stop condition: a Low-to-High transition of the SDA line while SCL is high.
SDA
SCL
1-7
8
9
1-7
DATA
8
9
1-7
DATA
8
9
S
Start
P
Stop
Condition
Address R/W
ACK
ACK
ACK
Condition
Figure 6-2. Start and Stop Conditions
6-4
2
S3C4510B
I C BUS CONTROLLER
DATA TRSANSFER OPERATIONS
Data Byte Format
Every data byte that is put on the SDA line must be 8 bits long. The number of bytes that can be transmitted per
transfer is unlimited. Each byte must be followed by an acknowledge bit. Data is transferred MSB-first.
If the receiver cannot receive another complete byte of data until it has performed some other function (such as
servicing an internal interrupt), it can hold the clock line SCL Low to force the transmitter into a wait state. The
data transfer then continues when the receiver is ready for another byte of data and releases the SCL line.
Acknowledge Procedure
Data transfer with acknowledge is obligatory. The acknowledge-related clock pulses must be generated by the
bus master. The transmitter releases the SDA line (High) during the acknowledge clock pulse.
The receiver must pull down the SDA line during the acknowledge pulse so that it remains stable low during the
High period of this clock pulse.
Usually, a receiver which has been addressed is obliged to generate an acknowledge after each byte is received.
When a slave receiver does not acknowledge from the slave address, the slave must leave the data line high.
The master can then generate a stop condition to abort the transfer.
If a slave receiver acknowledges the slave address, but later in the transfer cannot receive any more data bytes,
the master must again abort the transfer. This is indicated by the slave not generating the acknowledge on the
first byte to follow. The slave leaves the data line high and the master generates the stop condition.
If a master receiver is involved in a transfer, it must signal the end of data to the slave transmitter by not
generating an acknowledge on the last byte that was clocked out of the slave. The slave transmitter must then
release the data line to let the master generate the stop condition.
6-5
2
I C BUS CONTROLLER
S3C4510B
Data Transfer Format
Data transfers uses the format shown in Figure 6-3. After the start condition has been generated, a 7-bit slave
address is sent. The eighth bit is a data direction bit (R/W). A "0" direction bit indicates a transmission (Write)
and a "1" indicates a request for data (Read).
A data transfer is always terminated by a stop condition which is generated by the master. However, if a master
still wishes to communicate on the bus, it can generate another start condition and address another slave without
first generating a stop condition. This feature supports the use of various combinations of read/write formats for
data transfers.
Multiple Byte Slave Receiver Format:
S
Slave address
W A
Data 1 (8 bits)
A
A
Data 2
Data 2
A
A
Data M
Data M
A P
A P
Multiple Byte Slave Transmitter Format:
Slave address R A Data 1 (8 bits)
S
NOTE:
S (Start)
W (Write; bit value is 0)
R (Read; bit value is 1)
P (Stop),
A (Acknowledge; The ACK is first sent to the slave. Afterwards, the direction
depends on the data transfer direction. In other words, if the mater reads the data,
it sends the ACK.)
Figure 6-3. Data Transfer Format
6-6
2
S3C4510B
I C BUS CONTROLLER
I2C-Bus Addressing
The addressing procedure for the I2C-bus is such that the first byte after the start condition determines which
slave the master will select. Usually, this first byte immediately follows the start procedure.
An exception is the "general call" address which can address all ICs simultaneously. When this address is used,
all ICs should, in theory, respond with an acknowledge. However, ICs can also be made to ignore this address.
The second byte of the general call address then defines the action to be taken.
Definition of Bits in the First Data Byte
The first seven bits of the first data byte make up the slave address. The eighth bit is the LSB, or direction bit,
which determines the direction (R/W) of the message.
When an address is sent, each IC on the bus compares the first 7 bits received following start condition with its
own address. If the addresses match, the IC considers itself addressed by the master as a slave receiver or a
slave transmitter.
General Call Address
The general call address can be used to address every IC that connected to the I2C-bus. However, if an IC does
not need any of the data supplied within the general call structure, it can ignore this address by not
acknowledging it.
If an IC does require data from a general call address, it can then acknowledge this address and behave as a
slave receiver. The second and following bytes will be acknowledged by every slave receiver capable of handling
this data. A slave which cannot process one of these bytes must ignore it by not acknowledging. The meaning of
the general call address is always specified in the second byte.
Start Byte
Every data transfer is preceded by a start procedure:
— A start condition, S
— A start byte, "00000001"
— An acknowledge (ACK) clock pulse, and
— A repeated start condition, Sr
After the start condition (S) has been transmitted by a master which requires bus access, the start byte
("00000001") is transmitted. Another IC can therefore sample the SDA line at a low sampling rate until one of the
seven zeros in the start byte is detected. After it detects this low level on the SDA line, the IC can switch to a
higher sampling rate to find the repeated start condition (Sr) which is then used for synchronization. (A) hardware
receiver will reset upon receipt of the repeated start condition (Sr) and will therefore ignore the start byte.)
An acknowledge-related clock pulse is generated after the start byte. This is done only to conform with the byte
handling format used on the bus. No IC is allowed to acknowledge the start byte.
6-7
2
I C BUS CONTROLLER
S3C4510B
I2C BUS SPECIAL REGISTERS
The I2C-bus controller has three special registers: a control status register (IICCON), a prescaler register (IICPS),
and a shift buffer register (IICBUF).
Control Status Register (IICCON)
The control status register for the I2C-bus, IICCON, is described in Table 6-2.
Table 6-1. Control Status Register (IICCON)
Register
Offset Address
R/W
Description
Control status register
Rest Value
IICCON
0xf000
R/W
0x00000000
Table 6-2. IICCON Register Description
Bit Number
Bit Name
Description
[0]
Buffer flag (BF)
The BF bit is set when the buffer is empty in transmit mode or
when the buffer is full in receive mode. To clear the buffer, you
write a "0" to this bit. The BF bit is cleared automatically
whenever the IICBUF register is written or read. If you set BF bit
to one, the I2C -bus is stopped. To activate I2C-bus, you should
clear the BF bit to zero.
[1]
[2]
Interrupt enable (IEN)
Last received bit (LRB)
Setting the interrupt enable bit to "1" enables the I2C-bus
interrupt.
The LRB bit is read only. It holds the value of the last received bit
over the I2C-bus. Normally, this bit will be the value of the slave
acknowledgement. To check for slave acknowledgement, you
test the LRB.
[3]
Acknowledge enable
(ACK)
The ACK bit is normally set to "1". This causes the I2C-bus
controller to send an acknowledge automatically after each byte.
This bit must be "0" when the I2C-bus controller is operating in
receiver mode and requires no further data to be received from
the slave transmitter. This causes a negative acknowledge on the
I2C-bus, which halts further reception from the slave device.
[5:4]
[6]
COND1, COND0
Bus busy (BUSY)
These bits control the generation of the start, Stop, and repeat
Start conditions: "00" = no effect, "01" = start, "10" = stop, and
"11" = repeat start.
This bit is a read-only flag that indicates when the I2C-bus is in
use. A "1" indicates that the bus is busy. This bit is set or cleared
by a start or stop condition, respectively.
[7]
Reset
If "1" is written to the reset bit, the I2C-bus controller is reset to its
initial state.
[31:8]
Reserved
Not applicable.
6-8
2
S3C4510B
I C BUS CONTROLLER
31
9
8
7
6
5
4
3
2
1
0
R
E
S
E
T
C C
B
U
S
Y
O O A L
I
B
F
N N C R E
D D K B N
Reserved
1
0
[0] Buffer Flag (BF)
0 = Automatically cleared when the IICBUF register is written or read. To
manually clear the BF, write 0.
1 = Automatically set when the buffer is empty in transmit mode or when the
buffer is full in receive mode.
[1] Interrupt enable (IEN)
0 = Disable
1 = Enable; an interrupt is generated if the BF bit is 1.
[2] Last received bit (LRB)
Use this read-only status bit to theck for ACK signals from the receiver (slave), or
to monitor SDA operation of SDA when writing 11 to IICCON [5:4] for repeated
starts.
0 = The most recent SDA is low. (ACK is received)
1 = The most recent SDA is high. (ACK not received)
[3] Acknowledge enable (ACK)
Controls generation of an ACK signal in receive mode.
0 = Do not generate an ACK at 9th SCL (No more received data is required from
the slave)
1 = Generate an ACK signal at 9th SCL.
[5:4] COND 1 and COND 0
Generate a bus control such as start or stop.
00 = No effect.
01 = Generate start condition.
10 = Generate stop condition.
11 = SCL will be released to high level to generate repeated start condition.
[6] Bus busy (BUSY)
Data transmission is in progress on the IIC-bus.
0 = Bus is currently not in use. (not busy)
1 = Bus is in use. (busy)
[7] Reset
0 = Normal
1 = Reset the IIC-bus controller.
[31:8] Reserved
Figure 6-4. I2C Control Status Register
6-9
2
I C BUS CONTROLLER
S3C4510B
Shift Buffer Register (IICBUF)
The shift buffer register for the I2C-bus described in Table 6-4.
Table 6-3. IICBUF Register
R/W Description
R/W Shift buffer register
Register
Offset Address
Rest Value
Undefined
IICBUF
0xf004
Table 6-4. IICBUF Register Description
Description
Bit Number
Bit Name
[7:0]
Data
This data field acts as serial shift register and read buffer for
interfacing to the I2C-bus. All read and write operations to/from the
I2C-bus are done via this register. The IICBUF register is a
combination of a shift register and a data buffer. 8-bit parallel data is
always written to the shift register, and read form the data buffer. I2C-
bus data is always shifted in or out of the shift register.
[31:8]
Reserved
Not applicable.
Prescaler Register (IICPS)
The prescaler register for the I2C-bus is described in Table 6-6.
Table 6-5. IICPS Register
R/W Description
R/W Prescaler register
Register
Offset Address
Rest Value
IICPS
0xf008
0x00000000
Table 6-6. IICPS Register Description
Description
Bit Number
Bit Name
This prescaler value is used to generate the serial I2C-bus clock. The
system clock is divided by (16 x (prescaler value + 1) + 3) to make the
serial I2C clock. If the prescaler value is zero, the system clock is when
divided by 19 to make the serial I2C clock.
[15:0]
Prescaler value
[31:16]
Reserved
Not applicable.
6-10
2
S3C4510B
I C BUS CONTROLLER
Prescaler Counter Register (IICCNT)
The prescaler counter register for the I2C-bus is described in Table 6-8.
Table 6-7. IICCNT Register
Register
Offset Address
R/W
Description
Rest Value
IICCNT
0xf00c
R/W
Prescaler counter register
0x00000000
Table 6-8. IICCNT Register Description
Description
Bit Number
Bit Name
[15:0]
Counter value
This 16-bit value is the value of the prescaler counter. It is read (in test
mode only) to check the counter’s current value.
[31:16]
Reserved
Not applicable.
6-11
2
I C BUS CONTROLLER
S3C4510B
NOTES
6-12
S3C4510B
ETHERNET CONTROLLER
7
ETHERNET CONTROLLER
OVERVIEW
The S3C4510B has an ethernet controller which operates at either 100-Mbits or 10-Mbits per second in half-
duplex or full-duplex mode. In half-duplex mode, the controller supports the IEEE 802.3 carrier sense multiple
access with collision detection (CSMA/CD) protocol. In full-duplex mode, it supports the IEEE 802.3 MAC control
layer, including the pause operation for flow control.
The ethernet controller¢s MAC layer supports both the media independent interface (MII) and the buffered DMA
interface (BDI). The MAC layer itself consists of the receive and the transmit blocks, a flow control block, a
content addressable memory (CAM) for storing network addresses, and a number of command, status, and error
counter registers.
The MII supplies the transmit and receive clocks of 25 MHz for 100-Mbit/s operation or 2.5 MHz at the 10-Mbit/s
speed. The MII conforms to the ISO/IEC 802-3 standards for a media-independent layer which separates
physical layer issues from the MAC layer.
7-1
ETHERNET CONTROLLER
S3C4510B
Physical
Layer
BDMA+SBUS I/F
MAC
MAC Tx
BDMA Tx
Buffer
Controller
Buffer
Controller
BDMA Tx
Buffer
(64 Words)
MAC Tx
Buffer
(80 bytes)
8
8
32
Preamble/
Jam/Pad/CRC
Generator
32
M
I
I
Bus Arbiter/
Controller
MAC Rx
Buffer
(16 bytes)
B
D
I
/
S
y
s
t
e
m
10
M
b
p
s
MAC Rx
Buffer
Controller
BDMA Rx
Buffer
(64 Words)
32
M
D
I
32
32
BDMA Rx
Buffer
Controller
Address
CAM Interface
and Comparator
7
-
W
i
B
u
s
Flow
Controller
CAM Contents
Memory
(32-Words)
32
r
CRC
e
Checker
BDMA Control
and Status
Register
MAC Control
and Status
Register
Station
Manager
Figure 7-1. Ethernet System Flow Control
7-2
S3C4510B
ETHERNET CONTROLLER
FEATURES AND BENEFITS
The most important features and benefits of the S3C4510B ethernet controller are as follows:
— Cost-effective connection to an external RIC/Ethernet backbone
— Buffered DMA (BDMA) engine using burst mode
— BDMA Tx/Rx buffers (256 bytes/256 bytes)
— MAC Tx/Rx FIFOs (80 bytes/16 bytes) to support re-transmit after collision without DMA request and to
handle DMA latency
— Data alignment logic
— Endian translation
— Support for old and new media (compatible with existing 10-Mbit/s networks)
— 100-Mbit/s or 10-Mbits/s operation to increase price/performance options and to support phased conversions
— Full IEEE 802.3 compatibility for existing applications
— Media Independent interface (MII) or 7-wire interface
— Station management (STA) signaling for external physical layer configuration and link negotiation
— On-chip CAM (21 addresses)
— Full-duplex mode for doubled bandwidth
— Pause operation hardware support for full-duplex flow control
— Long packet mode for specialized environments
— Short packet mode for fast testing
— PAD generation for ease of processing and reduced processing time
7-3
ETHERNET CONTROLLER
S3C4510B
MAC FUNCTION BLOCKS
The major function blocks of the ethernet controller¢s MAC layer are described in Table 7-1 and Figure 7-1.
Table 7-1. MAC Function Block Descriptions
Function Block
Description
Media Independent
Interface (MII)
The interface between the physical layer and the transmit and receive blocks.
Transmit block
Moves the outgoing data from the transmit buffer to the MII. The transmit block
includes circuits for generating the CRC, checking parity, and generating
preamble or jam. The transmit block also has timers for back-off after collision
and for the interframe gap the follows a transmission.
Receive block
Accepts incoming data from the MII and stores it in the receive FIFO. The
receive block has logic for computing and checking the CRC value, generating
parity for data from the MII, and checking minimum and maximum packet
lengths. The receive block also has a content addressable memory (CAM) block
which provides for address lookup, and for acceptance or rejection for packets
based on their destination address.
Flow control block
Recognizes MAC control packets and supports the pause operation for full-duplex
links. The flow control block also supports generation of pause packets, and
provides timers and counters for pause control.
MAC control (command)
and status registers
Controls programmable options, including the enabling or disabling of signals
which notify the system when conditions occur. The status registers hold
information for error handling software, and the error counters accumulate
statistical information for network management software.
Loop-back circuit
Provides for MAC-layer testing in isolation from the MII and physical layer.
7-4
S3C4510B
ETHERNET CONTROLLER
Transmit Block
MAC
Transmit
FIFO
Tx_DB[7:9]
10
M
b
/
s
Preamble and
Jam Generator
TxD_10
(80 bytes)
Pad and CRC
Generator
Backoff
and
Intergap
Timer
RxD_10
I/F
MAC
Loop-back
Parity Check
TxD[3:0]
B
D
I
Flow Control
Rx_DB[7:0]
MAC
M
I
I
Receive
FIFO
(16 bytes)
Parity
Generator
RxD[3:0]
CRC and
CAM Filter
MDC
Receive Block
MII Station
Manager
MDIO
MAC Control and
Status Register
Figure 7-2. MAC Layer Flow Control Function Blocks
7-5
ETHERNET CONTROLLER
S3C4510B
MEDIA INDEPENDENT INTERFACE (MII)
Transmit and receive blocks both operate using the MII, which was developed by the IEEE802.3 task force on
100-Mbit/s ethernet. This interface has the following characteristics:
— Media independence
— Multi-vendor points of interoperability
— Supports connection of MAC layer and physical layer entity (PHY) devices
— Capable of supporting both 100-Mbit/s and 10-Mbit/s data rates
— Data and delimiters are synchronous to clock references
— Provides independent 4-bit wide transmit and receive data paths
— Uses TTL signal levels that are compatible with common digital CMOS ASIC processes
— Supports connection of PHY layer and station management (STA) devices
— Provides a simple management interface
— Capable of driving a limited length of shielded cable
PHYSICAL LAYER ENTITY (PHY)
The physical layer entity, or PHY, performs all of the decoding/encoding on incoming and outgoing data. The
manner of decoding and encoding (Manchester for 10BASE-T, 4B/5B for 100BASE-X, or 8B/6T for 100BASE-T4)
does not affect the MII. The MII provides the raw data it receives, starting with the preamble and ending with the
CRC. The MII expects raw data for transmission, also starting with the preamble and ending with the CRC. The
MAC layer also generates jam data and transmits it to the PHY.
BUFFERED DMA INTERFACE (BDI)
The buffered DMA interface (BDI) supports read and write operations across the system bus. Two eight-bit buses
transfer data with optional parity checking. The system interface initiates data transfers. The MAC-layer controller
responds with a ready signal to accept data for transmission, or to deliver data which has been received. An end-
of-frame signal indicates the boundary between packets.
7-6
S3C4510B
ETHERNET CONTROLLER
THE MAC TRANSMIT BLOCK
The MAC transmit block is responsible for transmitting data. It complies with the IEEE802.3 standard for carrier
sense multiple access with collision detection (CSMA/CD) protocol. The MAC transmit block consists of the
following sections:
— Transmit FIFO and controllers
— Preamble and jam generators
— Pad generator
— Parallel CRC generator
— Threshold logic and counters
— Back-off and retransmit timers
— Transmit state machine
Figure 7-3 shows the MAC transmit function blocks in detail.
Parity
Check
Preamble and
Tx_DB [7:0]
JAM generator
MAC
and PARITY
M
I
I
Transmit
FIFO
(80 x 9)
9
TxD [3:0]
9
8
a
n
d
PAD
Generator
Tx_CLK
CrS
CRC
Generator
Tx_EOF
Tx_wr#
Tx_rdy
B
D
I
Write FIFO
Controller
and Counter
10
M
b
y
t
Tx_er
Tx_en
Read FIFO
Controller
and Counter
Transmit
State
Matchine
e
Col
Threshold
Logic and
Counters
I/F
Back off and
Retransmit
Timers
SYS_CLK Domain
Tx_CLK Domain
Figure 7-3. MAC Transmit Function Blocks
7-7
ETHERNET CONTROLLER
S3C4510B
Transmit FIFO and Read/Write Controllers
The transmit FIFO has an 80-byte depth. An extra bit is associated with each data byte for parity checking. This
80-byte by 9-bit size allows the first 64 bytes of a data packet to be stored and retransmitted, without further
system involvement, in case of a collision. If no collision occurs and transmission is underway, the additional 16
bytes handle system latency and avoid FIFO under-run.
When the system interface has set the transmit enable bit in the appropriate control register, the transmit state
machine requests data from the BDI. The system controller then fetches data from the system memory.
The FIFO controller stores data in the transmit FIFO until the threshold for transmit data is satisfied. The FIFO
controller passes a handshaking signal to the transmit state machine, indicating that sufficient data is in the FIFO
to start the transmit operation. If the FIFO is not full, the FIFO controller issues a request to the BDI for more
data. The transmit state machine continues transmitting data until it detects the end-of-frame signal, which
signals the last byte. It then appends the calculated CRC to the end of the data (unless the CRC truncate bit in
the transmit control register is set). The packet transmit bit in the status register is set, generating an interrupt if it
is enabled.
The FIFO counters in this block (the Write counter) and the transmit FIFO counter of the transmit state machine
(the Read counter) co-ordinate their functions based on each other's count value, although they do have different
clock sources.
The FIFO controller stores parity bits with the data in the FIFO. It checks for parity and can halt transmission
after reading the data out of the FIFO and sending it for the CRC calculation. If a parity error occurs, the FIFO
controller sets an error status bit, generating an interrupt if it is enabled.
Preamble and Jam Generator
As soon as the transmit enable bit in the control register is set and there are eight bytes of data in the FIFO, the
transmit state machine starts the transmission by asserting the Tx_en signal and transmitting the preamble and
the start frame delimiter (SFD). In case there is a collision, it transmits a 32-bit string of "1s" after the preamble
as a jam pattern.
PAD Generator
If a short data packet is transmitted, the MAC will normally generate pad bytes to extend the packet to a
minimum of 64 bytes. The pad bytes consist entirely of "0" bits. A control bit is also used to suppress the
generation of pad bytes.
Parallel CRC Generator
The CRC generation of the outgoing data starts from the destination address and continues through the data
field. You can suppress CRC generation by setting the appropriate bit in the transmit control register. This is
useful in testing, for example, to force the transmission of a bad CRC in order to test error detection in the
receiver. It can also be useful in certain bridge or switch applications, where end-to-end CRC checking is desired.
7-8
S3C4510B
ETHERNET CONTROLLER
Threshold Logic and Counters
The transmit state machine uses a counter and logic to control the threshold of when transmission can begin.
before it attempts to initiate transmission, the MAC waits until eight bytes or a complete packet has been placed
in the transmit FIFO. This gives the DMA engine some latency without causing an underflow during transmission.
Back-Off and Retransmit Timers
When a collision is detected on the network, the transmitter block stops the transmission and starts a jamming
pattern to ensure that all the nodes detect the collision. After this, the transmitter waits for a minimum of 96 bit
times and then retransmits the data. After 16 attempts, the transmit state machine sets an error bit and
generates an interrupt, if enabled, to signify the failure to transmit a packet due to excessive collisions. It flushes
the FIFO, and the MAC is ready for the next packet.
Transmit Data Parity Checker
Data in the FIFO is odd-parity protected. When data is read for transmission, the transmit state machine checks
the parity. If a parity error is detected, the transmit data parity checker does the following:
— It stops transmission.
— It sets the parity error bit in the transmit status register.
— It generates an interrupt, if enabled.
Transmit State Machine
The transmit state machine is the central control logic for the transmit block. It controls the passing of signals, the
timers, and the posting of errors in the status registers.
7-9
ETHERNET CONTROLLER
S3C4510B
THE MAC RECEIVE BLOCK
The MAC receive block is responsible for receiving data. It complies with the IEEE802.3 standard for carrier
sense multiple access with collision detection (CSMA/CD) protocol.
After it receives a packet, the receive block checks for a number of error conditions: CRC errors, alignment
errors, and length errors. Several of these checks can be disabled by setting bits in the appropriate control
registers. depending on the CAM status, the destination address and the receive block may reject an otherwise
acceptable packet. The MAC receive block consists of the following units:
— Receive FIFO, FIFO controller, and counters
— Receive BDI state machine
— Threshold logic and counters
— CAM block for address recognition
— Parallel CRC checker
— Receive state machine
The main components of the receive block are shown in Figure 7-4.
Rx_DB [7:0]
and parity
RxD[3:0]
Rx_clk
MAC Receive
FIFO
9
(16X10)
Parity
Check
SFD
Detect
CAM
Checker
Read
address
Write address
/WE
CRC
Checker
Rx_DV
Rx_er
Receive
State
Machine
Write FIFO
controller
and counter
Write FIFO
controller
and counter
Rx_rd
Rx_rdy
Receive
BDI state
Machine
Rx_EOF
Thershold
logic and
counter
Rx_keep
Rx_toss
Rx_load
CAM_hit#
SYS_CLK Domain
Rx_CLK Domain
Figure 7-4. MAC Receive Function Blocks
7-10
S3C4510B
ETHERNET CONTROLLER
Receive FIFO Controller
The receive FIFO controller accepts data one byte at a time. Parity starts with the destination address. The
receive controller updates the counter with the number of bytes received. As the FIFO stores the data, the CAM
block checks the destination address against its stored address. If the CAM recognizes the address, the FIFO
continues receiving the packet. If the CAM block does not recognize the address and rejects the packet, the
receive block discards the packet and flushes the FIFO.
Address CAM and Address Recognition
The CAM block provides direct comparison address recognition. The CAM compares the destination address of
the received packet to stored addresses. If it finds a match, the receive state machine continues to receive the
packet. The CAM is organized to hold six-byte address entries. With its 32-word size, the CAM can store 21
address entries.
CAM address entries 0, 1, and 18 are used to send the pause control packet. To send a pause control packet,
you must write the destination address to CAM0, the source address to CAM1, and length/type, op-code, and
operand to the CAM18 entry. You must them write the MAC transmit control register to set the send pause
control bit. In addition, CAM19 and CAM20 can be used to construct a user-define control frame.
Parallel CRC Checker
The receive block computes a CRC across the data and the transmitted CRC, and then checks that the resulting
syndrome is valid. A parallel CRC checking scheme handles data arriving in 4-bit nibbles at 100 Mbps. To
support full-duplex operation, the receive and transmit blocks have independent CRC circuits.
Receive State Machine
In MII mode, the receive block receives data from the MII on the RxD[3:0] lines. This data is synchronized to
Rx_clk at 25 MHz or 2.5 MHz. In 7-wire mode, and at 10 MHz, data is received on the RxD_10 line only.
After it detects the preamble and SFD, the receive state machine arranges data in byte configurations, generates
parity, and stores the result in the receive FIFO one byte at a time. If the CAM block accepts the destination
address, the receive FIFO stores the rest of the packet. At the end of the reception, the receive block marks the
packet received by setting the appropriate bits in the receive status register. Any error in reception will reset the
FIFO and the state machine will wait for the end of the current packet. It will then idle while it is waiting for the
next preamble and SFD.
BDMA Interface Receive State Machine
The BDMA I/F receive state machine issues the Rx_rdy signal to request that the receive FIFO have data
whenever data is present in the receive FIFO. The last byte of the packet is signaled by asserting the Rx_EOF.
In case there are any errors during the reception, or if there is a CRC error at the end, the BDMA I/F receive
state machine asserts the Rx_toss signal to indicate that the received packet should be discarded.
7-11
ETHERNET CONTROLLER
S3C4510B
FLOW CONTROL BLOCK
The flow control block provides for the following functions:
— Recognition of MAC control frames received by the receive block
— Transmission of MAC control frames, even if transmitter is paused
— Timers and counters for pause operation
— Command and status register (CSR) interface
— Options for passing MAC control frames through to software drivers
The receive logic in the flow control block recognizes a MAC control frame as follows:
— The length/type field must have the special value specified for MAC control frames. The destination address
must be recognized by the CAM. The frame length must be 64 bytes, including CRC. The CRC must be
valid, and the frame must contain a valid pause op-code and operation.
— If the length/type field does not have the special value specified for MAC control frames, the MAC takes no
action, and the packet is treated as a normal packet. If the CAM does not recognize the destination address,
the MAC rejects the packet. If the packet length is not 64 bytes, including CRC, the MAC does not perform
the operation. The packet is then marked as a MAC control packet, and is passed forward to the software
drivers, if pass-through is enabled.
You can set control bits in the transmit status register to generate a Full-Duplex pause operation or other MAC
control functions, even if the transmitter itself is paused. Two timers and two corresponding CSR registers are
used during a pause operation. One timer/register pair is used when a received packet causes the transmitter to
pause. The other pair is used to approximate the pause status of the other end of the link, after the transmitter
sends a Pause command.
The command and status register (CSR) interface provides control and status bits within the transmit and receive
control registers and status registers. These lets you initiate the sending of a MAC control frame, enable and
disable MAC control functions, and read the values of the flow control counters.
Control bits are provided for processing MAC control frames entirely within the controller, or for passing MAC
control frames on to the software drivers. This lets you enable flow control by default even on software drivers
which are not otherwise "flow control aware".
7-12
S3C4510B
ETHERNET CONTROLLER
BUFFERED DMA INTERFACE
BUFFERED DMA (BDMA) CONTROL BLOCKS
The BDMA engine controls a transmit buffer and a receive buffer. The BDMA transmit buffer holds data and
status information for packets being transmitted. The BDMA receive buffer holds data and status information for
packets being received. Each FIFO has a control block which controls data being placed in, and removed from,
the buffers.
Half_full
Half_empty
SD [31:0]
nREQ_Tx
Rx Bus
Tx_clk
Tx_wr
BDMA
Tx
Buffer
(32 x 64)
HEAD Ptr
TAIL Ptr
SD[31:0]
nACK
Tx
Control
Machine
-
Request
BUS
Arbiter
Tx_rdy
S
Y
S
T
E
M
B
D
I
Half_full
Tx_Underflow
nREQ_Rx
nREQ
Tx_DB[7:0]
Tx widget
Big/little
Word-to-Byte
Converter
B
D
M
A
SA[25:0]
Data Swapper
Big/Little
Address
Generator
B
U
S
BDMA
Rx
Buffer
(33 x 64)
HEAD Ptr
TAIL Ptr
Rx_clk
Rx_rd
Rx Bus
Request
-
I/F
Rx
Control
Machine
Target Address
for Rx
I/F
Rx_rdy
RX_over flow
Half_empty
Rx_DB[7:0]
Byte-to-Word
Converter
Source Address
for Tx
Rx_Widget
Figure 7-5. BDMA Control Blocks
7-13
ETHERNET CONTROLLER
The Bus Arbiter
S3C4510B
The bus arbiter decides which of the BDMA buffer controllers, transmit (Tx) or receive (Rx), has the highest
priority for accessing the system bus. The prioritization is dynamic. The BDMA arbiter outputs a bus request
signal (nREQ) to the system manager when
— A buffer contains more words than the Rx burst size,
— An EOF (End of Frame) was saved to the buffer, or
— A buffer contains more free space than the Tx burst size.
After it receives a bus acknowledge signal (nACK) from the system manager, the BDMA bus arbiter determines
the correct bus access priority. If nREQ_Tx and nREQ_Rx were requested simultaneously, the bus arbiter
decodes the nACK signal using the following method:
switch (Half_empty, Half_full)
{ case 2'b01: nACK_Rx ¬ nACK
case 2'b10: nACK_Tx ¬ nACK
default: //case 2'b00 or 2'b11:
if (Rx buffsize (Head - Tail) < Tx buffsize) // Rx more urgent
nACK_Rx ¬ nACK
else nACK_Tx ¬ nACK}
7-14
S3C4510B
ETHERNET CONTROLLER
BDMA Bus Control Logic
The function blocks of the BDMA controller provide logic for controlling bus master read and write operations
across the system bus. This control logic supports the following operations:
— Burst size control, to optimize system bus utilization.
— Transmit threshold control (based on 1/8 of transmit buffer size) to match transmission latency to system bus
latency.
— Little-Endian byte swapping, to support the data transfer of Little-Endian memory usage for frame data.
— A transmit/receive alignment widget to circumvent word alignment restrictions.
In systems with an ATM LAN emulation or an MPOA interface, and in certain other systems as well, the
beginning of a packet should be placed on a byte or half-word boundary. You may not, however misalign the
BDMA transfer, as this would complicate the design of the DMA, and would degrade performance. To avoid this,
you can use an alignment widget between the BDMA buffer (word) and the MAC FIFO (byte).
In the receiver, the BDMA bus control logic inserts a programmable number of bytes (up to three) into the
received data stream while the preamble is being received. This adds some padding to the beginning of the
frame. This padding can then be used to solve alignment problems downstream, without having to use a copy of
the buffer. Because there is never more than three bytes, this feature does not degrade performance. Also,
because the data is inserted prior to the concatenation of bytes into words, it does not misalign the subsequent
DMA transfer.
The length of the alignment data is read from a control register. This length value should be set by software
immediately after the MAC module is reset, and it should not be modified.
You can use a corresponding transmit alignment widget to remove data from the buffer. In the simplest
implementation, the widget discards the first "n" bytes (up to three), where "n" is the value read from the transmit
frame descriptor which configures the transmit alignment widget.
MEMORY DATA STRUCTURES
The flow control 100-/10-Mbit/s ethernet controller uses three data structures to exchange control information and
data:
— Transmit frame descriptor
— Receive frame descriptor
— Frame data buffer
Each frame descriptor has the following elements:
— Frame start address
— Ownership bit
— Control field for transmitter
— Status field
— Frame length
— Next frame descriptor pointer
Figure 7-6 shows data structures of the transmit and receive frame descriptors.
7-15
ETHERNET CONTROLLER
S3C4510B
DATA FRAMES
The ownership bit in the MSB of the frame start address controls the owner of the descriptor. When the
ownership bit is "1", the BDMA controller owns the descriptor. When this bit is "0", the CPU owns the descriptor.
The owner of the descriptor always owns the associated data frame. (The descriptor's frame start address field
always points to this frame.)
As it receives the data frame, software sets the maximum frame size register in the BDMA block to the system
frame buffer size (typically, to 1536 or 2048). Software also sets the Rx frame descriptor start address register to
point to a chain of frame descriptors, all of which have their ownership bit set.
The BDMA engine can then be started to set the BDMA receive enable bit in the BDMARXCON register. When a
frame is received, it is copied into memory at the address specified by the Rx frame start address. Please note
that no configurable offset or page boundary calculation is required. The received frame is written into the frame
data buffer until the end of frame is reached, or until the length exceeds the configured maximum frame size.
If the entire frame is received successfully, the status bits in the frame descriptor are set to indicate this.
Otherwise, the status bits are set to indicate that an error occurred. The ownership bit in the frame start address
field is cleared and an interrupt may now be generated. The BDMA controller copies the next frame descriptor
register value into the Rx frame descriptor start address register. If the next frame descriptor address is null (0),
the BDMA simply halts, and all subsequent frames are dropped. Otherwise, the descriptor is read in, and the
BDMA controller starts again with the next frame, as described in the previous paragraph.
If the received frame size exceeds the maximum frame size, the data frame will be overwritten by the last word
of maximum frame. The overflow data is written to the Rx status bit [19] in the receive frame descriptor. When
the BDMA reads a descriptor, if the ownership bit is not set, it has two options:
— Skip to the next frame descriptor, or
— Generate an interrupt and halt the BDMA operation.
Transmit frame descriptors contain the following components:
— A four-byte pointer to the frame data
— Widget alignment control bits [6:5]
— Frame data pointer increment/decrement bit [4]
— Little-Endian control bit [3]
— Interrupt enable after transmit [2]
— No-CRC [1], and
— No-padding [0]
During transmission, the two-byte frame length at the Tx frame descriptor is moved into the BDMA internal Tx
register. After transmission, Tx status is saved in the Tx frame descriptor. The BDMA controller then updates the
next frame descriptor address register for the linked list structure.
When the Tx frame descriptor start address register points to the first frame buffer, transmitter starts transmitting
the frame data into the frame buffer memory.
7-16
S3C4510B
ETHERNET CONTROLLER
31 30
16 15
0
O
Frame Data Pointer
Reserved
Rx Status
Frame Length
Next Frame Descriptor Pointer
[31] Ownership bit (O)
0 = CPU
1 = BDMA
[30:0] Frame Data Pointer
Address of the frame data to be saved.
[15:0] Frame Length
The size of the received frame.
[31:16] Rx Status
The Rx status field of the receive frame is updated by the MAC after reception is
complete.
[31:0] Next frame descriptor pointer
Address of next frame descriptor.
Figure 7-6. Data Structure of Rx Frame Descriptor
7-17
ETHERNET CONTROLLER
S3C4510B
31 30
16 15
7 6
5 4
3
2
1
0
O
Frame Data Pointer
Reserved
WA A L
Frame Length
T
C P
Tx Status
Next Frame Descriptor Pointer
[0] No-padding mode (P)
0 = Padding mode 1 = No-padding mode
[1] No-CRC mode (C)
0 = CRC mode
1 = No-CRC mode
[2] MAC transmit interrupt enable after transmission of this frame (T)
0 = Disable 1 = Enable
[3] Little-Endian mode (L)
0 = Big-endian
1 = Little-endian
[4] Frame data pointer increment/decrement (A)
0 = Decrement
1 = Increment
[6:5] Widget alignment control (WA)
(Non-aligned data must be transmitted without alignment control.)
00 = No invalid bytes
10 = Two invalid bytes
01 = One invalid byte
11 = Three invalid bytes
[31] Ownership bit (0)
0 = CPU
1 = BDMA
[30:0] Frame data pointer
The address of the frame data to be transmitted.
[15:0] Frame length
The size of the transmit frame.
[31:16] Tx status
This Tx frame status field is updated by the MAC after transmission.
[31:0] Next frame descriptor pointer
The address of the next frame descriptor.
Figure 7-7. Data Structure of Tx Frame Descriptor
7-18
S3C4510B
ETHERNET CONTROLLER
Rx Status
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
R
x
H G
a
l
t
e
d
O
v
e
r
f
l
A R
L
o
n
g
E
r
C
R
l
i
x
1
0
S
t
C
t
i
R
c
v
R
x
p
a
r
I
n
t
R
x
O
v
o
o
d
C g
0
0
M 0 0 0
a
x
E
r
r
n
E
r
o
w
a
t
r
r
[19] Over maximum size (OvMax)
Set if the received frame data size exceeds the maximum frame size.
[21] Control received (CtlRcv)
Set if the received packet is a MAC control frame.
[22] Interrupt on receive (IntRx)
Set if reception of packet caused an interrupt condition. This includes Good
received, if the Engood bit, MACRXCON [14], is set.
[23] Receive 10 Mb/s status (Rx10stat)
Set if packet was received over the 7-wire interface. Reset if packet was received
over the MII.
[24] Alignment error (AlignErr)
Frame length in bits was not a multiple of eight and the CRC was invalid.
[25] CRC Error (CRCErr)
CRC at end of packet did not match the computed value, or else the PHY
asserted Rx_er during packet reception.
[26] Overflow error (Overflow)
The MAC receive FIFO was full when it needed to store a received byte.
[27] Long error (LongErr)
Received a frame longer than 1518 bytes. Not set if the long enable bit set to one
in the receive control register.
[29] Receive parity error (RxPar)
MAC receive FIFO has detected a parity error.
[30] Good received (Good)
Successfully received a packet with no errors. If EnGood = 1, an interrupt is
generated on each packet that is received successfully.
[31] Reception halted (RxHalted)
Reception interrupted by user clearing RxEN or setting Haltlmm in the MAC
control register.
Figure 7-8. Rx Descriptor Status Bits
7-19
ETHERNET CONTROLLER
S3C4510B
Tx Status
31 30 29 28 27 26 25 24 23 22 21 20 19
16
R
x
H C
a
l
t
e
d
L
a
t
e
C
o
l
T
x
D
e
f
P
a
u
s
e
d
E
x
C
o
l
T
x
p
a
r
S N D U
I
n
t
T
x
Q C e
n
d
e
r
o
m
p
E
r
r
a
r
r
f
e
r
TxCollCnt
e
r
l
l
[19:16] Transmit collision count (TxCollCnt)
Count of collisions during transmission of a single packet. After 16 collisions, TxColl
is zero, and ExColl is set.
[20] Excessive collision (ExColl)
16 collisions occured in the same packet.
[21] Transmit deferred (TxDefer)
[22] Paused
[23] Interrupt on transmit (IntTx)
Set if transmission of packet caused an interrupt condition. This includes the enable
completion (EnComp), MACTXCON [14], if enabled.
[24] Underrun (Under)
MAC transmit FIFO becomes empty during transmission.
[25] Deferral (Defer)
MAC defers for max_deferral 0.32768ms for 100Mbit/s or 3.27680ms for 10Mbit/s.
[26] No carrier (NCarr)
Carrier sense is not detected during the entire transmission of a packet
(from the SFD to the CRC).
[27] SQE error (SQErr)
After transmit frame, set if the fake collision (COL) signal did not come from the PHY
for 1.6 ms.
[28] Late collision (LateColl)
A collision occurred after 512 bit times (64 byte times)
[29] Transmit parity error (TxPar)
MAC transmit FIFO detected a parity error.
[30] Completion (Comp)
MAC complete a transmit or discard of one packet.
[31] Transmission halted (TxHalted)
Transmission halted by clearing RxEn or setting the Haltlmm in the MAC control
register. Or, an interrupt was generated by an error condition (not completion).
Figure 7-9. Tx Descriptor Status Bits
7-20
S3C4510B
ETHERNET CONTROLLER
Frame
Descriptor
Start Address
Register
Frame Data Pointer #1
Receive Frame
Maximum Size
Register
Frame Data #1
Unused
Status Frame Length
Next Frame Descriptor
(BDMARXLSZ)
Frame Data Pointer #2
Frame Data #2
Unused
BDMARXLSZ
BDMARXLSZ
Status Frame Length
Next Frame Descriptor
(For Ring Type
Linked List)
Frame Data #N
Frame Data Pointer #N
Memory for Frame Buffer
Status Frame Length
Next Frame Descriptor
In single linked lists, the last next frame
descriptor is filled with a Null address
Figure 7-10. Data Structure of the Receive Frame Data Buffer
7-21
ETHERNET CONTROLLER
S3C4510B
ETHERNET CONTROLLER SPECIAL REGISTERS
The special registers used by the S3C4510B ethernet controller are divided into two main groups:
— BDMA control and status registers
— MAC control and status registers
BDMA CONTROL AND STATUS REGISTERS
All registers that contain a memory address must store the address in a word-aligned format.
Table 7-2. BDMA Control and Status Registers
Registers
BDMATXCON
BDMARXCON
BDMATXPTR
BDMARXPTR
BDMARXLSZ
BDMASTAT
CAM
Offset
0x9000
R/W
R/W
R/W
R/W
R/W
R/W
R/W
W
Description
Reset Value
Buffered DMA transmit control register
Buffered DMA receive control register
Transmit frame descriptor start address
Receive frame descriptor start address
Receive frame maximum size
Buffered DMA status
0x00000000
0x00000000
0xFFFFFFFF
0xFFFFFFFF
Undefined
0x9004
0x9008
0x900C
0x9010
0x9014
0x00000000
Undefined
0x9100–0x917C
0x9200–0x92FC
CAM content (32 words)
BDMATXBUF
(1)
R/W
BDMA transmit (Tx) buffer (64 words)
for test mode addressing only
Undefined
BDMARXBUF
(1)
0x9800–0x98FC
0x9900–0x99FC
R/W
BDMA receive (Rx) buffer (64 words)
for test mode addressing only
Undefined
NOTES:
1. For testing, you can read the BDMA Tx/Rx buffer directly. The BDMA receive buffer has a 64 word by 33 bit size.
The highest bit, [32], indicates the data frame boundary, as shown in the following illustration:
32 31
0
0x9800
0x98FC
0x9900
0x99FC
EOF (End of Frame); Boundary of frame data.
Figure 7-11. End of Frame Bit
2. You can access the EOF bit by reading the address range, 0x9800-0x98FC (read into LSB bit 0).
7-22
S3C4510B
ETHERNET CONTROLLER
Buffered DMA Transmit Control Register
The buffered DMA transmit control register, BDMATXCON, is described in Tables 7-3 and 7-4 below.
Table 7-3. BDMATXCON Register
Registers
Offset
R/W
Description
Reset Value
BDMATXCON
0x9000
R/W
Buffered DMA transmit control register
0x00000000
Table 7-4. BDMA Transmit Control Register Description
Bit Number
Bit Name
Description
[4:0]
BDMA Tx burst size
(BTxBRST)
(Word size + 1) of data bursts requested in BDMA mode.
If the BTxBRST is zero, the burst size is one word.
If the BTxBRST is 31, the burst size is 32 words.
[5]
BDMA Tx stop/skip frame by
owner bit (BTxSTSKO)
This bit determines whether the BDMA Tx controller issues an
interrupt, if enabled, or skips the current frame and goes to the
next frame descriptor (assuming BDMA is not the owner).
[6]
[7]
Reserved
Not applicable.
BDMA Tx complete to send
Setting this bit enables the BDMA Tx complete to send contol
control packet interrupt enable packet interrupt when the MAC has finished sending the
(BTxCCPIE)
control packet.
[8]
[9]
BDMA Tx Null list interrupt
enable (BTxNLIE)
This bit enables the BDMA Tx Null list interrupt which indicates
that the transmit frame descriptor start address pointer,
BDMATXPTR, in the BDMA Tx block has a null (0x00000000)
address.
BDMA Tx not owner interrupt This bit enables the BDMA Tx not owner interrupt when the
enable (BTxNOIE)
ownership bit of the current frame does not belong to the
BDMA controller, and if the BTxSTSKO bit is set.
[10]
BDMA Tx buffer empty
Set this bit is "1" to enable the Tx buffer empty interrupt.
interrupt enable (BTxEmpty)
[13:11]
BDMA transmit to MAC Tx
start level (BTxMSL)
These bits determine when the new frame data in BDMA Tx
buffer can be moved to the MAC Tx FIFO when a new frame
arrives.
000 means no wait, 001 means wait to fill 1/8 of the BDMA Tx
buffer, 010 means wait to fill 2/8 of the buffer, 011 for 3/8 and
1xx for 4/8.
NOTE: If the last data of the frame arrives in BDMA Tx buffer,
the data transfer from the BDMA Tx buffer to the MAC Tx
FIFO starts immediately, regardless of the level of these bits.
7-23
ETHERNET CONTROLLER
S3C4510B
Table 7-4. BDMA Transmit Control Register Description (Continued)
Bit Number
Bit Name
Description
[14]
BDMA Tx enable (BTxEn)
When the Tx enable bit is set to "1", the BDMA Tx block is
enabled. Even if this bit is disabled, buffer data will be moved
to the MAC Tx FIFO until the BDMA Tx buffer underflows (as
long as the FIFO is not empty and the MAC Tx is enabled).
This bit is automatically disabled in the following cases: 1) if
the next frame pointer is null, or 2) if the owner bit is zero, and
the BTxSTSKO bit is set.
NOTE: The frame descriptor start address pointer must be
assigned before the BDMA Tx enable bit is set.
[15]
BDMA Tx reset (BTxRS)
Set this bit to "1" to reset the BDMA Tx block.
7-24
S3C4510B
ETHERNET CONTROLLER
BDMATxCON Register
31
16 15 14 13 12 11 10 9
8
7
6
5
4
0
B
B B B
B B
B
T
x
M
S
L
T
x
E
m
p
t
T
x
T
x
T
x
B B
T
x
T
x
T
x
T
x
C M S
C A T
N N
O L
Reserved
BTxBRST
R E
P
I
I
S
I
I
s
n
N K
E E
y
E C O
[4:0] BDMA Tx burst size (BTxBRST)
(Word size + 1) of data bursts reqested in BDMA mode. If BTxBRST is zero, the burst size is
one word. If BTxBRST is 31, the burst size is 32 words.
[5] BDMA Tx stop/skip frame by owner bit (BTxSTSKO)
0 = Skips the current frame and goes to the next frame descriptor (if BDMA is not the
owner of the frame)
1 = BDMA transmitter generates an interrupt (if enabled).
[6] Reserved
[7] BDMA Tx complete to send control packet interrupt enable (BTxCCPIE)
0 = Disable complete to send control packet interrupt.
1 = Enable complete to send control packet interrupt. (The interrupt is generated when the MAC
completes sending the control packet).
[8] BDMA Tx Null list interrupt enable (BTxNLIE)
0 = Disable transmit Null list interrupt.
1 = Enable Null list interrupt to indicate that BDMATxPTR in the BDMA Tx unit has a Null
address (0x00000000).
[9] BDMA Tx not owner interrupt enable (BTxNOIE)
0 = Disable BDMA Tx not owner interrupt for the current frame.
1 = Enable BDMA Tx not owner interrupt for the current frame (and if the BTxSTSKO bit is set).
[10] BDMA Tx buffer empty interrupt (BTxEmpty)
0 = Disable Tx buffer empty interrupt.
1 = Enable Tx buffer empty interrupt.
[13:11] BDMA transmit to MAC Tx start level (BTxMSL)
000 = No waiting
010 = Wait to fill 2/8 of the Tx buffer
100 = Wait to fill 4/8 of the Tx buffer
001 = Wait to fill 1/8 of the Tx buffer
011 = Wait to fill 3/8 of the Tx buffer
1xx = Wait to fill 4/8 of the Tx buffer
NOTE: Use this formula to calculate transmit time to the MAC Tx FIFO tBtOM:
tBtOM = (BTxMSL/8) * size of the BDMA Tx buffer
[14] BDMA Tx enable (BTxEn)
0 = Disable the BDMA transmitter.
1 = Enable the BDMA transmitter.
[15] BDMA Tx reset (BTxRS)
0 = No effect.
1 = Reset the BDMA Tx block.
Figure 7-12. Buffered DMA Transmit Control Register
7-25
ETHERNET CONTROLLER
S3C4510B
Buffered DMA Receive Control Register
The buffered DMA receive control register, BDMARXCON, is described in Tables 7-5 and 7-6 below.
Table 7-5. BDMA RXCON Register
Register
Offset Address
R/W
Description
Rest Value
BDMARXCON
0x9004
R/W
Buffered DMA receive control register
0x00000000
Table 7-6. BDMA Receive Control Register Description
Bit Number
Bit Name
Description
[4:0]
BDMA Rx burst size
(BRxBRST)
(Word size + 1) of data bursts requested in BDMA mode. If
the BRxBRST is zero, the burst size is one word. If the
BRxBRST is 31, the burst size is 32 words.
[5]
[6]
[7]
[8]
BDMA Rx stop/skip frame by This bit determines whether the BDMA Rx controller issues an
owner bit (BRxSTSKO)
interrupt, if enabled, or skips the current frame and goes to the
next frame descriptor (assuming BDMA is not the owner).
BDMA Rx memory address
inc/dec (BRxMAINC)
This bit determines whether the address is incremented or
decremented. If this bit is set to "1", the address will be
incremented.
BDMA Rx every received
frame interrupt enable
(BRxDIE)
This bit enables the BDMA Rx every received frame interrupt
which is generated by the BDMA controller each time is moves
a complete data frame into memory.
BDMA Rx Null list interrupt
enable (BRxNLIE)
This bit enables the BDMA Rx null list interrupt which indicates
that the receive frame descriptor start address pointer,
BDMARXPTR, in the BDMA Rx block has a null (0x00000000)
address.
[9]
[10]
BDMA Rx not owner interrupt This bit enables the BDMA Rx not owner interrupt when the
enable (BRxNOIE)
ownership bit of the current frame does not belong to the
BDMA controller, and if the BRxSTSKO bit is set.
BDMA Rx maximum size over This bit enables the BDMA Rx maximum size over interrupt
interrupt enable (BRxMSOIE) when the received frame size is larger than the value in
receive frame maximum size register.
[11]
BDMA Rx Big/Little Endian
(BRxLittle)
This bit determines whether the data is stored in Little- or Big-
Endian format. If it is set to "1", word swapping will take place
between the receive buffer and the system data bus.
[13:12]
BDMA Rx word alignment
(BRxWA)
The Rx word alignment bits determine how many bytes are
invalid in the first word of each data frame. These invalid bytes
are inserted when the word is assembled by the BDMA
controller. "00" = No invalid bytes, "01" = 1 invalid byte, "10" =
2 invalid bytes, and "11" = 3 invalid bytes.
7-26
S3C4510B
ETHERNET CONTROLLER
Table 7-6. BDMA Receive Control Register Description (Continued)
Bit Number
Bit Name
Description
[14]
BDMA Rx enable (BRxEn)
When the Rx enable bit is set to "1", the BDMA Rx block is
enabled. Even if this bit is disabled, the MAC will receive Rx
data until the MAC Rx FIFO overflows (as long as the FIFO is
not empty and the MAC Rx is enabled). This bit is
automatically disabled in the following cases: 1) if the next
frame pointer is Null, or 2) if the owner bit is zero, and the
BRxSTSKO bit is set.
NOTE: The frame descriptor start address pointer must be
assigned before the BDMA Rx enable bit is set.
[15]
[16]
BDMA Rx reset (BRxRS)
Set this bit to "1" to reset the BDMA Rx block.
BDMA Rx buffer empty
Set this bit is "1" to enable the Rx buffer empty interrupt.
interrupt enable (BRxEmpty)
[17]
BDMA Rx early notify
interrupt enable (BRxEarly)
Set this bit to "1" to enable the Rx early notify interrupt. The
function of this interrupt is to note the length of a data frame
that is being received from its frame length field.
7-27
ETHERNET CONTROLLER
S3C4510B
BDMARxCON Register
31
18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
0
B B
R R
B
R
x
L
i
B
R
x
B B
B R R
R x
B B
R R
B B
R R
B
R
x
W
A
x
x
x
x
x
E E
M
S
O
I
x
M S
D A T
N N
O L
Reserved
x
x
BRxBRST
a
r
l
m
p
t
t
R E
S n
I
I
S
t
I
I
E N K
C O
l
E E
E
e
y
y
[4:0] BDMA Rx burst size (BRxBRST)
Burst data size = ( BRxBRST + 1 ) word.
[5] BDMA Rx stop/skip frame (or interrupt if not owner of the current frame (BRxSTSKO)
0 = Skips the current frame and goes to the next frame descriptor.
1 = BDMA receiver generates an interrupt (if enabled).
[6] BDMA Rx memory address increment/decrement (DRxMAINC)
0 = Decrement the frame memory address.
1 = Increment the frame memory address.
[7] BDMA Rx every receuve frane interrupt enable (BRxDIE)
0 = Disable frame receive done interrupt.
1 = Enable frame receive done interrupt.
[8] BDMA Rx Null list interrupt enable (BRxNLIE)
0 = Disable Null address (0x00000000) receive interrupt.
1 = Enable Null address (0x00000000) receive interrupt.
[9] BDMA Rx not owner interrupt enable (BRxNOIE)
0 = Disable interrupt for BDMA Rx not owner of the current frame.
1 = Enable interrupt for BDMA Rx not onwer of the current frame.
[10] BDMA Rx maximum size over interrupt enable (BRxMSOIE)
0 = Disable interrupt for received frame if larger than the maximum frame size.
1 = Enable interrupt for received frame if larger than the maximum frmae size.
[11] BDMA Rx Big/Little Endian (BRxLittle)
0 = Big-Endian frame data format.
1 = Little-Endian. (Frame data in BDMA Rx buffer is word-swapped on the system bus).
[13:12] BDMA Rx word alignment (BRxWA)
00 = Do not insert an invalid byte in the first received frame data.
01 = Insert one invalid byte in the first received frame data.
10 = Insert two invalid bytes in the firat received frame data.
11 = Insert three invalid bytes in the first received frame data.
[14] BDMA Rx enable (BRxEn)
0 = Disable the BDMA receiver.
(If the MAC Rx FIFO is not empty, move data to the BDMA Rx buffer).
1 = Enable the BDMA receiver.
[15] BDMA Rx reset (BRxRs)
0 = No effect.
1 = Reset the BDMA receiver.
[16] BDMA Rx buffer empty interrupt (RxEmpty)
0 = Disable the Rx buffer empty interrupt.
1 = Enable the Rx buffer empty interrupt.
[17] BDMA Rx early notify interrupt (BRxEarly)
0 = Disable the Rx early notify interrupt.
1 = Enable the interrupt when BDMA captures the length of the received frame type.
Figure 7-13. Buffered DMA Receiver Control Register
7-28
S3C4510B
ETHERNET CONTROLLER
BDMA Transmit Frame Descriptor Start Address Register
Table 7-7. BDMATXPTR Register
R/W Description
R/W Buffered DMA transmit control register
Registers
Offset
Reset Value
0xFFFFFFFF
BDMATXPTR
0x9008
Table 7-8. BDMA Transmit Frame Descriptor Start Address Register Description
Bit Number
Bit Name
Description
[25:0]
BDMA transmit frame
descriptor start address
The BDMA transmit frame descriptor start address register
contains the address of the frame descriptor on the frame to
be sent. During a BDMA operation, this start address pointer is
updated to the next frame address.
BDMA Receive Frame Descriptor Start Address Register
Table 7-9. BDMARXPTR Register
R/W Description
R/W Buffered DMA transmit control register
Registers
Offset
Reset Value
BDMARXPTR
0x900C
0xFFFFFFFF
Table 7-10. BDMA Receive Frame Descriptor Start Address Register Description
Bit Number
Bit Name
Description
[25:0]
BDMA receive frame
descriptor start address
The BDMA receive frame descriptor start address register
contains the address of the frame descriptor on the frame to
be saved. During a BDMA operation, this start address pointer
is updated to the next frame address.
7-29
ETHERNET CONTROLLER
S3C4510B
BDMA Receive Frame Maximum Size Register
Table 7-11. BDMARXLSZ Register
R/W Description
R/W Receive frame maximum size
Registers
Offset
Reset Value
Undefined
BDMARXLSZ
0x9010
Table 7-12. BDMA Receive Frame Maximum Size Register Description
Bit Number
Bit Name
Description
[15:0]
BDMA receive frame
maximum size (BRxLSZ)
This register value controls how many bytes per frame can be
saved to memory. If the received frame size exceeds the
value stored in this location, an error condition is reported.
[31:16]
BDMA receive frame length
(BRxFSZ), read-only
When an early notification (early notify) interrupt occurs, the
frame Length/Ethernet type field contains the Frame size of
the frame that is currently being received.
To save space in the frame memory buffer, you can determine
the current frame length by 1) enabling the early notification
interrupt, and 2) reading the BRxFSZ field when the interrupt
occurs.
To calculate the value of the next frame start address pointer,
you add the current frame size value (BRxFSZ) to the BDMA
receive start address register. (For a control packet, additional
space may be needed.)
NOTE: To obtain the next Rx frame address that is to be
saved in the Rx frame start address register, we recommend
that you first halt the BDMA operation.
BDMA Status Register
Table 7-13. BDMASTAT Register
Registers
Offset
R/W
Description
Buffered DMA status
Reset Value
BDMASTAT
0x9014
R/W
0x00000000
7-30
S3C4510B
ETHERNET CONTROLLER
Table 7-14. BDMA Status Register Description
Bit Name Description
Bit Number
[0]
BDMA Rx done every
received frame (BRxRDF)
This bit is set each time the BDMA receiver moves one
received data frame to memory. This bit must be cleared for
the receiving next frame interrupt generation.
[1]
BDMA Rx null list (BRxNL)
If this bit is set, the BDMARXPTR has a null address. Even if
BDMA Rx is disabled, data is transferred from the MAC Rx
FIFO to the BDMA Rx buffer until the BDMA Rx buffer
overflows.
[2]
[3]
[4]
[5]
BDMA Rx not owner (BRxNO) If this bit is set, BDMA is not the owner of the current data
frame. The BRxSTSKO bit is set and BDMA Rx is stopped.
BDMA Rx maximum size over If this bit is set, the received frame size is larger than the value
(BRxMSO)
in the Rx frame maximum size register, BDMARXLSZ.
BDMA Rx buffer empty
(BRxEmpty)
If this bit is set, the BDMA Rx buffer is empty.
Early notification (BRxSEarly) This bit is set when the BDMA receiver has received the
length/Ether-type field of the current frame.
[6]
[7]
Reserved
Not applicable.
One more frame data in
BDMA receive buffer
(BRxFRF)
This bit is set whenever an additional data frame is received in
the BDMA receive buffer.
[15:8]
[16]
Number of frames in BDMA
receive buffer (BRxNFR)
This value indicates the total number of data frames currently
in the BDMA receive buffer.
BDMA Tx complete to send
control packet (BTxCCP)
Bit [16] is set each time the MAC sends a complete control
packet.
[17]
BDMA Tx null list (BTxNL)
If this bit is set, the BDMATXPTR value is a null address. In
this case, BDMA Tx is disabled but data continues to be
transferred from the BDMA Tx buffer to the MAC Tx FIFO until
the BDMA Tx buffer underflows. This bit is read only.
If you set BDMA Tx reset bit by software, this bit is cleared
automatically. To resume data transfer, you must then set the
new frame descriptor pointer and enable BDMA Tx.
[18]
BDMA Tx not owner (BTxNO) If [18] is set, BDMA is not owner of the current frame. In this
case, the BSTSKO bit is set and BDMA Tx is stopped.
[19]
[20]
Reserved
Not applicable.
BDMA Tx buffer empty
(BTxEmpty)
If this bit is set, the BDMA Tx buffer is empty.
[31:21]
Reserved
Not applicable.
7-31
ETHERNET CONTROLLER
S3C4510B
31
21 20 19 18 17 16 15
8
7
6
5
4
3
2
1
0
B
T
x
E
m
p
t
B
R
x
S
E
a
r
B
R
x
B
T
x
C
C
P
B
R
x
F
R
F
B
R
x
M
S
O
B
R
x
R
D
F
B
T
x
N
O
B
T
x
N
L
B
R
x
N
O
B
R
x
N
L
E
m
p
t
X
Reserved
X
BRxNFR
l
y
y
y
[0] BDMA Rx done evert received frame (BRxRDF)
0 = Reset frame data receive state.
1 = Receipt of the data frame is complete.
[1] BDMA Rx Null list (BRxNL)
0 = Reset state of new frame descriptor (BDMARXPTR) is set.
1 = Current frame descriptor address is Null (0x00000000).
[2] BDMA Rx not owner (BRxNO)
0 = BDMA is owner of the current frame.
1 = The owner of the current frame is not BDMA (CPU). In this case, BDMA Rx is
stopped and the BSTSKO bit is set.
[3] BDMA Rx maximum size over (BRxMSO)
0 = Reset state or next frame arrived at BDMA Rx buffer.
1 = Received frame exceeds the maximum frame size.
[4] BDMA Rx buffer empty (BRxEmpty)
0 = Not empty.
1 = BDMA Rx buffer empty.
[5] Early notify (BRxSEarly)
0 = Normal operation.
1 = Lengthe of current frame can be accessed by reading the BDMA receive maximum
frame size register, BDMARXLSZ [31:16].
[7] One more frame data in BDMA receive buffer (BRxFRF)
0 = Only one frame data in BDMA receive buffer.
1 = One more frame data was in the BDMA receive buffer.
[15:8] Number of frame data in BDMA receive buffer (BRxNFR)
[16] BDMA Tx complete to send control packet (BTxCCP)
0 = Clear but by writing a 1 to this bit or by resetting BDMA Tx.
1 = MAC complete to send the control packet.
[17] BDMA Tx Null list (BTxNL)
0 = Reset stste of new frame descriptor (BDMATXPTR) is set.
1 = Current frame descriptor address is Null (0x00000000).
[18] BDMA Tx not owner (BTxNO)
0 = BDMA is owner of the current frame.
1 = The owner of the current frame is not BDMA (CPU). In this case, BDMA Tx is
stopped if the BTxSTSKO bit is set to one.
[19] Reserved
[20] BDMA Tx buffer empty (BTxEmpty)
0 = Not empty
1 = BDMA Tx buffer empty.
[31:21] Reserved
NOTE:
Bit 0, 1, 2, 3, 4, 16, 17, 18 and 20 should be cleared for interrupt generation
for the next frame. The method is write 1 to the corresponding bit location.
Figure 7-14. BDMA Status Register
7-32
S3C4510B
ETHERNET CONTROLLER
Content Address Memory (CAM) Register
There are 21 CAM entries for the destination address and the pause control packet. For the destination address
CAM value, one destination address consists of 6 bytes. Using the 32-word space (32 ´ 4 bytes), you can
therefore maintain up to 21 separate destination addresses.
You use CAM entries 0, 1, and 18 to send pause control packets. To send a pause control packet, you write the
CAM0 entry with the destination address, the CAM1 entry with the source address, and the CAM 18 entry with
length/type, opcode, and operand. You then set the send pause bit in the MAC transmit control register.
Table 7-15. CAM Register
Registers
CAM
Offset
R/W
Description
Reset Value
0x9100–0x917C
W
CAM content (32 words)
Undefined
Table 7-16. Content Address Memory (CAM) Register Description
Bit Number
Bit Name
Description
[31:0]
CAM content (CAM)
The CPU uses the CAM content register as a data base for
destination address. To activate the CAM function, you must
set the appropriate enable bits in CAM enable register.
7-33
ETHERNET CONTROLLER
S3C4510B
MEDIA ACCESS CONTROL (MAC) REGISTERS
This section describes the control and status registers for the flow control 100-/10-Mbit/s ethernet MAC. These
include a master MAC control register, control registers for transmit and receive, control registers for the CAM, a
counter for network management, and various flow control registers (see Table 7-17).
Table 7-17. MAC Control and Status Registers
Registers
MACON
Offset
0XA000
0xA004
0xA008
0xA00C
0xA010
0xA014
0xA018
0xA01C
0xA028
0xA03C
0xA040
0xA044
0x9040
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Description
Reset Value
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
0x00006000
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
MAC control
CAMCON
CAM control
MACTXCON
MACTXSTAT
MACRXCON
MACRXSTAT
STADATA
STACON
Transmit control
Transmit status
Receive control
Receive status
Station management data
Station management control and address
CAM enable
CAMEN
EMISSCNT
EPZCNT
RClr/W Missed error count
R
R
R
Pause count
ERMPZCNT
ETXSTAT
Remote pause count
Transmit control frame status
NOTE: MAC transmit/receive interrupt is generated whenever the Tx/Rx status field of Tx/Rx frame descriptor is written.
7-34
S3C4510B
ETHERNET CONTROLLER
MAC Control Register
The MAC control register provides global control and status information for the MAC. The missed roll/link10 bit is
a status bit. All other bits are MAC control bits.
MAC control register settings affect both transmission and reception. You can also control transmit and receive
operations separately. To select customized operating features, you should write this register during power-up.
This way, you will not need to write or read it again during normal operation.
After a reset is complete, the MAC controller clears the reset bit. Not all PHYs support full-duplex operation.
(setting the MAC loopback bit overrides the full-duplex bit.) Also, some 10-Mb/s PHYs may interpret the loop10
bit to control different functions, and manipulate the link10 bit to indicate a different status condition.
Table 7-18. MACON Register
Registers
MACON
Offset
R/W
Description
Reset Value
0XA000
R/W
MAC control
0x00000000
Table 7-19. MAC Control Register Description
Bit Name Description
Bit Number
[0]
Halt request (HaltReq)
Set this bit to stop data packet transmission and reception as
soon as Tx/Rx of any current packets has been completed.
[1]
[2]
Halt immediate (HaltImm)
Software reset (Reset)
Set this bit to immediately stop all transmission and reception.
Set this bit to reset all MAC control and status register and
MAC state machines.
[3]
[4]
Full-duplex (FullDup)
Set this bit to start transmission while reception is in progress.
MAC loopback (MACLoop)
Set this bit to cause transmission signals to be presented as
input to the receive circuit without leaving the controller.
[5]
[6]
Reserved
MII-OFF
Not applicable
Use this bit to select the connection mode. If this bit is set to
one, 10 M bits/s interface will select the 10 M bits/s endec.
Otherwise, the MII will be selected.
[7]
Loop 10 Mb/s (Loop10)
If this bit is set, the Loop_10 external signal is asserted to the
10-Mb/s endec.
[9:8]
[10]
Reserved
Not applicable.
Missed roll (MissRoll)
This bit is automatically set when the missed error counter
rolls over.
[11]
[12]
Reserved
MDC-OFF
Not applicable.
Clear this bit to enable the MDC clock generation for power
management. If it is set to one, the MDC clock generation is
disabled.
[13]
Enable missed roll
(EnMissRoll)
Set this bit to generate an interrupt whenever the missed error
counter rolls over.
[14]
[15]
Reserved
Not applicable
Link status 10 Mb/s (Link10)
Reserved
This bit value is read as a buffered signal on the link 10 pin.
Not applicable.
[31:16]
7-35
ETHERNET CONTROLLER
CAM Control Register
S3C4510B
The three accept bits in the CAM control register are used to override CAM rejections. To place the MAC in
promiscuous mode, use CAM control register settings to accept packets with all three types of destination
addresses. The three types of destination address packets are as follows:
— Station packets, which has an even first byte. For example, 00-00-00-00-00-00.
— A multicast-group, which has an odd first byte, but which is not FF-FF-FF-FF-FF-FF. For example, 01-00-00-
00-00-00.
— A broadcast, defined as FF-FF-FF-FF-FF-FF.
When you enable CAM compare mode, the CAM memory reads the destination addresses to filter incoming
messages. (You will recall that the CAM memory consists of 6-byte entries.) An alternative way to place the MAC
in promiscuous mode is to set, in turn, to accept the them. To reject all packets, simply clear all of the bits in the
CAMCON register.
Table 7-20. CAMCON Register
Registers
CAMCON
Offset
R/W
Description
Reset Value
0XA004
R/W
CAM control
0x00000000
Table 7-21. CAM Control Register Description
Bit Name Description
Bit Number
[0]
Station accept (StationAcc)
Set this bit to accept any packet with a "unicast" station
address.
[1]
[2]
[3]
Group accept (GroupAcc)
Accept any packet with a multicast-group address.
Broadcast accept (BroadAcc) Accept any packet with a broadcast address.
Negative CAM (NegCAM)
When this bit is "0", packets the CAM recognizes are accepted
and others are rejected. When "1", packets the CAM
recognizes are rejected and others are accepted.
[4]
Compare enable (CompEn)
Reserved
Set this bit to enable compare mode.
Not applicable.
[31:5]
7-36
S3C4510B
ETHERNET CONTROLLER
MAC Transmit Control Register
To generate an interrupt after each packet, set the enable completion bit and all of the MAC error enable bits.
Using MAC transmit control register settings, you can also selectively enable interrupts for specific conditions.
Table 7-22. MACTXCON Register
Registers
Offset
R/W
Description
Transmit control
Reset Value
MACTXCON
0XA008
R/W
0x00000000
Table 7-23. MAC Transmit Control Register Description
Bit Number
Bit Name
Description
[0]
Transmit enable (TxEn)
Set this bit to enable transmission. To stop transmission
immediately, clear the transmit enable bit to "0".
[1]
Transmit halt request (TxHalt) Set this bit to halt transmission after completing any current
packet.
[2]
[3]
[4]
[5]
Suppress padding (NoPad)
Suppress CRC (NoCRC)
Fast back-off (FBack)
No defer (NoDef)
Set to not generate pad bytes for packets of less than 64 bytes.
Set to suppress addition of a CRC at the end of a packet.
Set this bit to use faster back-off times for testing.
Set to disable the defer counter. (The defer counter keeps
counting until the carrier sense (CrS) bit is turned off.)
[6]
Send Pause (SdPause)
Set this bit to send a pause command or other MAC control
packet. The send pause bit is automatically cleared when a
complete MAC control packet has been transmitted. Writing a
"0" to this register bit has no effect.
[7]
[8]
[9]
MII 10-Mb/s SQE test mode
enable (SQEn)
Set this bit to enable MII 10-Mb/s SQE test mode.
Enable underrun (EnUnder)
Set this bit to generate an interrupt if the MAC transmit FIFO is
empty during a transmission.
Enable deferral (EnDefer)
Set this bit to generate an interrupt if the MAC defers for
MAX_DEFERRAL time: "0" = 0.32768 ms at 100 Mb/s; "1" =
3.2768 ms at 10-Mb/s.
[10]
[11]
Enable no carrier (EnNCarr)
Set this bit to generate an interrupt if a carrier sense is not
detected while an entire packet is transmitted.
Enable excessive collision
(EnExColl)
Set this bit to enable an interrupt if 16 collisions occur in the
same packet.
[12]
Enable late collision
(EnLateColl)
Set this bit to generate an interrupt if a collision occurs after 512
bit times (or 64 byte times).
[13]
Enable transmit parity
(EnTxPar)
Set this bit to generate an interrupt if a parity error is detected in
the MAC transmit FIFO.
[14]
Enable completion (EnComp) Set this bit to generate an interrupt whenever the MAC
transmits or discards one packet.
[31:15]
Reserved
Not applicable.
7-37
ETHERNET CONTROLLER
S3C4510B
MAC Transmit Status Register
A transmission status flag is set in the transmit status register, MACTXSTAT, whenever the corresponding event
occurs. In addition, an interrupt is generated if the corresponding enable bit in the transmit control register is set.
A MAC transmit FIFO parity error sets TxPar, and also clears TxEn, if the interrupt is enabled.
You can read and mask the five low-order bits as a single collision count. That is, when ExColl is "1", TxColl is
"0". If TxColl is not "0", then ExColl is "0".
Table 7-24. MACTXSTAT Register
Registers
Offset
R/W
Description
Transmit status
Reset Value
MACTXSTAT
0XA00C
R/W
0x00000000
Table 7-25. MAC Transmit Status Register Description
Bit Number
Bit Name
Description
[3:0]
Transmit collision count
(TxColl)
This 4-bit value is the count of collisions that occurred while
successfully transmitting the packet.
[4]
[5]
[6]
[7]
[8]
[9]
Excessive collision (ExColl)
This bit is set if 16 collisions occur while transmitting the
same packet. In this case, packet transmission is aborted.
Transmit deferred (TxDeferred) This bit is set if transmission of a packet was deferred
because of a delay during transmission.
Paused (Paused)
This bit is set if transmission of a packet was delayed due to
a Pause being received.
This bit is set if transmission of a packet causes an interrupt
condition.
This bit is set if the MAC transmit FIFO becomes empty
during a packet transmission.
This bit is set if the MAC defers a transfer because of
MAX_DEFERRAL at 0.32768 ms for 100 Mb/s or 3.2768 ms
for 10Mb/s.
Interrupt on transmit (IntTx)
Underrun (Under)
Deferral (Defer)
[10]
[11]
No carrier (NCarr)
This bit is set if no carrier sense is detected during the
transmission a packet.
Signal quality error (SQE)
According to the IEEE802.3 rule, the SQE signal reports the
status of the PMA (MAU or transceiver) operation to the MAC
layer. After transmission is complete and 1.6 ms has elapsed,
a collision detection signal is issued for 1.5 ms to the MAC
layer. This signal is called the SQE test signal. The MAC sets
the SQE bit in the MACTXSTAT register if this signal is not
reported within the IFG time of 6.4ms.
[12]
[13]
Late collision (LateColl)
Transmit parity error (TxPar)
Completion (Comp)
This bit is set if a collision occurs after 512 bit times (or 64
byte times).
This bit is set if a collision occurs after 512 bit times (or 64
byte times).
This bit is set when the MAC transmits, or discards, one
packet.
[14]
[15]
Transmission halted (TxHalted) Transmission was halted by clearing the TxEn bit or the halt
immediate (HaltImm) bit.
[31:16]
Reserved
Not applicable.
7-38
S3C4510B
ETHERNET CONTROLLER
MAC Receive Control Register
To issue an interrupt after each packet is received, set the enable good bit and all of the error enable bits in the
MACRXCON register. You can also enable interrupts for specific conditions. Standard packet length values do
not include a preamble or a start frame delimiter (SFD).
Table 7-26. MACRXCON Register
Registers
Offset
R/W
Description
Receive control
Reset Value
MACRXCON
0XA010
R/W
0x00000000
Table 7-27. MAC Receive Control Register Description
Bit Number
Bit Name
Description
[0]
Receive enable (RxEn)
Set this bit to "1" to enable MAC receive operation. If "0", stop
reception immediately.
[1]
[2]
Receive halt request (RxHalt)
Long enable (LongEn)
Set this bit to halt reception after completing the reception of
any current packet.
Set this bit to receive frames with lengths greater than 1518
bytes.
[3]
[4]
Short enable (ShortEn)
Set this bit to receive frames with lengths less than 64 bytes.
Strip CRC value (StripCRC)
Set this bit to check the CRC, and then strip it from the
message.
[5]
[6]
Pass control packet (PassCtl)
Set this bit to enable the passing of control packets to a MAC
client.
Ignore CRC value
(IgnoreCRC)
Set this bit to disable CRC value checking.
[7]
[8]
Reserved
Not applicable.
Enable alignment (EnAlign)
Set this bit to enable the alignment interrupt. An alignment
interrupt occurs when a packet is received whose length (in bits)
is not a multiple of eight, and whose CRC is invalid.
[9]
Enable CRC error
(EnCRCErr)
Set this bit to enable the CRC interrupt. A CRC interrupt occurs
when a packet is received whose CRC is invalid or if, during its
reception, the PHY asserts Rx_er.
[10]
[11]
Enable overflow (EnOver)
Enable long error (EnLongErr)
Reserved
Set this bit to enable the overflow interrupt. An overflow
interrupt is generated when a packet is received and the MAC
receive FIFO is full.
Set this bit to enable the long error interrupt. A long error
interrupt is generated when a frame longer than 1518 bytes is
received (unless the long enable bit is set).
[12]
[13]
Not applicable.
Enable receive parity
(EnRxPar)
Set this bit to enable a receive parity interrupt if the MAC
receive FIFO detects a parity error.
[14]
Enable Good (EnGood)
Set this bit to enable the good (packet) interrupt upon error-free
reception of a complete data packet.
[31:15]
Reserved
Not applicable.
NOTE: The frame lengths given above do not include preamble and start frame delimiter (SFD).
7-39
ETHERNET CONTROLLER
S3C4510B
MAC Receive Status Register
A receive status flag is set in the MAC receive status register, MACRXSTAT, whenever the corresponding event
occurs. When a status flag is set, it remains set until another packet arrives, or until software writes a "1" to the
flag to clear the status bit. If the corresponding interrupt enable bit in the receive control register is set, an
interrupt is generated whenever a status flag is set. A MAC receive parity error sets RxPar, and also clears the
RxEn bit (if an interrupt is enabled).
Table 7-28. MACRXSTAT Register
Registers
Offset
R/W
Description
Reset Value
MACRXSTAT
0XA014
R/W
Receive status
0x00000000
Table 7-29. MAC Receive Status Register Description
Bit Name Description
Bit Number
[4:0]
[5]
Reserved
Not applicable.
Control frame received (CtlRecd) This bit is set if the packet received is a MAC control frame
(type = 8808H), if the CAM recognizes the packet address,
and if the frame length is 64 bytes.
[6]
Interrupt on receive (IntRx)
This bit is set if the reception of a packet caused an
interrupt to be generated. This includes a good received
interrupt, if the EnGood bit is set.
[7]
[8]
[9]
Receive 10-Mb/s status
(Rx10Stat)
This bit is set to "1" if a packet was received over the 7-wire
interface or to "0" if a packet was received over the MII.
Alignment error (AlignErr)
This bit is set if the frame length in bits was not a multiple of
eight and the CRC was invalid.
CRC error (CRCErr)
This bit is set if the CRC at the end of a packet did not
match the computed value, or else the PHY asserted Rx_er
during packet reception.
[10]
[11]
Overflow error (overflow)
Long error (LongErr)
This bit is set if the MAC receive FIFO was full when it
needed to store a received byte.
This bit is set if the MAC received a frame longer than 1518
bytes. (It is not set if the long enable bit in the receive
control register, MACRXCON, is set.)
[12]
[13]
Reserved
Not applicable.
Receive parity error (RxPar)
This bit is set if a parity error is detected in the MAC receive
FIFO.
[14]
[15]
Good received (Good)
This bit is set if a packet was successfully received with no
errors. If EnGood = "1", an interrupt is also generated.
Reception halted (RxHalted)
This bit is set if reception was halted by clearing RxEn or by
setting the HaltImm bit in the MAC control register,
MACON.
[31:16]
Reserved
Not applicable.
7-40
S3C4510B
ETHERNET CONTROLLER
MAC Station Management Data Register
Table 7-30. STADATA Register
Registers
STADATA
Offset
R/W
Description
Reset Value
0XA018
R/W
Station management data
0x00000000
Table 7-31. Station Management Register Description
Bit Number
Bit Name
Description
[15:0]
Station management data.
This register contains a 16-bit data value for the station
management function.
7-41
ETHERNET CONTROLLER
S3C4510B
MAC Station Management Data Control and Address Register
The MAC controller provides support for reading and writing station management data to the PHY. Setting
options in station management registers does not affect the controller. Some PHYs may not support the option to
suppress preambles after the first operation.
Table 7-32. STACON Register
Registers
STACON
Offset
R/W
Description
Reset Value
0XA01C
R/W
Station management control and address
0x00008000
Table 7-33. STACON Register Description
Bit Name Description
Bit Number
[4:0]
PHY register address (Addr)
A 5-bit address, contained in the PHY, of the register to be
read or written.
[9:5]
[10]
PHY address (PHY)
Write (Wr)
The 5-bit address of the PHY device to be read or written.
To initiate a write operation, set this bit to "1". For a read
operation, clear it to "0".
[11]
Busy bit (Busy)
To start a read or write operation, set this bit to "1". The MAC
controller clears the Busy bit automatically when the operation
is completed.
[12]
Preamble suppress (PreSup) If you set this bit, the preamble is not sent to the PHY. If it is
clear, the preamble is sent.
[15:13]
MDC clock rating
Control the MDC period.
MD_CA[15:13]
MDC period
000
001
010
16 ´ (1/fMCLK)
18 ´ (1/fMCLK)
20 ´ (1/fMCLK)
.
.
.
.
111
30 ´ (1/fMCLK)
MDC period = MD_CA[15:13] ´ 2 + 16
Default MDC_CA[15:13] = 100
[31:16]
Reserved
Not applicable.
7-42
S3C4510B
ETHERNET CONTROLLER
CAM Enable Register
The CAM enable register, CAMEN, indicates which CAM entries are valid, using a direct comparison mode. Up
to 21 entries, numbered 0 through 20, may be active, depending on the CAM size. If the CAM is smaller than 21
entries, the higher bits are ignored.
Table 7-34. CAMEN Register
Registers
CAMEN
Offset
R/W
Description
Reset Value
0XA028
R/W
CAM enable
0x00000000
Table 7-35. CAM Enable Register Description
Bit Name Description
Bit Number
[20:0]
CAM enable (CAMEn)
Set the bits in this 21-bit value to selectively enable CAM
locations 20 through 0. To disable a CAM location, clear the
appropriate bit.
[31:21]
Reserved
Not applicable.
7-43
ETHERNET CONTROLLER
S3C4510B
MAC Missed Error Count Register
The value in the missed error count register, EMISSCNT, indicates the number of packets that were discarded
due to various type of errors. Together with status information on packets transmitted and received, the missed
error count register and the two pause count registers provide the information required for station management.
Reading the missed error counter register clears the register. It is then the responsibility of software to maintain a
global count with more bits of precision.
The counter rolls over from 0x7FFF to 0x8000 and sets the corresponding bit in the MAC control register. It also
generates an interrupt if the corresponding interrupt enable bit is set. If station management software wants more
frequent interrupts, you can set the missed error count register to a value closer to the rollover value of 0x7FFF.
For example, setting a register to 0x7F00 would generate an interrupt when the count value reaches 256
occurrences.
Table 7-36. EMISSCNT Register
Registers
Offset
R/W
Description
Reset Value
EMISSCNT
0XA03C
R(Clr)/W Missed error count
0x00000000
Table 7-37. Missed Error Count Register Description
Bit Number
Bit Name
Description
[15:0]
Alignment error count
(AlignErrCnt)
The number of packets received with alignment errors. This
software counter increments at the end of a packet reception if
the Rx_Stat value indicates an alignment error.
CRC error count (CRCErrCnt) The number of packets received with a CRC error. This
software counter increments if the Rx_Stat value indicates a
CRC error. If the Rx_Stat value indicates another type of error,
such as an alignment error, this counter is not incremented.
Missed error count
(MissErrCnt)
The number of valid packets rejected by the MAC unit
because of MAC receive FIFO overflows, parity errors, or
because the Rx_En bit was cleared. This count does not
include the number of packets rejected by the CAM.
[31:16]
Reserved
Not applicable.
7-44
S3C4510B
ETHERNET CONTROLLER
MAC Received Pause Count Register
The received pause count register, EPZCNT, stores the current value of the 16-bit received pause counter.
Table 7-38. EPZCNT Register
Registers
EPZCNT
Offset
R/W
Description
Reset Value
0XA040
R
Pause count
0x00000000
Table 7-39. Received Pause Count Register Description
Bit Number
Bit Name
Description
[15:0]
Received pause count
(EPZCNT)
The count value indicates the number of time slots the
transmitter was paused due to the receipt of control pause
operation packets from the MAC.
MAC Remote Pause Count Register
The remote Pause count register, ERMPZCNT, stores the current value of the 16-bit remote Puase counter.
Table 7-40. ERMPZCNT Register
Registers
Offset
R/W
Description
Remote pause count
Reset Value
ERMPZCNT
0XA044
R
0x00000000
Table 7-41. Remote Pause Count Register Description
Bit Number
Bit Name
Description
[15:0]
Received pause count
(EPZCNT)
The count value indicates the number of time slots that a
remote MAC was paused as a result of its sending control
pause operation packets.
7-45
ETHERNET CONTROLLER
S3C4510B
MAC Transmit Control Frame Status
The transmit control frame status register, ETXSTAT, is a RAM-based register which provides the status of a
MAC control packet as it is sent to a remote station. This operation is controlled by the SdPause bit in the
transmit control register, MACTXCON.
It is the responsibility of the DMA engine to read this register, and to generate an interrupt to notify the system
that the transmission of a MAC control packet has been completed.
Table 7-42. ETXSTAT Register
Registers
ETXSTAT
Offset
R/W
Description
Reset Value
0X9040
R
Transmit control frame status
0x00000000
Table 7-43. Transmit Control Frame Register Description
Bit Name Description
Tx_Stat value
Bit Number
[15:0]
A 16-bit value indicating the status of a MAC control packet as
it is sent to a remote station. Read by the DMA engine.
7-46
S3C4510B
ETHERNET CONTROLLER
ETHERNET CONTROLLER OPERATIONS
This section contains additional details about the following operations of the S3C4510B ethernet controller:
— MAC frame and packet formats
— Transmitting a frame
— Receiving a frame
— Full-duplex pause operation
— Error signalling and network management
MAC Frame and Packet Formats
The MAC transmits each byte of all fields, except the FCS, least-significant bit first. In this document, the term
"packet" is used to denote all of the bytes that are transmitted and received, while "frame" refers only to the bytes
delivered by the station for transmission, and to the station who is receiving.
Table 7-44 lists the eight fields in a standard data packet (IEEE 802.3/Ethernet frame). See also Figure 7-13.
Table 7-44. MAC Frame and Package Format Description
Field Name
Preamble
Field Size
Description
7 bytes
The bits in each preamble byte are 10101010, transmitted from left
to right.
Start frame delimiter
(SFD)
1 byte
6 bytes
6 bytes
The SFD bits are 10101011, transmitted from left to right.
Destination address
The destination address can be an individual address or a multicast
(or broadcast) address.
Source address
The MAC does not interpret the source address bytes. However, to
qualify as a valid station address, the first bit transmitted (the LSB
of the first byte) must be a "0".
Length or type
2 bytes
The MAC treats length fields greater than 1500 bytes as type fields.
Byte values less than or equal to 1500 indicate the number of
logical link control (LLC) data bytes in the data field. The MAC
transmits the high-order byte first.
Logical link control
(LLC) data
46 to 1500 bytes Data bytes used for logical link control.
PAD
0 to 46 bytes
4 bytes
If the LLC data is less than 46 bytes long, the MAC transmits pad
bytes of all zeros.
Frame check
sequence (FCS)
The FCS field contains a 16-bit error detection code that is
computed as a function of all fields except the preamble, the SFD,
and the FCS itself. The FCS - 32 polynomial function is as follows: "
X32 + X26 + X23 + X16 + X12 + X11 + X10 + X8 + X7 + X5 + X4 +
X2 + X1 + 1".
7-47
ETHERNET CONTROLLER
S3C4510B
Packet (Encoded on the Medium)
Data Frame (sent by user)
Added by transmitter
Added by
Transmitter,
Stripped by
Receiver
Data frame (delivered to user)
Optionaly stripped
by receiver
S
F
D
Destination
Address
Source
Address
Length or
type
Preamble
7 bit
LLC data
PAD
0-46
FCS
46-1500
bytes
1
6 bytes
6 bytes
2 bytes
4 bytes
LLC header
LLC information field
IP/X.25/......
DSAP SSAP CTRL
OR
SNAP
OUI PID
DSAP SSAP CTRL
IP/X.25/......
1 byte 1 byte 1 byte 3 bytes 2 bytes
DSAP = Destination service access point
CTRL = Control field
OUI = Origanizationally unique identifier
SFD = Starting frame delimiter
SSAP = Source service access point
SNAP = Subnetwork access protocol
PID = Protocol identifier
LLC = Logical lick control
FCS = Frame check sequence
Figure 7-15. Fields of an IEEE802.3/Ethernet Packet (Frame)
Options That Affect the Standard MAC Frame
There are a number of factors and options which can affect the standard MAC frame, as described in Table 7-44:
— Some PHYs may deliver a longer or shorter preamble.
— Short packet mode permits LLC data fields with less than 46 bytes. Options are available to suppress
padding and to support the reception of short packets.
— Long packet mode supports LLC data fields with more than 1500 bytes. An option is also available to support
to reception of long packets.
— "No CRC" mode suppresses the appending of a CRC field.
— "Ignore CRC" mode allows the reception of packets without valid CRC fields.
7-48
S3C4510B
ETHERNET CONTROLLER
Destination Address Format
Bit 0 of the destination address is an address type designation bit. It identifies the address as either an individual
or a group address. Group addresses are sometimes called "multicast" addresses and individual addresses are
called "unicast" addresses. The broadcast address is a special group address in the special hex format: FF-FF-
FF-FF-FF-FF.
Bit 1 of the destination address distinguishes between locally or globally administered addresses. For globally
administered or universal (U) addresses, the bit value is "0". If an address is to be assigned locally, you must set
this bit to "1". For the broadcast address, this bit must also be set to "1".
Destination Address
MAC Address (3 bytes)
Block ID or OUI (3 bytes)
U/L
I/G
[0] Individual or group flag (I/G)
0 = Individual (= unicast) address.
1 = Group (= multicast) address.
[1] Universal or local address flag (U/L)
0 = Universal address.
1 = Local address.
Figure 7-16. Destination Address Format
Special Flow Control Destination Address
The current specification for full-duplex flow control specifies a special destination address for the Pause
operation packet. In order for the MAC to receive packets which contain this special destination address, the
address must be programmed in one of the CAM entries. This CAM entry must then be enabled, and the CAM
activated.
Some CAM entries are also used when generating a flow control packet using the SdPause bit in the MAC
transmit control register.
7-49
ETHERNET CONTROLLER
S3C4510B
TRANSMITTING A FRAME
To transmit a frame, the transmit enable bit in the transmit control register must be set and the transmit halt
request bit must be zero. In addition, the halt immediate and halt request bits in the MAC control register must be
"0". These conditions are normally set after any BDMA controller initialization has occurred. The system then
uses the Tx_wr# and Tx_EOF signals to transfer bytes to the transmit data buffer.
The transmit state machine starts transmitting the data in the FIFO, and will retain the first 64 bytes until after
this station has acquired the net. At that time, the transmit block requests more data and transmits it until the
system asserts the Tx_EOF input, signaling the end of data to be transmitted. The transmit block appends the
calculated CRC to the end of the packet, and transmission ends. It then sets the transmit status register bit 0,
signaling a successful transmission. This action may causes an interrupt, if enabled.
A frame transmit operation can be subdivided into two operations, 1) a MII interface operation, and 2) a BDMA/
MAC interface operation.
BDI TRANSMIT OPERATION
The BDI transmit operation is a simple FIFO mechanism. The BDMA engine stores data to be transmitted, and
the transmit state machine empties it when the MAC successfully acquires the net.
Note that the two time domains intersect at the FIFO controller. The writing and reading of data is asynchronous
and on different clocks. Reading is driven by either a 25-MHz or a 2.5-MHz transmit clock. Writing is driven by
the synchronous Sys_clk, which is asynchronous to Tx_clk.
After a reset, the transmit FIFO is empty. The transmit block asserts the Tx_rdy signal, and transmission is
disabled. To enable transmission, the system must set the transmit enable bit in the transmit control register. In
addition, eight bytes of data must be present in the transmit FIFO. The BDMA engine can start stuffing data into
the FIFO, and then enable the transmit bit. (Or it can enable the transmit bit first and then start stuffing data into
the FIFO.) The transmit operation can only start if both of these conditions are met.
7-50
S3C4510B
ETHERNET CONTROLLER
BDI Transmit Timing
When the transmit block asserts the Tx_rdy signal, the BDMA engine can write data into the transmit FIFO by
asserting the Tx_wr# signal. Figure 7-15 shows timing sequences for back-to-back transfers and transfers with
wait states. This is a synchronous interface, which means that data is latched in at the rising edge of the Sys_clk
when Tx_wr# is asserted. For slower interfaces, the rising edge of Tx_wr# can be delayed.
This is the equivalent of asserting a wait state in a synchronous operation. The transmit FIFO machine checks
the Tx_par and the Tx_EOF bits. If there is a parity error, the transmit block aborts the transmission, resets the
FIFO, and generates an interrupt by setting the TxPar bit in the transmit status register.
The Tx_EOF bit signals the end of one frame to be transmitted. When it detects this bit, the transmit block de-
asserts Tx_rdy until it has transmitted the packet. It then re-asserts Tx_rdy when the BDMA can transfer the next
packet into the MAC FIFO.
SYS_CLK
Rx_rdy
Rx_wr#
B1
B1
B1
B2
B2
B2
B3
B3
B3
Rx_DB
Rx_BE#
Rx_par
Rx_EOF
Figure 7-17. BDI Transmit Data Timing
7-51
ETHERNET CONTROLLER
S3C4510B
MII TRANSMIT OPERATION
The transmit block consists of three state machines: the gap_ok state machine, the back_off state machine, and
the main transmit state machine.
The gap_ok State Machine
The gap_ok state machine tracks and counts the inter-gap timing between the frames. When not operating in
full-duplex mode, it counts 96 bit times from the deassertion of the carrier sense (CrS) signal. If there is any
traffic within the first 64 bit times, the gap_ok state machine reset itself and starts counting from zero.
If there is any traffic in the last 1/3 of the inter-frame gap, the gap_ok state machine continues counting.
Following a successful transmission, a gap_ok is sent at the end of the next 96 bit times, regardless of the
network traffic.
In full-duplex mode, the gap_ok state machine starts counting at the end of the transmission and the gap_ok
signal is sent at the end of the 96 bit times, regardless of the network traffic.
Assemble MAC frame
Yes
Carrier sense==ON?
Wait for interframe gap
(96-bit time), start Tx
with preamble + SFD
Continue
transmission
Yes
Collision detected?
Preamble and SFD
transmitted?
Done. Complete Tx
Yes
Stop transmission,
send 32-bit jam,
++ Attemp_count
Wait for back-off time:
(=slot time x r),
Attempt_count>=
Max_attempt?
k = minimum (n, back-off limit (=10))
0<=n <Max_attempt (=16)
0<= random integer (r) <= 2k
Yes
Report attempt limit
exceeded error
; To upper level layer
Figure 7-18. CSMA/CD Transmit Operation
7-52
S3C4510B
ETHERNET CONTROLLER
The back_off State Machine
The back_off state machine implements the back-off and retry algorithm of the 802.3 CSMA/CD. When a
collision is detected, the main transmit state machine starts the back_off state machine¢s counters and waits for
the back-off time (including zero) to elapse. This time is a multiple of 512 bit times that elapse before the packet
that caused the collision is re-transmitted.
Each time there is a collision (for one single packet), the back_off state machine increments an internal retry
attempt countner. A 11-bit pseudo random number generator outputs a random number by selecting a subset of
the value of the generator at any time. The subset is incremented by one bit for each subsequent attempt. This
implementation is represented by the following equation:
0 =< random integer(r) < 2K
K = min (n, backoff limit (= 10))
where "r" is the number of slot times the MAC must wait in case of a collision, and "n" is the number of retry
attempts.
For example, after the first collision, "n" is 1 and "r" is a random number between 0 and 1. The pseudo random
generator in this case is one-bit wide and gives a random number of either 0 or 1. After the second attempt, "r" is
a random number between 0 and 3. Therefore, the state machine looks at the two least-significant bits of the
random generator (n = 2), which gives a value between 0 and 3.
The Main Transmit State Machine
The main transmit state machine implements the remaining MAC layer protocols. If there is data to be
transferred, if the inter-frame gap is valid, and if the MII is ready (that is, if there are no collisions and no CRS in
full-duplex mode), the transmit block then transmits the preamble followed by the SFD.
After the SFD and preamble are transmitted, the block transmits 64 bytes of the data, regardless of the packet
length, unless short transmission is enabled. This means that if the packet is less than 64 bytes, it will pad the
LLC data field with zeros. It will also appends the CRC to the end of the packet, if CRC generation is enabled.
If there is any collision during this first 72 bytes (8 bytes of preamble and SFD, and 64 bytes of the frame), the
main transmit state machine stops the transmission and transmits a jam pattern (32 bits of 1¢s). It then
increments the collision attempt counter, returns control to the back_off state machine, and re-transmits the
packet when the back-off time has elapsed and the gap time is valid.
If there are no collisions, the transmit block transmits the rest of the packet. At this time (that is, after the first 60
bytes have been transmitted without collisions), the main transmit state machine lets the BDMA engine overwrite
the packet. After it transmits the first 64 bytes, the transmit block transmits the rest of the packet, appending the
CRC to the end. parity errors, FIFO errors, or more than 16 collisions will cause the transmit state machine to
abort the packet (no retry) and queue up the next packet.
In case of any transmission errors, the transmit block sets the appropriate error bit in the transmit status register.
It may also generate an interrupt, depending on the enable bit settings in the transmit control register.
7-53
ETHERNET CONTROLLER
S3C4510B
Tx_clk
Tx_en
P
R
E
A
M
B
L
E
TxD [3:0]
Crs
Col
Figure 7-19. Timing for Transmit without Collision
Tx_clk
Tx_en
P1 P2 P3 P4 P5 P6 P7 P8 J1 J2 J3
J4
TxD [3:0]
Crs
Col
Figure 7-20. Timing for Transmit with Collision in Preamble
7-54
S3C4510B
ETHERNET CONTROLLER
RECEIVING A FRAME
The receive block, when enabled, constantly monitors a data stream coming either from the MII or, if in loop-
back mode, from the transmit block. The MII supplies from zero to seven bytes of preamble, followed by the start
frame delimiter (SFD). The receive block checks that the first nibbles received are preamble, and then looks for
the SFD (10101011) in the first eight bytes. If it does not detect the SFD by then, it treats the packet as a
fragment and discards it.
The first nibble of destination address follows the SFD, least-significant bits first. When it has received a byte,
the receive block generates parity, stores the byte with its parity in the receive FIFO, and asserts Rx_rdy. It
combines subsequent nibbles into bytes and stores them in the FIFO.
BDI RECEIVE DATA TIMING
When the system asserts Rx_rd#, the receive block reads the first byte from the FIFO, checks parity, and drives
the byte on Rx_DB, and the byte's parity on Rx_par. If the FIFO is now empty, it drops Rx_rdy. When it drives
out the last byte of a packet, it asserts Rx_EOF.
Figure 7-19 shows the timing sequence for transmitting bytes back-to-back, transmitting with wait states, and
transmitting the last byte.
Sys_clk
Rx_rdy
Rx_rd#
B1
B2
B3
BN
Rx_DB
Rx_par
PAR
PAR
PAR
PAR
Rx_EOF
Figure 7-21. BDI Receive Data Timing
7-55
ETHERNET CONTROLLER
S3C4510B
RECEIVE FRAME TIMING WITH/WITHOUT ERROR
If, during frame reception, both Rx_DV and Rx_er are asserted, a CRC error is reported for the current packet.
As each nibble of the destination address is received, the CAM block attempts to recognize it. After receiving the
last destination address nibble, if the CAM block rejects the packet, the receive block asserts the Rx_toss signal,
and discards any bytes not yet removed from the receive FIFO that came from the current packet. If this
operation leaves the FIFO empty, it drops Rx_rdy.
Figure 7-20 shows the MII receive data timing without error. The RX_DV signal, which entered the MII from the
PCS layer, will be ON when the PCS layer recovers the Rx_clk from the receive bit stream and delivers the
nibble data on RxD[3:0] data line. The RX_DV signal must be ON before the starting frame delimiter(SFD) is
received. When the Rx_DV signal is ON, the preamble and SFD parts of the frame header are delivered to MII,
synchronized with the 25-MHz Rx_clk. (The carrier sense (CrS) signal was turned on during receive frame.)
As its response to the Rx_er signal, the MII immediately inserts an alternative data bit stream into the receive
data stream. As a result, the MAC discards this received error frame using the FCS.
Rx_clk
Rx_DV
Preamble
SFD
DA
SFD
RxD [3:0]
Crs
Rx_er
Figure 7-22. Receiving Frame without Error
Rx_clk
Rx_DV
Preamble
SFD
DA
SFD
RxD [3:0]
Crs
Rx_er
Figure 7-23. Receiving Frame with Error
7-56
S3C4510B
ETHERNET CONTROLLER
Carrier Sense== On
yse
Carrier sense = On,
after detection SFD,
store byte-stream in in FISO
no
Discard the Frame
Report Error Status
Recognize Address?
Move the byte stream in
the FIFO to the receive
buffer memory
Frame too short ?
Frame too long?
Valid FCS ?
Interrput CPU for
Handing the Frame
Check ethertype or length field
Disassemble Frame
MAC Drive Software
(Software jobs for typical LAN cards)
Signal to Upper Layer
Figure 7-24. CSMA/CD Receive Operation
7-57
ETHERNET CONTROLLER
S3C4510B
THE MII STATION MANAGER
The MDIO (management data input/output) signal line is the transmit and receive path for control/status
information for the station management entity, STA. The STA controls and reads the current operating status of
the PHY layer. The speed of transmit and receive operations is determined by the management data clock,
MDC.
The frame structure of the STA which writes command to control registers, or which reads the status register of a
PHY device, is shown Table 7-45. The PHY address is defined as the identification (ID) value of the various PHY
devices that may be concected to a single MAC. Register addresses can contain the ID value for up to 32 types
of PHY registers.
Turn-around bits are used to regulate the turn-around time of the transmit/receive direction between the STA and
a PHY device. So that the STA can read the set value of a PHY device register, it must transmit the frame data,
up to a specific register address, to the PHY device. During the write time (which is an undirected transmission),
the STA transmits a stream of turn-around bits. As a result, by transmitting a write or read message to a PHY
device through the MDIO, the STA can issue a request to set the operation or to read the operation status.
As its response this message, the PHY device resets itself, sets loop-back mode, selects active/non-active auto-
negotiation process, separates the PHY and MII electrically, and determines whether or not to activate the
collision detection process.
When it receives a read command, the PHY reports the kind of PHY device it is, such as 100Base-T4, FDX
100base-X, HDX 100Base-X, 10-Mb/s FDX, or 10-Mb/s HDX.
Table 7-45. STA Frame Structure Description
Preamble Start of Operation
PHY
Register Turnaround
Data
Idle
Frame
Code
Address Address
Write
(Command)
11111111
(32 bits)
01
01 (write)
5 bits
5 bits
5 bits
5 bits
10 (2 bits) 16 bits
(register
Z
value)
Read (Status) 11111111
(32 bits)
01
10 (read)
Z0
16 bits
(register
value)
Z
Direction: STA to PHY
Direction: PHY to STA
7-58
S3C4510B
ETHERNET CONTROLLER
FULL-DUPLEX PAUSE OPERATIONS
Transmit Pause Operation
To enable a full-duplex Pause operation, the special broadcast address for MAC control packets must be
programmed into the CAM, and the corresponding CAM enable bit set. The special broadcast address can be a
CAM location. To optimize the utilization CAM entries, you can specify a preference for specific CAM locations.
This feature is described below.
The MAC receive circuit recognizes a full-duplex Pause operation when the following conditions are met:
— The type/length field has the special value for MAC Control packets, 0x8808.
— The packet is recognized by the CAM.
— The length of the packet is 64 bytes.
— The operation field specifies a Pause operation.
When a full-duplex pause operation is recognized, the MAC receive circuit loads the operand value into the
pause count register. It then signals both the MAC and the BDMA engine that the pause should begin at the end
of the current packet, if any.
The pause circuit maintains the pause counter, and decrements it to zero. It does this before it signals the end of
the pause operation, and before allowing the transmit circuit to resume its operation.
If a second full-duplex pause operation is recognized while the first operation is in effect, the pause counter is
reset with the current operand value. Note that a count value of zero may cause pre-mature termination of a
pause operation that is already in progress.
Remote Pause Operation
To send a remote pause operation, following these steps:
1. Program CAM location 0 with the destination address.
2. Program CAM location 1 with the source address.
3. Program CAM location 18 with length/type field, opcode, and operand.
4. Program the 2 bytes that follow the operand with 0000H.
5. Program the three double words that follow CAM location 18 with zeros.
6. Write the transmit control register to set the SdPause bit.
The destination address and source address are commonly used as the special broadcast address for MAC
control frames and the local station address, respectively. To support future uses of MAC control frames, these
values are fully programmable in the flow control 100-/10-Mbit/s Ethernet MAC.
When the remote Pause operation is completion, the transmit status is written to the transmit control frame status
register. The BDMA engine is responsible for providing an interrupt enable control.
7-59
ETHERNET CONTROLLER
Error Signalling
S3C4510B
The error/abnormal operation flags asserted by the MAC are arranged into transmit and receive groups. These
flag groups are located either in the transmit status register (Tx_stat) or the receive status register (Rx_stat). A
missed packet error counter is included for system network management purposes.
Normally, software does not have enough direct control to examine the status registers directly. Therefore, the
BDMA engine must store the values in system memory so that they can be examined there by software.
Reporting of Transmission Errors
A transmit operation terminates when the entire packet (preamble, SFD, data, and CRC) has been successfully
transmitted through the MII without a collision. In addition, the transmit block detects and reports both internal
and network errors.
Under the following conditions, the transmit operation will be aborted (in most cases).
Parity error
The 8 bits of data coming in through the BDII has an optional parity bit. A
parity bit also protects each byte in the MAC transmit FIFO. If a parity error
occurs, it is reported to the transmit state machine, and the transmission is
aborted. A detected parity error sets the TxPar bit in the transmit status register.
Transmit FIFO underrun
No CRS
The 80-byte transmit FIFO can handle a system latency of 6.4bi (640 bit times).
An underrun of the transmit FIFO during transmission indicates a system
problem (namely, that the system cannot keep up with the demands of the
MAC), and the transmission is aborted.
The carrier sense signal (CrS) is monitored from the beginning of the start of
frame delimiter (SFD) to the last byte transmitted. A "No CrS" indicates that CrS
was never present during transmission (a possible network problem), but the
ransmission will NOT be aborted. Note that during loop-back mode, the MAC is
disconnected from the network, and a "No CRC" will not be detected.
Excessive collision error
Late collision error
Whenever the MAC encounters a collision during transmit, it will back off,
update the "attempt counter," and retry the transmission later on. When the
attempt counter reaches 16 (16 attempts that all resulted in a collision), the
transmission is aborted. This indicates a network problem.
(Transmit out of window collision)
Normally, the MAC would detect a collision (if one occurs) within the first 64
bytes of data that are transmitted, including the preamble and SFD. If a collision
occurs after this time frame, a possible network problem is indicated. The error
is reported to the transmit state machine, but the transmission is NOT aborted.
Instead, it performs a back-off, as usual.
Excessive deferral error
During its first attempt to send a packet, the MAC may have to defer the
transmission because the network is busy. If this deferral time is longer than 32K
bit times, the transmission is aborted. Excessive deferral errors indicate a
possible network problem.
7-60
S3C4510B
ETHERNET CONTROLLER
Reporting of Receive Errors
When it detects a start of frame delimiter (SFD), the receive state machine starts putting data it has received
from the MII into the receive FIFO. It also checks for internal errors (FIFO overruns) while reception is in
progress.
When the receive operation is completed, the receive state machine checks for external errors, such as frame
alignment, length, CRC, and frame too long.
The following is a description of the types of errors that may occur during a receive operation:
Priority error
A parity bit protects each byte in the MAC receive FIFO. If a parity error occurs,
it is reported to the receive state machine. A detected parity error sets the RxPar
bit in the receive status register.
Frame Alignment Error
(Dribble)
After receiving a packet, the receive block checks that the incoming packet
(including CRC) was correctly framed on an 8-bit boundary. If it is not and if the
CRC is invalid, data has been disrupted through the network, and the receive
block reports a frame alignment error. A CRC error is also reported.
CRC Error
After receiving a packet, the receive block checks the CRC for validity, and
reports a CRC error if it is invalid. The receive unit can detect network-related
errors such as CRC, frame alignment, and length errors. It can also detect these
types of errors in the following combinations:
—
—
—
—
CRC errors only
Frame alignment and CRC errors only
Length and CRC errors only
Frame alignment, length, and CRC errors
Frame too long
Receive FIFO overrun
MII error
The receive block checks the length of the incoming packet at the end of
reception (including CRC, but excluding preamble and SFD). If the length is
longer than the maximum frame size of 1518 bytes, the receive block reports
receiving a "long packet", unless long frame mode is enabled.
During reception, the incoming data are put into the receive FIFO temporarily
before they are transferred to the system memory. If the FIFO is filled up
because of excessive system latency or for other reasons, the receive block sets
the overrun bit in the receive status register.
The PHY informs the MAC if it detects a medium error (such as a coding
violation) by asserting the input pin Rx_er. When the MAC sees Rx_er asserted,
it sets CRCErr bit of the receive status register.
7-61
ETHERNET CONTROLLER
S3C4510B
Timing Parameters for MII Transactions
The timing diagrams in this section conform to the guidelines described in the "Draft Supplement to ANSI/IEEE
Std. 802.3, Section 22.3, Signal Characteristics."
Tx_clk
0ns MIN, 25ns MAX
TxD[3:0]
Tx_en
Figure 7-25. Transmit Signal Timing Relationship at MII
Rx_clk
10ns MIN 10ns MIN
RxD[3:0],
Rx_DV,
Rx_er
INPUT VALID
Figure 7-26. Receive Signal Timing Relationship at MII
7 Cycles
7 Cycles
MDC
0ns MIN, 300ns MAX
MDIO
Figure 7-27. MDIO Sourced by PHY
MDC
10ns MIN 10ns MIN
MDIO
INPUT VALID
Figure 7-28. MDIO Sourced by STA
7-62
S3C4510B
ETHERNET CONTROLLER
MAC CONTROLLER 7–WIRE INTERFACE TIMING
Table 7-46. 7-Wire Interface Receive Timing
Symbol
Ts_crs
Th_crs
Ts_dv
Th_dv
Ts_d
Condition
CRS low to high setup time
CRS low to high hold time
RX_DV set-up time
RX_DV hold time
Min
0.92
0.38
0.9
Typ
Max
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
0.4
RxD set-up time
0.79
0.51
0.9
Th_d
RxD hold time
Ts_er
Th_er
Tcyc
Rx_er set-up time
Rx_er hold time
0.4
Rx_clk clock period
100
Th_crs
Th_dv Ts_dv
Tcyc
Rx_clk
Rx_DV
RxD
Ts_crs
Preamble
SFD
DA
CRC
Crs
Th_d Ts_d
Rx_er
Th_er Ts_er
Figure 7-28. Rx Timing in 7 Wire Interface
7-63
ETHERNET CONTROLLER
S3C4510B
Table 7-47. 7-Wire Interface Transmit Timing
Symbol
Condition
Tx_en set-up time
Tx_en hold time
Min
0.8
Typ
Max
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
Ts_en
Th_en
Ts_crs
Th_crs
Ts_d
0.71
0.72
0.75
1.2
CRS set-up time
CRS hold time
TxD set-up time
TxD hold time
Th_d
0.5
Ts_col
Th_col
Tcol
COL set-up time
COL hold time
0.82
0.79
200
COL minimum active time
Ts_col
Th_col
Th_cn Ts_en
Tx_clk
Tx_en
TxD
Th_d
Ts_d
Crs
Ts_crs
Th_crs
Col
Tcol
Figure 7-29. Tx Timing in 7 Wire Interface
7-64
S3C4510B
HDLC CONTROLLERS
8
HDLC CONTROLLERS
OVERVIEW
The S3C45310B has two high-level data link controllers (HDLCs) to support two-channel serial communications.
The HDLC module supports a CPU/data link interface that conforms to the synchronous data link control (SDLC)
and high-level data link control (HDLC) standards. In addition, the following function blocks are integrated into the
HDLC module:
— Two-channel DMA engine for Tx/Rx
— Support buffer descriptors per frame
— Digital phase-locked loop (DPLL) block
— Baud rate generator (BRG)
8-1
HDLC CONTROLLERS
S3C4510B
FEATURES
Important features of the S3C4510B HDLC block are as follows:
— Protocol features:
Flag detection and synchronization
Zero insertion and deletion
Idle detection and transmission
FCS encoding and detection (16-bit)
Abort detection and transmission
— Four address station registers and one mask register for address search mode
— Selectable CRC/No-CRC mode
— Automatic CRC generator preset
— Digital PLL block for clock recovery
— Baud rate generator
— NRZ/NRZI/FM/Manchester data formats for Tx/Rx
— Loop-back and auto-echo mode
— Tx and Rx clock inversion
— Tx and Rx FIFOs with 8-word (8 x 32-bit) depth
— Selectable 1-word or 4-word data transfer mode for Tx/Rx
— Data alignment logic
— Endian translation
— Programmable interrupts
— Modem interface
— Hardware flow control
— Buffer descriptor for Tx / Rx
— Two-channel DMA Controller
Two channels for HTxFIFO and HRXFIFO
Single or 4-word (4 x 32-bit) burst transfer mode
Maximum frame size allows for up to 64K bytes
— Up to 10 Mbps full-duplex operation using an external/internal clock
— HDLC frame length based on octets
8-2
S3C4510B
HDLC CONTROLLERS
FUNCTION DESCRIPTIONS
Figure 8-1 shows the HDLC module's function blocks. These function blocks are described in detail in the
following sections.
Tx FIFO
(8 Words)
FCS Generator
autoecho
Address
DMA
Controlller
Zero
Insertion
Flag/Abort/Idle
Generateor and
Transmitter
Encoder
TxD
HDLC Control
and Status
Registers
Flag/Abort/Idle
Detection
Word
Zero
Deletion
FCS Checker
Control
Data
loop
Bus Arbiter/
Controller
Receive shift
Register
Decoder
RxD
TxC
Address
dplloutR
dplloutT
Rx FIFO
(8 words)
DPLL
RxC
brgout1
BRG
brgout2
MCLK2
(= 25 MHz)
Figure 8-1. HDLC Module Block Diagram
8-3
HDLC CONTROLLERS
S3C4510B
HDLC FRAME FORMAT
The HDLC transmits and receives data (address, control, information and CRC field) in a standard format called
a frame. All frames start with an opening flag (beginning of flag, BOF, 7EH) and end with a closing flag (end of
flag, EOF, 7EH). Between the opening and the closing flags, a frame contains an address (A) field, a control (C)
field, an information (I) field (optional), and a frame check sequence (FCS) field (see Table 8-1).
Table 8-1. HDLC Data Frame Format
Opening
Flag
Address
Field
Control
Field
Information
Field
Frame Check
Sequence Field
Closing
Flag
01111110
8 bits per byte
8 bits per byte
8 bits per byte;
variable length
16 bits
01111110
NOTE: The address field can be extended up to four bytes using a optional software control setting.
Flag (F)
A flag is a unique binary pattern (01111110) that is used to delimit HDLC frames. This pattern is generated
internally by the transmitter. An opening flag starts a frame and a closing flag ends the frame. Opening flags and
closing flags are automatically appended to frames.
A single flag pattern can optionally serve as both the closing flag of one frame and the opening flag of the next
one. This feature is controlled by the double-flag (FF), single-flag (F), or frame separator selection bit (the
TxSDFL bit in the HCON register).
Order of Bit Transmission
Address field, control field, and information field bytes are transferred between the CPU and the HDLC module in
parallel over the data bus. These bytes are transmitted and received LSB first. The 16-bit frame check sequence
(FCS) field is, however, transmitted and received MSB first.
8-4
S3C4510B
HDLC CONTROLLERS
Address (A) Field
The eight bits that follow the opening flag are called address (A) field. The address field are expendable. To
extend this address byte, simply user-defined address write to the station address register. To check address byte
against the incoming data, have to be used the MASK register. If match occurred, the frame's data including
address and CRC(16-bit) into the HRXFIFO and then moved to system memory. If it is not matched, simply
discarded. S3C4510B allows up to 32-bits address. For instance, SDLC and LAPB use an 8-bit address. LAPD
further divides its 16-bit address into different fields to specify various access points one piece of equipment.
Some HDLC-type protocol allows for extended addressing beyond 16-bit.
Control (C) Field
The eight bits that follow the address field are called the control (link control, C) field. The S3C4510B HDLC
module treats the control field in the same way as the information field. That is, it passes the eight bits to the
CPU or memory during reception. The CPU is responsible for how the control field is handled and what happens
to it.
Information (I) Field
The information (I) field follows the control (C) field and precedes the frame check sequence (FCS) field. The
information field contains the data to be transferred. Not every frame, however, must actually contain information
data. The word length of the I-field is eight bits in the S3C4510B HDLC module. And Its total length can be
extended by 8 bits until terminated by the FCS field and the closing flag.
Frame Check Sequence (FCS) Field
The 16 bits that precede the closing flag comprise the frame check sequence (FCS) field. The FCS field contains
the cyclic redundancy check character, CRCC. The polynomial x16 + x12 + x5 + 1 is used both for the
transmitter and the receiver. Both the transmitter and the receiver polynomial registers are all initialized to 1 prior
to calculating of the FCS. The transmitter calculates the frame check sequence of all address bits, control bits,
and information fields. It then transmits the complement of the resulting remainder as the FCS value.
The receiver performs a similar calculation for all address, control, and information bits, as well as for all the FCS
fields received. It then compares the result to F0B8H. When a match occurs, the frame valid (RxFV) status bit is
set to '1'. When the result does not match, the receiver sets the CRC error bit (RxCRCE) to '1'. The transmitter
and the receiver automatically perform these FCS generation, transmission and checking functions. The
S3C4510B HDLC module also supports NO CRC operation mode. In NO CRC mode, transmitter does not
append FCS to the end of data and the receiver also does not check FCS. In this mode, the data preceding the
closing flag is transferred to the HRXFIFO. In CRC mode, the FCS field is transferred to the HRXFIFO.
8-5
HDLC CONTROLLERS
S3C4510B
PROTOCOL FEATURES
INVALID FRAME
A valid frame must have at least the A, C, and FCS fields between its opening and closing flags. Even if no-CRC
mode is set, the frame size should not be less than 32 bits. There are three invalid frame conditions:
— Short frame: a frame that contains less than 25 bits between flags. Short frames are ignored.
— Invalid frame: a frame with 25 bits or more, having a CRC compare error or non- byte-aligned. Invalid frames
are transferred to the HRXFIFO, then the invalid frame error flag (RxCRCE, RxNO in the status register) is
set to indicate that an invalid frame has been received.
— Aborted frame: a frame aborted by the reception of an abort sequence is handled as an invalid frame.
ZERO INSERTION AND ZERO DELETION
The zero insertion and zero deletion feature, which allows the content of a frame to be transparent, is handled
automatically by the HDLC module. While the transmitter inserts a binary '0' following any sequence of five 1s
within a frame, the receiver deletes a binary '0' that follows a sequence of five 1s within a frame.
ABORT
The function of early termination of a data link is called an abort The transmitter aborts a frame by sending at
least eight consecutive 1s immediately after the abort transmitter control bit (TxABT in HCON) is set to '1'.
(Setting this control bit automatically clears the HTxFIFO.)
The abort sequence can be extended up to (at least) 16 consecutive 1s by setting the abort extend control bit
(TxABTEXT in HCON) to '1'. This feature is useful for forcing the mark idle state. The receiver interprets the
reception of seven or more consecutive 1s as an abort.
The receiver responds the abort received as follows:
— An abort in an 'out of frame' condition: an abort has no meaning during the idle or the time fill
— An abort 'in frame' after less than 25 bits are received after an opening flag: under this condition, no field of
the aborted frame is transferred to the HRXFIFO. The HDLC module clears the aborted frame data in the
receiver and flag synchronization. The aborted reception is indicated in the status register.
— An abort 'in frame' after 25 bits or more are received after an opening flag: in this condition, some fields of
the aborted frame may be transferred to the HRXFIFO. The abort status is set in the status register and the
data of the aborted frame in the HRXFIFO is cleared. Flag synchronization is also cleared and the DMA
operation for receiving is aborted too.
IDLE AND TIME FILL
When the transmitter is not transmitting a frame, it is in an idle state. The transmitter signals that it has entered
an idle state in one of the following two ways: 1) by transmitting a continuous series of flag patterns (time fill), or
2) by transmitting a stream of consecutive 1s (mark idle). The flags and mark idle are not transferred to the
HRXFIFO.
The flag or mark idle selection bit (TxFLAG in HCON) controls this function: when TxFLAG is '0', mark idle is
selected; when TxFLAGIDLE is '1', the time fill method is selected.
8-6
S3C4510B
HDLC CONTROLLERS
FIFO STRUCTURE
In both transmit and receive directions, 32-byte (8 word) deep FIFOs are provided for the intermediate storage of
data between the serial interface and the CPU Interface.
TWO-CHANNEL DMA ENGINE
The HDLC module has a two-channel DMA engine for Tx/Rx FIFOs. The DMA Tx channel programming and the
RX channel programming are described in the transmitter and receiver operation sections, respectively.
BAUD RATE GENERATOR
The HDLC module contains a programmable baud rate generator(BRG). The BRG register contains a 16-bit time
constant register, a 12-bit down counter for time constant value, two control bit to divide 16, and another two
control bits to divide 16 or 32.
A clock diagram of the BRG is shown in Figure 8-2.
At a start-up, the flip-flop on the output is set in a High state, the value in the time constant register is loaded into
the counter, and the counter starts counting down. The output of the baud rate generator may toggle upon
reaching zero, the value in the time constant register is loaded into the counter, and the process is repeated. The
time constant may be changed any time, but the new value does not take effect until the next load of the counter.
The output of the baud rate generator may be used as either the transmit clock, the receive clock, or both. It can
also drive the digital phase-locked loop. If the receive or transmit clock is not programmed to come from the TXC
pin, the output of the baud rate generator may be echoed out via the TXC pin.
The following formula relates the time constant to the baud rate where MCLK2 or RXC is the baud rate generator
input frequency in Hz. BRG generates 2 output signals, BRGOUT1, BRGOUT2, for transmit/receive clocks and
the DPLL input clock.
BRGOUT1 = (MCLK2 or RXC) / (CNT0 + 1) / (16CNT1
BRGOUT2 = BRGOUT1 / (1 or 16 or 32 according to CNT2 value of the HBRGTC)
)
CNT0
CNT1
CNT2
RxC
BRGOUT2
BRGOUT1
Divide by
1 or 16
Divide by
1 or 16 or 32
12-bit counter
MCLK2
CNT0: HBRGTC [15:4]
CNT1: HBRGTC [3:2]
CNT2: HBRGTC [1:0]
BRGCLK: HMODE [19]
BRGCLK
Figure 8-2. Baud Rate Generator Block Diagram
8-7
HDLC CONTROLLERS
S3C4510B
The example in the following Table assumes a 25 MHz clock from MCLK2, a 24.576 MHz clock from RxC,
showing a time constant for a number of commonly used baud rates.
Table 8-2. Baud Rate Example of HDLC
Baud Rate
(BRGOUT2)
1200
MCLK = 25 MHz
R´ C = 24.576 MHz
CNT0
1301
650
324
162
80
CNT1
CNT2
Freq. Dev.(%) CNT0
CNT1
CNT2
Freq.
Dev.(%)
0.0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1200.1
2400.2
4807.7
9585.9
19290.1
38109.8
57870.4
0.0
0.0
1279
639
319
159
79
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1200.0
2400.0
2400
0.0
4800
0.2
4800.0
0.0
9600
- 0.1
0.5
9600.0
0.0
19200
19200.0
38400.0
56888.9
118153.8
0.0
38400
40
- 0.8
0.5
39
0.0
57600
26
26
-1.2
2.6
115200
13
111607.1 - 3.1
12
8-8
S3C4510B
HDLC CONTROLLERS
DIGITAL PHASE-LOCKED LOOP (DPLL)
The HDLC module contains a digital phase-locked loop (DPLL) function to recover clock information from a data
stream with NRZI or FM encoding. The DPLL is driven by a clock that is normally 32 (NRZI) or 16 (FM) times the
data rate. The DPLL uses this clock, along with the data stream, to construct the clock.
This clock may then be used as the receive clock, the transmit clock, or both.
Figure 8-3 shows a block diagram of the digital phase-locked loop. It consists of a 5-bit counter, an edge detector
and a pair of output decoders.
Receive Clock
Transmit clock
RxD
Edge
Detector
Count Modifier
5-bit Counter
Decoder
Decoder
dplloutR
dplloutT
TxC
RxC
MCLK
BRGOUT1
BRGOUT2
HMODE[18:16]
Figure 8-3. DPLL Block Diagram
CLOCK USAGE METHOD
BRGCLK
DPLLCLK
TxC
RxC
BRGOUT1
BRGOUT2
DPLLOUTT
RxC
Baud Rate
Generator
DPLL
MCLK
MCLK2
BRGOUT1
BRGOUT2
DPLLORTR
TxCLK
RxCLK
TxC
TxC
RxC
DPLLOUTT
BRGOUT1
BRGOUT2
RxC
DPLLOUTT
BRGOUT1
BRGOUT2
Transmit
Transmit
Receive
Clock
Receive
Data
Transmitter
Receiver
Clock
Data
NOTE:
BRGCLK = HMODE [19]
DPLLCLK = HMODE [18:16]
TxCLK = HMODE [22:20]
RxCLK = HMODE [26:24]
Figure 8-4. Clock Usage Method Diagram
8-9
HDLC CONTROLLERS
S3C4510B
In the NRZ/NRZI mode, the DPLL source clock must be 32 times the data rates. In this mode, the transmit and
receive clock outputs of the DPLL are identical, and the clocks are phased so that the receiver samples the data
in the middle of the bit cell.
The DPLL counts the 32x clock using an internal 5-bit counter. As the 32x clock is counted, the DPLL searches
the incoming data stream for edges (either positive or negative transition). The output of DPLL is High while the
DPLL is waiting for an edge in the incoming data stream. When it detects a transition, the DPLL starts the clock
recovery operation.
The first sampling edge of the DPLL occurs at the counter value of 16 after the first edge is detected in the
incoming data stream. The second sampling edge occurs following the next 16. When the transition of incoming
data occurs at a count value other than 16, the DPLL adjusts its clock outputs during the next 0 to 31 counting
cycle by extending or shortening its count by one, which effectively moves the edge of the clock sampling the
receive data closer to the center of the bit cell.
The adding or subtracting of a count of 1 will produce a phase jitter of 5.63 degrees on the output. Because the
DPLL uses both edges of the incoming signal for its clock source comparison, the mark-space ratio (50%) of the
incoming signal must not deviate more than 1.5% of its baud rate if proper locking is to occur.
In the FM mode, the DPLL clock must be 16 times the data rate. The 5-bit counter in the DPLL counts from 0 to
31, so the DPLL makes two sampling clocks during the 0 to 31 counting cycle. The DPLL output is Low while the
DPLL is waiting for an edge in the incoming data stream. The first edge the DPLL detects is assumed to be a
valid clock edge. From this point, the DPLL begins to generate output clocks.
In this mode, the transmit clock output of the DPLL lags the receive clock outputs by 90 degrees to make the
transmit and receive bit cell boundaries the same, because the receiver must sample the FM data at a one-
quarter and three-quarters bit time.
You can program the 32X clock for the DPLL to originate from one of the RxC input pins, from the TxC pin, or
from the baud rate generator output. You can also program the DPLL output to be "echoed out" of the HDLC
module over the TXC pin(if the TXC pin is not being used as an input).
During idle time, you can set the TxPRMB in HCON to send the special pattern required for a remote DPLL to
lock the phase. In this case, the content of the HPRMB register is sent repeatedly. The length of preamble is
determined by TxPL bit in HMODE[10:8].
It is noticed that the frequency of the receive clock (RxC) should be slower than half of the internal system clock
i.e., MCLK/2. Otherwise, the data transfer from receive FIFO to memory could be lost.
8-10
S3C4510B
HDLC CONTROLLERS
HDLC OPERATIONAL DESCRIPTION
The following sections describe the operation of the HDLC module.
HDLC INITIALIZATION
A power-on or reset operation initializes the HDLC module and forces it into the reset state. After a reset, the
CPU must write a minimum set of registers, as well as any options set, based on the features and operating
modes required.
First, the configuration of the serial port and the clock mode must be defined. These settings include the
following:
— Data format select
— BRG clock select
— DPLL clock select
— Transmit clock select
— Receive clock select
— BRG/DPLL enable to use internal clock
You must also set the clock for various components before each component is enabled. Additional registers may
also have to be programmed, depending on the features you select. All settings for the HDLC mode register,
HMODE, and the HDLC control register, HCON, must be programmed before the HDLC is enabled.
To enable the HDLC module, you must write a '1' to the receiver enable bit and/or the transmitter enable bit.
During normal operation, you can disable the receiver or the transmitter by writing a '0' to the RxEN or TxEN bit,
respectively. You can disable the receiver and HRXFIFO or the transmitter and HTxFIFO by writing a '1' to the
RxRS or TxRS bit, respectively.
8-11
HDLC CONTROLLERS
S3C4510B
HDLC DATA ENCODING/DECODING
Data encoding is utilized to allow the transmission of clock and data information over the same medium. This
saves the need to transmit clocks and data over a separate medium as would normally be required for
synchronous data. The HDLC provides four different data encoding methods, selected by bits in HCON1[18:16].
An example of these four encoding methods is shown in figure 8-5.
Data
NRZ
Bit Cell Level:
1
1
0
0
1
0
High = 1
Low = 0
No Change = 1
Change = 0
NRZI
Bit Center Transition:
Transition = 1
No Transition = 0
FM1
(Biphase Mark)
FM0
(Biphase Space)
No Transition = 1
Transition = 0
High
Low
Low = 1
High = 0
Manchester
NRZ, NRZI Type
TxClock
Data
RxClock
FM0/FM1/Manchester type
TxClock
Data
RxClock
Figure 8-5. Data Encoding Methods and Timing Diagrams
8-12
S3C4510B
HDLC CONTROLLERS
HDLC DATA SETUP AND HOLD TIMING WITH CLOCK
You can see the timing of TxD and RxD in terms of TxC and RxC HDLC clock in Figure 8-6.
Table 8-3. HMODEA and HMODEB Register
Symbol
Ttxdf
Condition
TxD falling edge delay time
TxD falling edge delay time
Min
9.82
1.0
Typ
Max
Unit
ns
10.66
Trxdf
ns
40 ns
TxC
TxD
9.82 ns
10.66 ns
RxC
RxD
0.2 ns
1.0 ns
Figure 8-6. Data Encoding Methods and Timing Diagrams
Tx data will be sent with delayed 9.82 nsec to 10.66 nsec from the falling edge of Tx Clock. In case of RxD, the
black period should not be changed. That is, the RxD should be stable from 0.2nsec to 1.0nsec after RxC rising
edge. (It does not allow data transition during this period) The RxC will be Rx(receiver) clock through Rx clock
selection part with some delay. And this RxC delay is larger then RxD delay. In Figure 8-6, the dotted-clock is
real internal Rx clock used by the receiver. Therefore, there should not be transit in Rx data to avoid setup or
hold violation.
8-13
HDLC CONTROLLERS
S3C4510B
HDLC TRANSMITTER OPERATION
The HTxFIFO register cannot be pre-loaded when the transmitter is disabled. After the HDLC Tx is enabled, the
flag or mark idle control bit (TxFLAG in HCON) is used to select either the mark idle state (inactive idle) or the
flag 'time fill' (active idle) state. This active or inactive idle state will continue until data is loaded into the
HTxFIFO.
The content of the HPRMB register can be sent out by setting the TxPRMB in HCON for the remote DPLL before
the data is loaded into the HTxFIFO. The length of preamble to be transmitted is determined by TxPL bits in
HMODE.
The availability of data in the HTxFIFO is indicated by the HTxFIFO available bit (TxFA in HSTAT) under the
control of the 4-word transfer mode bit (Tx4WD in HCON).
When you select 1-word transfer mode (not 4-word select mode), one word can be loaded into the HTxFIFO
(assuming the TxFA bit is set to '1'). When you select 4-word transfer mode, four successive words can be
transferred to the FIFO if the TxFA bit is set to '1'.
The nCTS (clear-to-send) input, nRTS (request-to-send), and nDCD (data-carrier-detect) are provided for a
modem or other hardware peripheral interface.
In auto enable mode, nDCD becomes the receiver enable. However, the receiver enable bit must be set before
the nDCD pin is used in this manner.
The TxFC status bit(in HSTAT) can cause an interrupt to be generated upon frame completion (This bit is set
when there is no data in HTxFIFO and when the closing flag or an abort is transmitted).
8-14
S3C4510B
HDLC CONTROLLERS
Transmitter Interrupt Mode
The first byte of a frame (the address field) should be written into the Tx FIFO at the 'frame continue' address.
Then, the transmission of the frame data starts automatically. The bytes of the frame continue to be written into
the Tx FIFO as long as data is written to the 'frame continue' address. The HDLC logic keeps track of the field
sequence within the frame.
The frame is terminated when the last frame data is written to the Tx FIFO's 'frame terminate' address. The FCS
field is automatically appended by hardware, along with a closing flag. Data for a new frame can be loaded into
the Tx FIFO immediately after the previous frame data, if TxFA is '1'. The closing flag can serve as the opening
flag of the next frame or separate opening and closing flags can be transmitted. If a new frame is not ready to be
transmitted, a flag time fill or mark idle pattern is transmitted automatically.
If the Tx FIFO becomes empty at any time during the frame transmission, an underrun occurs and the transmitter
automatically terminates the frame by transmitting an abort. The underrun state is indicated when the transmitter
underrun status bit (TxU) is '1'.
Whenever you set the transmission abort control bit (TxABT in HCON), the transmitter immediately aborts the
frame (transmits at least eight consecutive 1s), clearing the Tx FIFO. If the transmission abort extension control
bit (TxABTEXT) is set at the time, an idle pattern (at least 16 consecutive 1s) is transmitted. An abort or idle in an
out- of-frame condition can be useful to gain 8 or 16 bits of delay time between read and write operations.
Transmitter DMA Mode
To use DMA operation without CPU intervention, you have to make Tx buffer descriptor chain in advance. And
set the DMA Tx buffer descriptor pointer (DMATxPTR) register to the address of the first buffer descriptor of the
chain, and then DMA Tx channel should be enabled.
When Tx underrun or CTS lost condition occurs during DMA operation, DMA Tx enable bit(HCON[6]) is cleared
and DMA Tx operation is stopped. This situation is reported to system with DTxABT bit set (HSTAT[22]).
In case of Tx underrun, abort signal sent and then idle pattern is sent if TxEN bit is set. In case of CTS lost, TxD
output goes high state as long as CTS remains high level.
8-15
HDLC CONTROLLERS
S3C4510B
HDLC RECEIVER OPERATION
The HDLC receiver is provided with data and a pre-synchronized clock by means of the RxD and the internal
DPLL clock, the TxC pin, or the RxC pin. The data is a continuous stream of binary bits. One of the
characteristics of this bit stream is that a maximum of five consecutive 1s can occur unless an abort, flag, or idle
condition occurs. The receiver continuously searches (bit-by-bit) for flags and aborts.
When a flag is detected, the receiver synchronizes the frame to the flag timing. If a series of flags is received,
the receiver re-synchronizes the frame to each successive flag.
If the frame is terminated because of a short frame condition (frame data is less than 32 bits after an opening
flag), the frame is simply ignored. Noise on the data input line (RxD) during time fill can cause this kind of invalid
frame.
The received data which is clocked by the external TxC or RxC, or by an internal DPLL or BRG source enters a
56-bit or 32-bit shift register before it is transferred into the HRXFIFO. Synchronization is established when a flag
is detected in the first eight locations of the shift register. When synchronization has been achieved, data is
clocked through to the last byte location of the shift register where it is transferred into the HRxFIFO.
In 1-word transfer mode, when the HRxFIFO available bit (RxFA) is '1', data is available at least in one-word. In
4-word transfer mode, the RxFA is '1' when data is available in the last four FIFO register locations (registers 4,
5, 6, and 7). The nDCD input is provided for a modem or other hardware interface. If AutoEN bit in HCON[28] is
set to '1', the receiver operation is dependent on the nDCD input level.
Otherwise, receiver operation is free of the nDCD input level.
Receiver Interrupt Mode
Whenever data is available in the HRXFIFO, an interrupt is generated by RxFA (if the interrupt is enabled). The
CPU reads the HDLC status register either in response to the interrupt request or in turn during a polling
sequence.
When the received data available bit(RxFA) is '1', the CPU can read the data from the HRXFIFO. If the CPU
reads normal data or address data from the HRXFIFO, the RxFA bit is automatically cleared.
In CRC mode, the 16 bits preceding the closing flag are regarded as the FCS and checked by hardware, and they
are transferred to the HRXFIFO. Also, in no CRC mode, without the hardware checking, all data bits preceding
the closing flag are transferred to the HRXFIFO. When the closing flag is sent to the receiver, the frame is
terminated. Whatever data is present in the most significant byte of the receiver, the shift register is right justified
and transferred to the HRXFIFO. The frame boundary pointer, which is explained in the HRXFIFO register
section, is set simultaneously in the HRXFIFO. When the last byte of the frame appears at the 1-word or 4-word
boundary location of the HRXFIFO, depending on the settings of the Rx4WD control bit, the frame boundary
pointer sets the frame valid status bit (if the frame is completed with no error) or the RxCRCE status bit(if the
frame was completed, but with a CRC error).
If the frame reception is completed, an RxCRCE interrupt (for a frame error) or an RxFV interrupt (for normal
state) is generated. At this point, the CPU can read the Rx remaining bytes (RxRB) status bits to know how many
bytes of this frame still remain in the HRXFIFO.
When you set the frame discontinue control bit (the incoming frame discard control bit) to '1', the receiver
discards the current frame data without dropping the flag synchronization. You can use this feature to ignore a
frame with a non-matched address.
8-16
S3C4510B
HDLC CONTROLLERS
Receiver DMA Mode
To use DMA operation without CPU intervention, you have to make Rx buffer descriptor chain in advance. And
set the DMA Rx buffer descriptor pointer (DMARxPTR) register to the address of the first buffer descriptor of the
chain, and then DMA Rx channel should be enabled.
HARDWARE FLOW CONTROL
TxClock
TxD
last
RTS
CTS
Figure 8-7. nCTS Already Asserted
When nCTS is active and there exists data to be transmitted in Tx FIFO, nRTS enters Low, allowing data
transmission. At the beginning of the data is an open flag while at the end a closing flag. If the frame being
transferred discontinues, nRTS goes back to the High after the data transmission is completed.
TxClock
TxD
RTS
CTS
Data
5-13 cycles
14 - 22 cycles
Figure 8-8. CTS Lost during Transmission
When the condition of nCTS is shifted from Low to High, it is detected at the falling edge of Tx clock, where
nRTS also goes High. For about 5 to 13 cycles after nRTS enters High, the data transmission continues. nRTS
remains High for a maximum of 22 cycles and goes back to the Low condition if there remains any data to be
transmitted in HTxFIFO. If nCTS is still High even when nRTS went back to Low, not the data in HTxFIFO but a
mark idle pattern is transmitted when AutoEn bit set to one.
8-17
HDLC CONTROLLERS
S3C4510B
TxClock
TxD
Data
5 - 12 cycles
RTS
CTS
Figure 8-9. CTS Delayed on
If nCTS remains still High for a while after nRTS enters Low to allow data transmission from HTxFIFO, the data
transmission starts 5-12 cycles after nCTS is shifted to Low
8-18
S3C4510B
HDLC CONTROLLERS
MEMORY DATA STRUCTURE
The flow control to the HDLC controller uses two data structures to exchange control information and data.
— Transmit buffer descriptor
— Receive buffer descriptor
Each Tx DMA buffer descriptor has the following elements.
— Buffer data pointer
— Ownership bit
— Control field for transmitter
— Status field for Tx
— Transmit buffer length
— Next buffer descriptor pointer
Each Rx DMA buffer descriptor has the following elements.
— Buffer data pointer
— Ownership bit
— Status field for Rx
— Accumulated received buffer length for a frame
— Next buffer descriptor pointer
8-19
HDLC CONTROLLERS
S3C4510B
DATA BUFFER DESCRIPTOR
The ownership bit in the MSB of the buffer data pointer controls the ownership of the descriptor. When the
ownership bit is '1', the DMA controller owns the descriptor. When this bit is '0', the CPU has the descriptor. The
owner of the descriptor always owns the associated data frame. (The descriptor's buffer data pointer field always
points to this buffer for about a frame.)
As it receives the data, the software sets the maximum frame length register. If the received data is longer than
the value of the maximum frame length register, this frame is ignored and the FLV bit is set. The software also
sets the DMA Rx buffer descriptor pointer to point to a chain of buffer descriptors, all of which have their
ownership bit.
The DMA controller can be started to set the DMA Rx enable bit in the control register. When a frame is
received, it is moved into memory at the address specified by the DMA Rx data buffer pointer. If a frame is
longer than the value of the RxBuf Size register, then the next buffer descriptors are fetched to receive the
frame.
That is, to handle a frame, one or more buffer descriptors could be used. Please note that no configurable offset
or page boundary calculation is required. The received frame is moved to the buffer memory whose address is
pointed to by the buffer data pointer until the end of frame, or until the length exceeds the maximum frame length
configured.If the length exceeds the maximum frame length configured, the frame length violated bit is set.
If the entire frame is received successfully, the status bits in the receive buffer descriptor are set to indicate the
received frame status. The ownership bit in the buffer descriptor pointer is cleared by the CPU which has the
ownership and an interrupt may now be generated. The DMA controller copies the next buffer descriptor pointer
into the DMA Rx buffer descriptor pointer register.
If the next buffer descriptor pointer is null(0), the DRxEN bit is cleared, and DMA Rx operation is stopped.
Otherwise, the descriptor is read, and the DMA controller starts again with the next data, as described in the
previous paragraph.
When the DMA reads a descriptor, if the ownership bit is not set, it has two options:
— Skip to the next buffer descriptor when DRxSTSK bit is '0'
— Generate an interrupt and halt the DMA operation when DRxSTSK bit is '1'
During transmission, the two-byte frame length at the Tx buffer descriptor is moved to the DMA internal Tx
register. After transmission, the Tx status is saved in the Tx buffer descriptor. The DMA controller then updates
the next buffer descriptor pointer for the linked list structure.
When the DMA Tx buffer descriptor register points to the first buffer descriptor, the transmitter starts transmitting
the frame data from the buffer memory to Tx FIFO.
8-20
S3C4510B
HDLC CONTROLLERS
BUFFER DESCRIPTOR
TRANSMIT BUFFER DESCRIPTOR
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8 7 6 5 4 3 2 1 0
O
Buffer Data Pointer
Reserved
WA D L E N P
Reserved
T
Buffer Length
Next Buffer Descriptor Pointer
[30:0] Buffer Data Pointer
[31] Ownership (O)
0 = CPU
1 = DMA
Tx Control Bits
[0] Preamable (P)
0 = No preamble
1 = Preamble
[1] TxNoCRC Mode (N)
0 = CRC mode
1 = No CRC mode
1 = Little-endian
[2] Little-Endian Mode (E)
0 = Big-endian
[3] Last (L)
0 = This is not the last buffer in the frame.
1 = This is the last buffer in the frame.
[4] Buffer Data Pointer Decrement (D)
0 = Increment
1 = Decrement
[6:5] Widget Aligment Control (WA)
00 = No invalid bytes
10 = 2 invalid bytes
01 = 1 invalid bytes
11 = 3 invalid bytes
[23:0] Buffer Length
Tx Status Bit
These bit may be regarded as valid when the L bit (in Tx control bit) is set.
[26] Transmission Completion (T)
0 = Normal
1 = One frame completed
[31:0] Next Buffer Descriptor Pointer
The address of the next buffer descriptor
Figure 8-10. Transmit Buffer Descriptor
8-21
HDLC CONTROLLERS
S3C4510B
RECEIVE BUFFER DESCRIPTOR
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
O
Buffer Data Pointer
Reserved
F
L
V
A D
L F B T
T M
Reserved
O N C
V O D
Buffer Length
Next Buffer Descriptor Pointer
[30:0] Buffer Data Pointer
[31] Ownership (O)
0 = CPU
1 = DMA
[15:0] Buffer Length
Received buffer lengths are wrote to this buffer descriptor
Rx Status Bits
This bits may be regarded as valid when L bit (in Rx status bit) is set.
[16] CD Lost (CD)
0 = Normal
1 = CD lost occurs
[17] CRC Error (CE)
0 = Normal
1 = CRC error occurs to the frame received.
[18] Non-octet Aligned Frame (NO)
0 = Normal
1 = Non-octet aligned frame is reveived.
[19] Over-run (OV)
0 = Normal
1 = The reveived frame overruns.
[20] DPLL Two Miss (DTM)
0 = Normal
1 = DPLL two miss clock occurs.
[21] Rx Abort (ABT)
0 = Normal
1 = The received frame aborted.
[22] First In Frame (F)
0 = This buffer descriptor status is not the first to the frame.
1 = This buffer descriptor status is the first to the frame.
[23] Last In Frame (L)
0 = This buffer descriptor status is not the last to the frame.
1 = This buffer descriptor status is the first to the frame.
[24] Frame Length Violation (FLV)
0 = Normal
1 = This received frame length exceeds the value of the maximum frame length register.
[31:0] Next Buffer Descriptor Pointer
The address of the next buffer descriptor
Figure 8-11. Receive Buffer Descriptor
8-22
S3C4510B
HDLC CONTROLLERS
Rx Buffer
Descriptor
Start Address
Pointer
Buffer Data Pointer #1
Reserved
Rx Bufsize
Register
Value
Buffer Data #1
Unused
Status
Buffer Length
Next Buffer Descriptor
Rx Bufsize
Register
Value
Buffer Data Pointer #2
Reserved
Buffer Data #2
Unused
Status
Buffer Length
Next Buffer Descriptor
Buffer Data #N
Unused
Buffer Data Pointer #N
Reserved
Status
Buffer Length
In single linked lists, the next buffer
descriptor is filled with a null
address.
Next Buffer Descriptor
NOTE:
Buffer length is accumulated until the last bit is set in STATUS.
Buffer data pointer indicates the buffer memory start address.
Figure 8-12. Data Structure of the Receive Data Buffer
8-23
HDLC CONTROLLERS
S3C4510B
HDLC SPECIAL REGISTERS
The HDLC special registers are defined as read-only or write-only registers according to the direction of
information flow. The addresses of these registers are shown in Table 8-4 and 8-5.
The transmitter FIFO register can be accessed using two different addresses, the frame terminate address and
the frame continue address. The functions of these addresses are discussed in detail in the FIFO section below.
Table 8-4. HDLC Channel A Special Registers
Registers
HMODE
Offset
0´ 7000
R/W
R/W
R/W
R/W
R/W
W
Description
HDLC mode register
Reset Value
0´ 00000000
0´ 00000000
0´ 00000000
0´ 00000000
–
HCON
HDLC control register
0´ 7004
0´ 7008
0´ 700c
0´ 7010
HSTAT
HINTEN
HDLC status register
HDLC interrupt enable register
HTxFIFO frame continue register
HTxFIFOC
(Frame Continue)
HTxFIFOT
(Frame
W
HTxFIFO frame terminate register
–
0´ 7014
Terminate)
HRxFIFO
HBRGTC
HPRMB
R
HRxFIFO entry register
0´ 7018
0´ 701c
0´ 7020
0´ 7024
0´ 7028
0´ 702c
0´ 7030
0´ 7034
0´ 7038
0´ 703c
0´ 7040
0´ 7044
0´ 00000000
0´ 00000000
0´ 00000000
0´ 00000000
0´ 00000000
0´ 00000000
0´ 00000000
0´ 00000000
0´ FFFFFFFF
0´ FFFFFFFF
0´ XXXX0000
0´ XXXX0000
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
HDLC BRG time constant register
HDLC preamble register
HSAR0
HDLC station address 0
HSAR1
HDLC station address 1
HSAR2
HDLC station address 2
HSAR3
HDLC station address 3
HMASK
HDLC mask register
HDMATxPTR
HDMARxPTR
HMFLR
DMA Tx buffer descriptor pointer
DMA Rx buffer descriptor pointer
Maximum frame length register
Receive buffer size register
HRBSR
8-24
S3C4510B
HDLC CONTROLLERS
Table 8-5. HDLC Channel B Special Registers
Registers
Offset
0´ 8000
R/W
R/W
R/W
R/W
R/W
W
Description
HDLC mode register
Reset Value
0´ 00000000
0´ 00000000
0´ 00000000
0´ 00000000
–
HMODE
HCON
HDLC control register
0´ 8004
0´ 8008
0´ 800c
0´ 8010
HSTAT
HINTEN
HDLC status register
HDLC interrupt enable register
HTxFIFO frame continue register
HTxFIFOC
(Frame Continue)
HTxFIFOT
(Frame
W
HTxFIFO frame terminate register
–
0´ 8014
Terminate)
HRxFIFO
HBRGTC
HPRMB
R
HRxFIFO entry register
0´ 8018
0´ 801c
0´ 8020
0´ 8024
0´ 8028
0´ 802c
0´ 8030
0´ 8034
0´ 8038
0´ 803c
0´ 8040
0´ 8044
0´ 00000000
0´ 00000000
0´ 00000000
0´ 00000000
0´ 00000000
0´ 00000000
0´ 00000000
0´ 00000000
0´ FFFFFFFF
0´ FFFFFFFF
0´ XXXX0000
0´ XXXX0000
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
HDLC BRG time constant register
HDLC preamble register
HSAR0
HDLC station address 0
HSAR1
HDLC station address 1
HSAR2
HDLC station address 2
HSAR3
HDLC station address 3
HMASK
HDLC mask register
HDMATxPTR
HDMARxPTR
HMFLR
DMA Tx buffer descriptor pointer
DMA Rx buffer descriptor pointer
Maximum frame length register
Receive buffer size register
HRBSR
8-25
HDLC CONTROLLERS
S3C4510B
HDLC GLOBAL MODE REGISTER
Table 8-6. HMODEA and HMODEB Register
Registers
HMODEA
HMODEB
Offset
0´ 7000
0´ 8000
R/W
R/W
R/W
Description
HDLC Mode register
HDLC Mode register
Reset Value
0´ 00000000
0´ 00000000
Table 8-7. HMODE Register Description
Description
Bit
Bit Name
Number
[0]
Multi-Frame in HTxFIFO If this bit is set, more than one frame can be loaded into HTxFIFO. In this
in DMA operation (MFF) case, the frame size may be less than the FIFO size.
[1]
[2]
Reserved
Not applicable.
Rx clock
inversion(RXCINV)
If this bit set to '0', the receive clock samples the data at the rising edge.
If this bit set to '1', the receive clock samples the data at the falling edge.
[3]
[4]
Tx clock
inversion(TXCINV)
If this bit set to '0', the transmit clock shifts the data at the falling edge.
If this bit set to '1', the transmit clock shifts the data at the rising edge.
Rx Little-Endian mode
(RxLittle)
This bit determines whether the data is in Little- or Big-endian format.
HRXFIFO is in Little-endian. If this bit is set to '0', then the data on the
system bus should be in Big-endian. Therefore the bytes will be swapped
in Big- endian.
[5]
Tx Little-Endian mode
(TxLittle)
This bit determines whether Tx data is in Little or Big endian (TxLittle)
format. HTxFIFO is in Little-endian. If this bit is set to '1', the data on the
system bus is Little endian. If this bit is set to '0', the data on the system
bus is in Big-endian. (that is, the data bytes are swapped to be Little
endian format.)
[7:6]
Reserved
Not applicable
[10:8] Tx preamble
length(TxPL)
These bits determine the length of preamble to be sent before the opening
flag when the TxPRMB bit is set in the control register.
000 1byte, 001 2bytes,and 111 8bytes will be sent.
Not applicable
[11]
Reserved
[14:12] Data formats (DF)
When the DF bits are '000', data is transmitted and received in the NRZ
data format. When DF is '001', the NRZI (zero complement) data format is
selected. DF = '010' selects the FM0 data format, DF = '011' the FM1 data
format, and DF = '100' the Manchester data format.
[15]
Reserved
Not applicable
[18:16] DPLL clock select
(DPLLCLK)
Using this setting, you can configure the clock source for DPLL to one of
the following pins: TxC, RxC, MCLK, BRGOUT1, or BRGOUT2. To select
one of these pins, set the DPLLCLK bits to '000', '001', '010', '011', or '100',
respectively.
8-26
S3C4510B
HDLC CONTROLLERS
Table 8-7. HMODE Register Description (Continued)
Description
Bit
Bit Name
Number
[19]
BRG clock select
(BRGCLK)
If this bit is '1', MCLK2 is selected as the source clock for the baud rate
generator (BRG). If this bit is '0', the external clock at the RXC pin is
selected as the BRG source clock.
[22:20] Tx clock select (TxCLK) Using this setting, you can configure the transmit clock source to one of the
following pins: TxC, RxC, DPLLOUTT, BRGOUT1, or BRGOUT2.
To select one of these pins, set the TxCLK bits to '000', '001', '010', '011',
or '100', respectively.
[26:24] Rx clock select (RxCLK) Using this setting, you can configure the receive clock source to one of the
following pins: TXC, RXC, DPLLOUTR, BRGOUT1, or BRGOUT2.
To select one of these pins, set the RxCLK bits to '000', '001', '010', '011',
or '100', respectively.
[30:28] TxC output pin select
(TxCOPS)
If you do not use the clock at the TxC pin as the input clock, you can use
the TxC pin to monitor TxCLK, RxCLK, BRGOUT1, BRGOUT2,
DPLLOUTT, and DPLLOUTR. To select the clock you want to monitory,
set the TXCOPS to '000', '001', '010', '011', or '100', respectively.
[31]
Reserved
Not applicable.
8-27
HDLC CONTROLLERS
S3C4510B
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
T
x
L
i
R
x
L
i
R
x
C
I
B
R
G
C
L
T
x
C
I
M
F
F
TXC
OPS
DPLL
CLK
RxCLK
TxCLK
DF
TxPL
t
t
t
t
N
N
l
K
l
V V
e
e
[0] Muilt-Frame in TxFIFO in DMA Operation (MFF)
0 = Single frame in TxFIFO
1 = Multi frame in TxFIFO
[1] Reserved
[2] Rx Clock Inversion (RxCINV)
0 = Rx clock rising
1 = Rx clock falling
[3] Tx Clock Inversion (TxCINV)
0 = Tx clock falling
1 = Tx clock rising
[4] Rx Little-Endian Mode (RxLittle)
0 = The Rx data on the system bus is in Big-Endian format.
1 = The Rx data on the system bus is in Little-Endian format.
[5] Tx Little-Endian Mode (TxLittle)
0 = The Tx data on the system bus is in Big-Endian format.
1 = The Tx data on the system bus is in Little-Endian format.
[7:6] Reserved
[10:8] Tx Preamble Length (TxPL)
000 = 1 byte
001 = 2 byte
010 = 3 byte
011 = 4 byte
100 = 5 byte
101 = 6 byte
110 = 7 byte
111 = 8 byte
[11] Reserved
[14:12] Data Format (DF)
000 = NRZ data format
010 = FM0
001 = NRZI
001 = FMI
100 = Machester
[15] Reserved
[18:16] DPLL Clock Select (DPLLCLK)
000 = TXC pin
001 = RXC pin
010 = MCLK
011 = BRGOUT1
100 = BRGOUT2
[19] BRG Clock Select (BRGCLK)
0 = RXC pin is selected.
1 = MCLK2 is selected.
[22:20] Tx Clock Select (TxCLK)
000 = TXC pin
001 = RXC pin
010 = DPLLOUTT
100 = BRGOUT2
[27] Reserved
011 = BRGOUT1
[30:28] TXC Output Pin Select (TXCOPS)
This pin is used for output only when it is not used as an input clock for th
DPLL, TxCLK, or RxCLK.
000 = Tx clock
001 = Rx clock
010 = BRGOUT1
100 = DPLLOUTT
[31] Reserved
011 = BRGOUT2
101 = DPLLOUTR
Figure 8-13. HMODE Register
8-28
S3C4510B
HDLC CONTROLLERS
HDLC CONTROL REGISTER
Table 8-8. HCONA and HCONB Register
Registers
HCONA
HCONB
Offset
R/W
R/W
R/W
Description
Reset Value
0x00000000
0x00000000
HDLC channel A control register
HDLC channel B control register
0´ 7004
0x8004
Table 8-9. HCON Register Description
Description
Bit
Bit Name
Number
[0]
Tx reset (TxRS)
Rx reset (RxRS)
Set this bit to '1' to reset the Tx block. Tx block comprises HTxFIFO and a
transmitter block.
[1]
Set this bit to '1' to reset the Rx block. Rx block comprises HRXFIFO and a
receiver block.
[2]
[3]
[4]
DMA Tx reset (DTxRS) Set this bit to '1' to reset the DMA Tx block.
DMA Rx reset (DRxRS) Set this bit to '1' to reset the DMA Rx block.
Tx enable (TxEN)
When the TxEN bit is '0', the transmitter enters a disabled state and the
line becomes high state. In this case, the transmitter block is cleared
except for the HTxFIFO and the status bits associated with transmit
operation are cleared. Data cannot be loaded into the HTxFIFO.
If this bit is set to '1', the idle pattern is sent continuously. In this case, the
data can be loaded into HTxFIFO, and then sent.
[5]
[6]
Rx enable (RxEN)
When the RxEN bit is '0', the receiver enters a disabled state and can not
detect the flag pattern, if any. In this case, receiver block is cleared except
for the HRXFIFO and the status bits associated with receiver operation are
cleared. Data cannot be received.
If this bit is set to '1', the flag pattern is detected. In this case, the data
received can be loaded into the HRXFIFO, and moved to system memory.
DMA Tx enable
(DTxEN)
The DTxEN bit lets the HDLC Tx operate on a bus system in DMA mode.
When DMA Tx is enabled, an interrupt request caused by TxFA status is
inhibited and the HDLC does not use the interrupt request to request a data
transfer. DMA Tx monitors the HTxFIFO and fills the HTxFIFO. This bit is
auto disabled when Tx underrun occurs, or CTS lost, or next buffer
descriptor pointer reach null, or the owner bit is not DMA mode when
DTxSTSK bit is set. If Tx underrun occurs, DTxABT(in HSTAT) bit set, and
abort signal sended. If CTS lost occurs, DTxABT bit set and TxD output
goes high state as long as CTS remains high level.
8-29
HDLC CONTROLLERS
S3C4510B
Table 8-9. HCON Register Description (Continued)
Bit Name Description
Bit
Number
[7]
DMA Rx enable
(DRxEN)
The DRxEN bit lets the HDLC Rx operate on a bus system in DMA mode.
When DMA Rx is enabled, an interrupt request caused by the RxFA status
is inhibited, and the HDLC does not use the interrupt request to request a
data transfer. DMA Rx monitors the HRXFIFO and moves the data from
the HRXFIFO to memory. This bit is automatically disabled when the next
buffer descriptor pointer becomes null, or the owner bit is not in DMA mode
when the DTxSTSK bit is set.
[8]
DPLL enable (DPLLEN) Setting this bit enables the DPLL, causing the DPLL to enter search mode.
In Search mode, the DPLL searches for a locking edge in the incoming
data stream.
After DPLL is enabled (in NRZI mode for example), the DPLL starts
sampling immediately after the first edge is detected. (In FM mode, the
DPLL examines the clock edge of every other bit to decide what correction
must be made to remain in sync.) If the DPLL does not detect an edge
during the expected window, it sets the one clock missing bit.
If the DPLL does not detect an edge after two successive attempts, it sets
the two clock missing bit and the DPLL automatically enters the Search
mode. To reset both clocks missing latches, you can disable and re-enable
the DPLL using the reset Rx status.
[9]
BRG enable (BRGEN)
This bit controls the operation of the baud rate generator (BRG). To enable
the BRG counter, set the BRGEN bit to '1'. To inhibit counting, clear the bit
to '0'.
[10]
Tx 4 word mode
(Tx4WD)
When this bit is '0', and TxFA bit in status register is '1', it is indicated that
Tx FIFO is empty for 1 word. It means that 1-word data can be loaded to
Tx FIFO.
Similarly, when this bit is '1', the same status register bit indicate that 4
words of data can be loaded to Tx FIFO without reading the status bit for a
second time.
Specifically, the status register bit affected by the 1-word or 4-word transfer
setting are the transmit data available (TxFA) bit.
[11]
Rx 4 word mode
(Rx4WD)
When this bit is '0', and the RxFA bit in the status register is '1', it is
indicated that Rx FIFO has 1-word data. It means that 1 word data can be
moved to memory.
Similarly, when this bit is '1', the same status register bit indicates that 4
words of data can be moved in the memory without reading the status bit
for a second time.
Specifically, the status register bit affected by the 1-word or 4-word transfer
setting are the receive data available (RxFA) bit, and the residue bytes
status bits, RxRB[3:0].
8-30
S3C4510B
HDLC CONTROLLERS
Table 8-9. HCON Register Description (Continued)
Bit Name Description
Bit
Number
[13:12] Rx widget alignment
(RxWA)
These bits determine how many bytes are invalid in the first memory word
of the frame to be received. The invalid bytes are inserted when the word
is assembled in the HRXFIFO. '00' =No Invalid bytes;
'01' = 1 invalid byte, '10' = 2 invalid bytes, '11' = 3 invalid bytes.
[14]
[15]
[16]
[17]
DMA Tx stop or skip
(DTxSTSK)
This bit determines a DMA Tx stop or skip when DMA has not the
ownership associated with the Tx buffer descriptor. DMA Tx is disabled in
this condition when this bit is set.
DMA Rx stop or skip
(DRxSTSK)
This bit determines a DMA Rx stop or skip when DMA has not the
ownership associated with the Rx buffer descriptor. If this bit is set, DMA
Rx is disabled.
DMA Rx memory
address decrement
(DRxMADEC)
This bit determines whether the address is incremented or decremented. If
this bit is set to '1', then the address will be decremented.
Tx flag idle (TxFLAG)
This bit selects the flag 'time fill' mode (active idle) or the mark idle mode
(inactive idle) for the transmitter. The selected active or inactive idle state
continues until data is sent (after nRESET has return to High level). The
flag idle pattern is 7EH; the mark idle pattern is FFH.
[18]
[19]
Tx single flag
(TxSFLAG)
This bit controls whether separate closing and opening flags are
transmitted in succession to delimit frames. When this bit is '0',
independent opening and closing flags are transmitted in order to separate
frame.
When this bit is set to '1', the closing flag of the current frame serves as
the opening flag of the next frame.
Tx loop-back mode
(TxLOOP)
This bit is used for self-testing. If this bit is set to '1', the transmit data
output (TxD) is internally connected to the receiver data input (RxD). In
Loop-back mode, nCTS and nDCD inputs are ignored. For normal
operation, this bit should always be '0'.
[20]
[21]
[22]
Rx echo mode
(RxECHO)
Setting this bit to '1' selects the auto-echo mode of operation. In this mode,
the TxD pin is connected to RxD as in local loop-back mode, but the
receiver still monitors the RxD input.
Tx abort extension
(TxABTEXT)
When this bit is set to '1', the abort pattern that is initiated when TxABT =
'1' is extended to at least 16 bits of 1s in succession, and the mark idle
state is entered.
Tx abort (TxABT)
When this bit is set to '1', an abort sequence of at least eight bits of 1s is
transmitted. The abort is initiated and the HTxFIFO is cleared. TxABT is
then cleared automatically by hardware.
8-31
HDLC CONTROLLERS
S3C4510B
Table 8-9. HCON Register Description (Continued)
Bit Name Description
Bit
Number
[23]
Tx preamble (TxPRMB) When this bit is set to '1', the content of the HPRMB register is transmitted
as many TxPL bit values in interrupt mode instead of mark idle or time fill
mode. This is useful for sending the data needed by the DPLL to lock the
phase. In DMA mode, this bit is meaningless.
[24]
[25]
Tx data terminal ready
(TxDTR)
The TxDTR bit directly controls the nDTR output state. Setting this bit
forces the nDTR pin to Low level. When you clear the TxDTR bit, nDTR
goes High.
Rx frame discontinue
(RxDISCON)
When this bit is set, the frame currently received is ignored and the data in
this frame is discarded. Only the last frame received is affected. There is
no effect on subsequent frames, even if the next frame enters the receiver
when the discontinue bit is set. This bit is automatically cleared after a
cycle.
[26]
[27]
[28]
Tx no CRC (TxNOCRC) When this bit is set to '1', the CRC is not appended to the end of a frame
by hardware.
Rx no CRC (RxNOCRC) When this bit is set to '1', the receiver does not check for CRC by
hardware. (CRC data is always moved to the HRxFIFO.)
Auto enable (AutoEN)
This bit programs the function of both nDCD and nCTS. However, TxEN
and RxEN must be set before the nCTS and nDCD pins can be used.
When this bit is '0', if the nCTS becomes high, the transmitter sends mark
idle pattern. However, though the nDCD becomes high, the receiver can
receive the data.
When this bit is '1', if the nCTS becomes high, the transmitter send mark
idle but clears the HTxFIFO and the Tx block. If nDCD becomes high, the
receiver can't operate, and the HRxFIFO and Rx blocks are cleared.
[31:29] Reserved
Not applicable.
8-32
S3C4510B
HDLC CONTROLLERS
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4 3 2 1 0
A R T R T T T
R T T T D D D
R
x
W
A
R T B
R
x
D D D
P R T
T D D R T
x R T
T
x
u
t
x
x
x
x
x
x
x
x
x
x R R T
x
4
x R
4 G
x x
N N D D P A
E L S F
x
x
x
E
L
x
x
E x x R R
A
B
T
E
X
T
o O O
I
T R B
C O F L M S S
H O L A A T T
O P A G D S S
W W E
D D N
N N R R S S
S S
L E E
E N N
N
E C C S R M T
N R R C
C C O
N
B
G
E K K
C
[0] Tx reset (TxRS)
0 = Normal
[1] Rx reset (RxRS)
0 = Normal operation
[2] DMA Tx reset (DTxRS)
0 = Normal operation
[3] DMA Rx reset (DRxRS)
0 = Normal operation
1 = TxFIFOmand Tx block are reset.
1 = RxFIFO and Rx block are reset.
1 = DMA Tx block is reset.
1 = DMA Rx block is reset.
1 = Tx enabled
[4] Tx enable (TxEN)
0 = Tx disabled
[5] Rx enable (RxEN)
0 = Rx disabled
1 = Rx enabled
[6] DMA Tx enable (DTxEN)
0 = DMA Tx disabled
1 = DMA Tx enabled
[7] DMA Rx enable (DRxEN)
0 = DMA Rx disabled
1 = DMA Rx enabled
[8] DPLL enable (DPLLEN)
0 = Disable
1 = Enable; DPLL enters search mode for a locking edge in the incoming data stream.
[9] BRG enable (BRGEN)
0 = BRG counter is inbibited.
1 = BRG counter is enabled.
[10] Tx 4 word burst mode (Tx4WD)
0 = 1-word mode selected.
1 = 4-word mode selected.
[11] Rx 4 word burst mode (Rx4WD)
0 = 1-word mode selected.
1 = 4-word mode selected.
[13:12] Rx widget algnment (RxWA)
00 = No invalid byte
01 = 1 invalid byte
10 = 2 invalid byte
11 = 3 invalid byte
[14] DMA Tx stop or skip (DTxSTSK)
0 = DMA Tx skips when DMA not owner bit is set.
1 = DMA Tx stops when DMA not owner bit is set.
[15] DMA Rx stop or skip (DRxSTSK)
0 = DMA Rx skips when DMA not owner bit is set.
1 = DMA Rx stops when DMA not owner bit is set.
[16] DMA Rx memory address decrement (DRxMADEC)
0 = Address is incremented.
1 = Address is decremented.
[17] Tx flag idle (TxFLAG)
0 = Enter mark idle mode (a bit pattern of consecutive ones)
1 = Enter time fill mode (a bit pattern of consecutive opening (closing) flag, as in string
01111110 01111110......
Figure 8-14. HDLC Control Register (HCON)
8-33
HDLC CONTROLLERS
S3C4510B
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
A R T R T T T
R T T T D D D
R
x
W
A
R T B
R
x
D D D
P R T
T D D R T
x R T
T
x
u
t
x
x
x
x
x
x
x
x
x
x R R T
x
4
x R
4 G
x x
N N D D P A
E L S F
x
x
x
E
L
x
x
E x x R R
A
B
T
E
X
T
o O O
I
T R B
C O F L M S S
H O L A A T T
O P A G D S S
W W E
D D N
N N R R S S
S S
L E E
E N N
N
E C C S R M T
N R R C
C C O
N
B
G
E K K
C
[18] Tx single flag (TxSFLAG)
0 = Double flag mode (a closing & opening flags are used to separate frames)
1 = Single flag mode (only one flags are used to separate frames)
[19] Tx loop-back mode (TxLOOP)
0 = Normal operation.
1= The tramsmit data output is internally connected to the receiver data input for self
testing.
[20] Rx echo mode (RxECHO)
0 = Disable Tx auto-echo mode.
1 = Enable Rx DMA Tx block is reset.
[21] Tx abort extension (TxABTEXT)
0 = At least consecutive eigth 1s are transferred.
1 = At least 16 consecutive 1s are transferred.
[22] Tx abort (TxABT)
0 = Normal
1 = Enable (at least eight consecutive 1s are transmitted.)
[23] Tx preamble (TxPRMB)
0 = Transmit a mark idle is time fill bit pattern.
1 = Transmit the content of HPRMB
[24] Tx data terminal ready (TxDTR)
0 = nDTR goes high level.
1 = nDTR goes low level.
[25] Rx frame discontinue (TxDISCON)
0 = Normal
1 = Ignore the currently received frame
[26] Tx No CRC (TxNOCRC)
0 = Disable
1 = CRC is not appended by hardware.
[27] Rx No CRC (RxNOCR)
0 = Disable
1 = Receiver does not check CRC by hardware.
(CRC is treated as data in any case)
[28] Auto enable (AutoEN)
0 = Normal operation. The nCTS and nDCD become high, the transmitter sends mark
idle and receiver receives data.
1 = The nDCD and nCTS become high, RxFIFO, Rx block, TxFIFO, and Tx block are
cleared. The transmitter sends mark idle, and the receiver does not operate.
[31:29] Reserved
Figure 8-15. HDLC Control Register (HCON) (Continued)
8-34
S3C4510B
HDLC CONTROLLERS
HDLC STATUS REGISTER (HSTAT)
NOTE
Reading the HDLC status register is a non-destructive process. The method used to clear a High-level
status condition depends on the bit's function and operation mode (DMA or interrupt). For details, please
see the description of each status register.
Table 8-10. HSTATA and HSTATB Register
Registers
HSTATA
HSTATB
Offset
0x7008
0x8008
R/W
R/W
R/W
Description
Reset Value
0X00000000
0X00000000
HDLC Channel A Status Register
HDLC Channel B Status Register
SUMMARY
There are two kinds of bits in a status register.
1. TxFA, TxCTS, RxFA, RxDCD, RxFV, RxCRCE, RxNO, RxIERR, and RxOV bits are show each bit's
status. These bits are set or cleared automatically according to the each bit status.
2. All other bits are cleared by the CPU writing '1' to each bit.
8-35
HDLC CONTROLLERS
S3C4510B
Table 8-11. HSTAT Register Description
Description
Bit
Bit Name
Number
[3:0]
Rx remaining bytes
(RxRB)
(RxRB + 1) indicates how many data bytes are valid in a 1-word or 4-word
boundary when the receiver has received a complete frame. In 1-word
transfer mode, the RxRB value is either 0, 1, 2, or 3. In 4-word mode, it is
0, 1, ..., 14, or 15.
[4]
[5]
Tx frame complete
(TxFC)
This status bit is automatically set to '1' when the two conditions are met:
1) there is no data in the Tx FIFO, and 2) either an abort or a closing flag is
transmitted. You can clear this bit by writing '1' to this bit.
Tx FIFO available
(TxFA)
If this bit is '1', the data to be sent can be loaded into the HTxFIFO
register. In 1-word transfer mode, the TxFA status bit is set to '1' when the
first register of the HTxFIFO is empty.
In 4-word transfer mode, TxFA = '1' when the first four 32-bit registers of
the HTxFIFO are empty. The TxFA status condition is automatically
cleared when HTxFIFO is no longer available. During DMA Tx operation,
this bit is always ’0', so not generating interrupt.
[6]
Tx clear-to-send
(TxCTS)
The nCTS input is projected to this status bit. If the level at the nCTS input
pin is Low, this status bit is'1'. If nCTS input pin is High level, TxCTS is '0'.
This bit does not generate an interrupt.
[7]
[8]
Tx stored clear-to-send This bit is set to '1' each time a transition in nCTS input occurs. You can
(TxSCTS)
clear this bit by writing '1' to this bit.
Tx under-run (TxU)
When the transmitter runs out of data during a frame transmission, an
underrun occurs and the frame is automatically terminated by transmitting
an abort sequence. The underrun condition is indicated when TxU is '1'.
You can clear this bit by writing a '1' to this bit.
[9]
Rx FIFO available
(RxFA)
This status bit indicates when the data received can be read from the Rx
FIFO. When RxFA is '1', it indicates that data (other than an address or a
final data word) is available in the HRXFIFO. In 1-word transfer mode,
RxFA bit set to '1' when received data is available in the last FIFO register.
In 4-word transfer mode, it is set to '1' when the data received is available
in the last four 32-bit FIFO registers. Even if the data reside in FIFO for
only two words, when the Last bit is set, Rx FIFO is regarded as valid. (The
received data available condition is cleared automatically when the data
received is no longer available.) During DMA Rx operation, this bit is
always '0', so does not generate an interrupt.
[10]
Reserved
No applicable.
8-36
S3C4510B
HDLC CONTROLLERS
Table 8-11. HSTAT Register Description (Continued)
Bit Name Description
Bit
Number
[11]
Rx flag detected (RxFD) This bit is set to '1' when the last bit of the flag sequence is received. This
bit generates an interrupt if enabled. You can clear this bit by writing a
'1' to this bit.
[12]
[13]
[14]
[15]
Rx data carrier detected The DCD status bit mirrors the state of the nDCD input pin. If nDCD input
(RxDCD)
pin is low, this status bit is '1'. If nDCD input pin is High, it is '0'. This bit
does not generate an interrupt.
Rx stored data carrier
detected (RxSDCD)
This bit is set to '1' when a transition in nDCD input occurs, and can
generate interrupt, if enabled. You can clear this bit by writing a '1' to this
bit.
Rx frame valid (RxFV)
Rx idle (RxIDLE)
This bit signals frame's ending boundary to the CPU and also indicates that
no frame error occurred. It is set when the last data byte of a frame is
transferred into the last location of the Rx FIFO and is available to be read.
The RxIDLE status bit indicates that a minimum of 15 consecutive 1s have
been received. The event is stored in the status register and can be used
to trigger a receiver interrupt. The RxIDLE bit continues to reflect the
inactive idle condition until a '0' is received. You can clear this bit by
writing a '1' to this bit.
[16]
Rx abort (RxABT)
The RxABT status bit is set to '1' when seven or more consecutive 1s
(abort sequence) have been received. When an abort is received in an 'in-
frame' condition, the event is stored in the status register triggering an
interrupt request. You can clear this bit by writing a '1' to this bit.
[17]
[18]
[19]
Rx CRC error
(RxCRCE)
The RxCRCE status bit is set a frame is completed with a CRC error.
Rx non-octet align
(RxNO)
The RxNO bit is set to '1', if received data is non-octet aligned frame.
Rx overrun (RxOV)
The RxOV status bit is set to '1', if the data received is transferred into the
HRXFIFO when it is full, resulting in a loss of data. Continued overruns
destroy data in the first FIFO register.
[20]
DMA Rx memory
overflow (RxMOV)
This bit is set when there is no more buffer during receiving data. If this bit
is set, DRxEN bit is cleared. You can clear this bit by writing '1' to this bit.
[21]
[22]
Reserved.
Not applicable.
DMA Tx abort
(DTxABT)
This bit is set to '1' when abort signal is sent due to the Tx underrun or CTS
lost occurred. If this bit is set, DTxEN(in HCON) bit cleared. You can clear
this bit by writing '1' to this bit.
8-37
HDLC CONTROLLERS
S3C4510B
Table 8-11. HSTAT Register Description (Continued)
Bit Name Description
Bit
Number
[23]
Rx internal error
(RxIERR)
This bit is set to '1' when received frame will be detected error possibility
due to the receive clock is unstable.
[24]
DMA Rx frame done
every received frame
(DRxFD)
This bit is set when a DMA Rx operation has successfully operated a frame
to memory from HRXFIFO, and when the last byte of a frame has been
written to memory. This bit generate interrupt when set to '1' to know a
frame is received. You can clear this bit by writing '1' to this bit.
[25]
[26]
[27]
[28]
[29]
DMA Rx null list
(DRxNL)
If this bit is set, the DMA Rx buffer descriptor pointer has a null address. In
this case, DMA Rx is disabled and the data transfer from the Rx FIFO to
buffer memory is discontinued. So the HRXFIFO is cleared. You can clear
this bit by writing '1' to this bit.
DMA Rx not owner
(DRxNO)
This bit is set, when DMA is not owner of the current buffer descriptor, and
DRxSTSK bit was set. In this case, DMA Rx is disabled and can generate
interrupt, if enabled. If DRxSTSK bit is zero, this bit is always zero. You
can clear this bit by writing '1' to this bit.
DMA Tx frame done
(DTxFD)
In case of MFF bit is '0' (default), when DNA Tx operation has successfully
transferred rest byte of frame from Tx FIFO to destination, this bit will be
set to ’1’. But if MFF is set to ’1’, transceiver will keep sending the data
until there is no data transfer from memory to TxFIFO.
DMA Tx null list
(DTxNL)
If this bit is set '1', the DMA Tx buffer descriptor pointer has a null address.
In this case, DMA Tx is disabled and the data to be transferred
discontinued from the buffer memory to Tx FIFO. You can clear this bit by
writing '1' to this bit.
DMA Tx not owner
(DTxNO)
This bit is set, when DMA is not owner of the current buffer descriptor, and
DTxSTSK bit was set. In this case, DMA Tx disabled and can generate
interrupt, if enabled. If DTxSTSK bit is zero, this bit is always zero. You
can clear this bit by writing '1' to this bit.
[30]
[31]
DPLL one clock missing When operating in FM/Manchester mode, the DPLL sets this bit to '1' if it
(DPLLOM)
does not detect an edge in its first attempt. You can clear this bit by writing
a '1' to this bit.
DPLL two clock missing When it is operating in the FM/Manchester mode, the DPLL sets this bit to
(DPLLTM)
'1' if it does not detect an edge in two successive attempts. At the same
time the DPLL enters Search mode. In NRZ/NRZI mode, and while the
DPLL is disabled, this bit is always '0'. You can clear this bit by writing a '1'
to this bit.
8-38
S3C4510B
HDLC CONTROLLERS
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3 2 1 0
D D D D D D D D R D
R R R R R R R R R R
R
x
F
A
T
x
F
A
T T T
T
x
F
C
R
x
R
B
P P T T T R R R x
T
x
x
x
x
x
x
x
I
x x x x
x
x x
L L
x
x
x
x
x
x
I
M O N C A
F S D F
U S C
C T
T S
S
L L N N F N N F E A
T O O L D O L D R B
O V O R B D V D C D
V
C T L
C D
D
M M
R T
E
E
[3:0] Rx remaining bytes (RxRB)
At 1-word boundary:
At 4-word boundary:
0000 = Valid data byte is 1
0001 = Valid data byte is 2
0010 = Valid data byte is 3
0011 = Valid data byte is 4
0000 = Valid data byte is 1
.
.
1111 = Valid data byte is 16
[4] Tx frame complete (TxFC)
0 = Normal operation
1 = Automatically set; if two conditions are met:
1) Tx FIFO is empty.
2) An abort or a closing flag is transmitted.
[5] Tx FIFO available (TxFA)
0 = Tx FIFO is not available.
1 = Tx FIFO is available. (that is, the data to be transmitted can now be
loaded into the Tx FIFO.)
[6] Tx clear-to send (TxCTS)
0 = Level at the nCTS input pin is High.
1 = Level at the nCTS input pin is Low.
[7] Tx stored clear-to-send (TxSCTS)
0 = Normal operation
1 = A transition occured at the nCTS input. (This transition can be used to
trigger an interrupt.)
[8] Tx underrun (TxU)
0 = Normal operation
1 = The transmitter ran out of data during transmission.
[9] Rx FIFO available (RxFA)
0 = Normal operation
1 = Data is available in the RxFIFO.
[10] Reserved
[11] Rx flag detected (RxFD)
0 = Normal operation
1 = This bit is set, when the last bit of the flag sequence is received.
[12] Rx data-carrier-detected (RxDCD)
0 = nDCD input pin is High
1 = nDCD input pin is Low
[13] Rx stored data-carrier-detected (RxSDCD)
0 = Normal operation
1 = When a transition of the nDCD input occurs, this bit is set.
[14] Rx frame valid (RxFV)
0 = Normal operation
1 = The last data byte if a frame is transgerred into the last location of RxFIFO.
[15] Rx idle (RxIDLE)
0 = Normal operation
1 = A minimum 15 consecutive 1s have been reveived.
Figure 8-16. HDLC Status Register
8-39
HDLC CONTROLLERS
S3C4510B
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
D D D D D D D D R D
R R R R R R R R R R
R
x
F
A
T
x
F
T T T
T
x
F
R
x
R
B
P P T T T R R R x
L L
T
x
x
x
x
x
x
x
I
x x x x
x
x x
x
x
x
x
x
x
I
M O N C A
F S D F
U S C
C T
T S
S
L L N N F N N F E A
T O O L D O L D R B
O V O R B D V D C D
A C
V
C T L
C D
D
M M
R T
E
E
[16] Rx abort (RxABT)
0= Normal operation
1 = Seven or more consecutive 1s have been received, in-frame condition.
[17] Rx CRC error (RxCRCE)
0 = Normal operation
1 = A frame Rx operation is completed with a CRC error.
[18] Rx non-octet align (RxNO)
0 = Received frame is octet.
1 = Received frame is not octet.
[19] Rx overrun (RxOV)
0 = Normal operation
1 = Received data is transferred into the RxFIFO when it is full.
[20] Rx memory overflow (RxMOV)
0 = Normal operation
1 = Indicates memory overflow when Rx buffer descriptor next pointer has null address.
[21] Reserved
[22] DMA Tx abort (DTxABT)
0 = Normal operation
1 = Abort signal is sended and DMA Tx enable bit is cleared.
[23] Rx internal error (RxIERR)
0 = Normal operation
1 = Received frame is not stable due to receive clock is unstable.
[24] DMA Rx frame done every received frame (DRxFD)
0 = Normal operation
1 = DMA Rx operation has successfully transferred a frame from RxFIFO to buffer memory.
[25] DMA Rx null list (DRxNL)
0 = Normal operation
1 = DMA Rx buffer descriptor pointer has a null address.
[26] DMA Rx not owner (DRxNO)
0 = DMA has the ownership.
1 = CPU has the ownership.
[27] DMA Tx frame done (DTxFD)
0 = Normal operation
1 = DMA Tx operation has successfully transferred a frame from memory to TxFIFO.
[28] DMA Tx null list (DTxNL)
0 = Normal operation
1 = DMA Tx buffer descriptor pointer has a null address.
[29] DMA Tx not owner (DTxNO)
0 = DMA has the ownership.
1 = CPU has the ownership.
[30] DPLL one clock missing (DPLLOM)
0 = Normal operation
1 = Set in FM/Machester mode when DPLL does not detect an edge on the first entry.
[31] DPLL two clock missing (DPLLTM)
0 = Normal operation
1 = DPLL was not detected on two consecutive edges and search mode was entered.
Figure 8-17. HDLC Status Register (Continued)
8-40
S3C4510B
HDLC CONTROLLERS
HDLC INTERRUPT ENABLE REGISTER (HINTEN)
Table 8-12. HINTENA and HINTENB Register
Registers
HINTENA
HINTENB
Offset
0x700c
0x800c
R/W
R/W
R/W
Description
Reset Value
0X00000000
0X00000000
HDLC Interrupt Enable Register
HDLC Interrupt Enable Register
Table 8-13. HINTEN Register Description
Description
Bit
Bit Name
Number
[3:0]
[4]
Reserved
TxFCIE
–
Tx frame complete interrupt enable
Tx FIFO available to write interrupt enable
–
[5]
TxFAIE
[6]
Reserved
TxSCTSIE
TxUIE
[7]
CTS transition has occurred interrupt enable
Tx under-run has occurred interrupt enable
Rx FIFO available to read interrupt enable
–
[8]
[9]
RxFAIE
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
[28]
[29]
[30]
[31]
Reserved
RxFDIE
Rx flag detected interrupt enable
–
Reserved
RxSDCDIE
RxFVIE
DCD transition interrupt enable
Rx frame valid interrupt enable
Idle detected interrupt enable
Abort detected interrupt enable
CRC error frame interrupt enable
Non-octet aligned frame interrupt enable
Rx overrun interrupt enable
Rx memory overflow interrupt enable
–
RxIDLEIE
RxABTIE
RxCRCEIE
RxNOIE
RxOVIE
RxMOVIE
Reserved
DTxABTIE
RxIERRIE
DRxFDIE
DRxNLIE
DRxNOIE
DTxFDIE
DTxNLIE
DTxNOIE
DPLLOMIE
DPLLTMIE
DMA Tx abort interrupt enable
Rx internal error interrupt enable
DMA Rx frame done interrupt enable
DMA Rx null list interrupt enable
DMA Rx not owner interrupt enable
DMA Tx frame done every transmitted frame interrupt enable
DMA Tx null list interrupt enable
DMA Tx not owner interrupt enable
DPLL one clock missing interrupt enable
DPLL two clocks missing interrupt enable
8-41
HDLC CONTROLLERS
S3C4510B
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3 2 1 0
D D D D D D D D R D
R R R R R R R R
R
x
F
D
I
R
x
F
A
I
T
x
F
T T
T
x
F
P P T T T R R R x
L L
T
x
x
x
x
x
x
x
I
x x
x
x
x
x
x
x
x
x
I
M O N C A
F S
U S
L L N N F N N F E A
T O O L D O L D R B
O V O R B D V D
A C
I
C
V
I
I
I
C T L
I
C
I
E T
I
M M
I
I
I
I
I
I
R T
E E E
I
E E D
E
E
E E
S
I
E
I
I
E E E E E E
I
I
E
I
E
I
I
E E
E E
E
E
E
[3:0] Reserved
[18] Non-dctet aligned frame interrupt enable
(RxNOIE)
[4] Tx frame complete interrupt enable
(TxFCIE)
[19] Rx overrun interrupt enable (RxOVIE)
[5] Tx FIFO available to write interrupt
enable (TxFAIE)
[20] Rx memory overflow interrupt enable
(RxMOVIE)
[6] Reserved
[21] Reserved
[7] CTS transition has occurred interrupt
enable (TxSCTIE)
[22] DMA Tx abort interrupt enable
(DTxABTIE)
[8] Transmit underrun has occured
interrupt enable (TxUIE)
[23] Rx internal error interrupt enable
(RxIERRIEN)
[9] RxFIFO available to read interrupt
enable (RxFAIE)
[24] DMA Rx frame done every received frame
interrupt enable (DRxFDIE)
[10] Reserved
[25] DMA Rx null list interrupt enable
(DRxNLIE)
[11] Flag detected interrupt enable
(RxFDIE)
[26] DMA Rx not owner interrupt enable
(DRxNOIE)
[12] Reserved
[27] DMA Tx frame done every received frame
interrupt enable (DTxFDIE)
[13] DCD transition interrupt enable
(RxSDCDIE)
[28] DMA Tx null list interrupt enable
(DTxNLIE)
[14] Valid frame interruopt enable (RxFVIE)
[15] Idle detected interruot enable
(RxIDLEIE)
[29] DMA Tx not owner interrupt enable
(DTxNOIE)
[16] Abort detected interrupt enable
(RxABTIE)
[30] DPLL one missing interrupt enable
(DPLLOMIE)
[17] CRC error frame interrupt enable
(RxCRCEIE)
[31] DPLL two missing interrupt enable
(DPLLTMIE)
Figure 8-18. HDLC Interrupt Enable Register
8-42
S3C4510B
HDLC CONTROLLERS
HDLC TX FIFO (HTXFIFO)
The Tx FIFO consists of eight 32-bit registers that are used for buffer storage of data to be transmitted. Data is
always transferred from a full register to an empty adjacent register. The Tx FIFO can be addressed at two
different register addresses: the 'frame continue' address and the 'frame terminate' address.
Each register has four pointers, data valid pointer bit (4 bits), last pointer bit, NoCRC pointer bit, Preamble
pointer bit. The data valid pointer bit indicates whether each byte is valid or not. The last byte pointer bit indicates
whether the frame to be sent has the frame last byte or not. The NoCRC pointer bit determines whether the CRC
data is to be appended or not by hardware.
When a valid data byte is written to the 'frame continue' address, the data valid pointer is set, but the last byte
pointer is not set. When a valid data byte is written to the 'frame terminate' address, the data valid pointer and
last byte pointer are set together. To reset these pointers, you write a '1' to either the TxABT bit or the TxRS bit in
the HCON register.
In DMA mode, when the DMA controller writes data to the HTxFIFO, Tx buffer descriptor Buffer Length field
value must be pre-set. However, if the Last bit is set in buffer descriptor, the last byte pointer in HTxFIFO is also
set. This means the last byte of the frame is in HTxFIFO. If the transmitted frame is longer than the Buffer
Length field value, the last byte pointer will not be set, and the next buffer descriptor having the last byte pointer
bit will be used.
The pointers continue shifting through the FIFO. When the transmitter detects a positive transition in the data
valid pointer at the last location of the FIFO, it initiates a frame with an opening flag. When it detects a negative
transition in the last byte pointer at the last location of the FIFO, it closes the frame, appending the CRC and a
closing flag follows.
The status of the Tx FIFO is indicated by the transmitter FIFO register available (TxFA) status bit. When TxFA =
'1', the Tx FIFO is available for loading data and data can be loaded into it. (This function is controlled by the
Tx4WD bit.) The HTxFIFO is reset by writing a '1' to the Tx reset, or the TxABT bit or by the nRESET. During a
reset operation, the TxFA status bit is suppressed and data loading is inhibited.
TxFIFO
8-bit 8-bit
Data Valid (4-bit)
Last (1-bit)
NoCRC
Preamble
8-bit
8-bit
8
Tx Data
Figure 8-19. HDLC Tx FIFO Function Diagram
8-43
HDLC CONTROLLERS
S3C4510B
HDLC RX FIFO (HRXFIFO)
The Rx FIFO consists of eight 32-bit registers that are used for the buffer storage of the data received. Data
bytes are always transferred from a full register to an adjacent empty register. Each register has pointer bits that
indicate the frame status. When these pointers appear at the last 1-word or 4-word FIFO location, they update the
LAST bit(indicating the last of a frame), the OVERRUN bit, the CRC error bit, or Non-octet aligned bit.
The HRXFIFO data available (RxFA) status bits indicate the current state of the HRXFIFO. When the HRXFIFO
data status bit is '1', the HRXFIFO is ready to be read. The HRXFIFO data status is controlled by the 4-word or 1-
word transfer selection bit (Rx4WD). When an overrun occurs, the overrun frame of the HRXFIFO is no longer
valid.
An 'in frame' abort or a High level on nDCD input with the AutoEN bit in HCON is set to '1', the frame is cleared in
the HRXFIFO. (The last byte of the previous frame, which is separated by the frame boundary pointer, is
retained). Data in HRXFIFO should be read by word size.
The HRXFIFO is cleared by the Rx reset bit set to '1', an abort signal received, or nRESET.
RxFIFO
8-bit 8-bit
Data Valid
Last
OV
CRCE
NO
8-bit
8-bit
Rx Data
Figure 8-20. HDLC Rx FIFO Function Diagram
8-44
S3C4510B
HDLC CONTROLLERS
HDLC BRG TIME CONSTANT REGISTERS (HBRGTC)
Table 8-14. HBRGTCA and HBRGTCB Register
Registers
HBRGTCA
HBRGTCB
Offset
0x701c
0x801c
R/W
R/W
R/W
Description
Reset Value
0x00000000
0x00000000
HDLC BRG Time Constant Register
HDLC BRG Time Constant Register
The HDLC BRG time constant register value can be changed at any time, but the new value does not take effect
until the next time the constant is loaded into the down counter. No attempt is made to synchronize the loading of
the time constant into HBRGTC while the clock is driving the down counter. For this reason, you should first
disable the baud rate generator before loading the new time constant into the HBRGTC register.
The formula for determining the appropriate time constant for a given baud rate is shown below. The desired rate
is shown in bits per second. This formula shows how the counter decrements from N down to zero-plus-one
cycles for reloading the time constant. This value is then fed to a toggle flip-flop to generate the square wave
output.
BRGOUT1 = (MCLK2 or RXC)/(CNT0 + 1)/(16CNT1
BRGOUT2 = BRGOUT1/(1 or 16 or 32 according to CNT2 value of the HBRGTC)
)
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8 7 6 5 4 3 2 1 0
CNT1 CNT2
CNT0
[1:0] Time constant value for CNT2
00 = divide by 1
01 = adivide by 16
10 = divide by 32
[3:2] Time constant value for CNT1
00 = divide by 1
01 = divide by 16
[15:4] Time constant value for CNT0
Figure 8-21. HDLC BRG Time Constant Register
8-45
HDLC CONTROLLERS
S3C4510B
HDLC PREAMBLE CONSTANT REGISTER (HPRMB)
The HPRMB register is used to meet the DPLL requirements for phase-locking. The preamble pattern is
transmitted as many Tx preamble length bit values in HMODE[10:8] when the Tx preamble bit (TxPRMB) is '1',
and then the Tx preamble bit is cleared automatically. The opening flag follows this preamble pattern, and the
data will be transmitted.
Table 8-15. HPRMBA and HPRMBB Register
Registers
HPRMBA
HPRMBB
Offset
0x7020
0x8020
R/W
R/W
R/W
Description
Reset Value
0x00000000
0x00000000
HDLC Preamble Constant Register
HDLC Preamble Constant Register
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8 7 6 5 4 3 2 1 0
Preamble Pattern
[7:0] Preamble Pattern
Figure 8-22. HDLC Preamble Constant Register
The reference for the preamble pattern of each data mode is as follows:
Table 8-16. Preamble Reference Pattern
Data Mode
NRZ
Preamble Pattern
AA
00
NRZI
FM0
FF
00
FM1
MANCHESTER
AA
8-46
S3C4510B
HDLC CONTROLLERS
HDLC STATION ADDRESS REGISTERS (HSADR0–3) AND HMASK REGISTER
Each HDLC controller has five 32-bit registers for address recognition: four station address registers and one
mask register. Generally, the HDLC controller reads the address of the frame from the receiver, to check it
against the four station address values, and then masks the result with the user-defined HMASK register. A "1" in
the HMASK register represents a bit position for which an address comparison should occur. A "0" represents a
masked bit position. If you check the address up to four bytes, the HMASK register value should be 0xffffffff.
Dependent on the HMASK register value, the frame's address is compared. If the address is not matched, this
frame is discarded.
Table 8-17. HSADR and HMASK Register
Registers
HSADR0A
HSADR1A
HSADR2A
HSADR3A
HMASKA
HSADR0B
HSADR1B
HSADR2B
HSADR3B
HMASKB
Offset
0x7024
0x7028
0x702c
0x7030
0x7034
0x8024
0x8028
0x802c
0x8030
0x8034
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Description
HDLC station address 0
HDLC station address 1
HDLC station address 2
HDLC station address 3
HDLC address mask register
HDLC station address 0
HDLC station address 1
HDLC station address 2
HDLC station address 3
HDLC address mask register
Reset Value
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
HMASK
0xFFFFFFFF
HMASK
HSADR0
HSADR1
HSADR2
HSADR3
0xFF0000 00
HSADR0
HSADR1
HSADR2
HSADR3
0xABCDEFGH
0xFFFFFFFF
0xABCDEFGH
0xABCDEFGH
0x55XXXX XX
0x55XXXX XX
0x55XXXX XX
0x55XXXX XX
NOTE:
Recognize one 32-bit address
NOTE:
Recognize a single 8-bit address
and the 32-bit broadcast address
Figure 8-23. Address Recognition
8-47
HDLC CONTROLLERS
S3C4510B
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
First byte Second byte Third byte
8
7
6
5
4
3
2
1
0
Fourth byte
Station address byte register and MASK register
[31:24] First address byte
[23:16] Second address byte
[15:8] Third address byte
[7:0] Fourth address byte
Figure 8-24. HDLC Station Address and HMASK Register
DMA TX BUFFER DESCRIPTOR POINTER REGISTER
The DMA transmit buffer descriptor pointer register contains the address of the Tx buffer data pointer on the data
to be sent. During a DMA operation, the buffer descriptor pointer is updated by the next buffer data pointer.
Table 8-18. DMA Tx Buffer Descriptor Pointer Registers
Registers
Offset
0x7038
0x8038
R/W
R/W
R/W
Description
Reset Value
0xFFFFFFFF
0xFFFFFFFF
HDMATXPTRA
HDMATXPTRB
DMA Tx Buffer Descriptor Pointer
DMA Tx Buffer Descriptor Pointer
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8 7 6 5 4 3 2 1 0
DMA Tx Buffer Descriptor Pointer
[25:0] DMA Tx Buffer Descriptor Pointer
Figure 8-25. DMA Tx Buffer Descriptor Pointer
8-48
S3C4510B
HDLC CONTROLLERS
DMA RX BUFFER DESCRIPTOR POINTER REGISTER
The DMA receive buffer descriptor pointer register contains the address of the Rx buffer data pointer on the data
to be received. During a DMA operation, the buffer descriptor pointer is updated by the next buffer data pointer.
Table 8-19. DMA Rx Buffer Descriptor Pointer Registers
Registers
Offset
0x703c
0x803c
R/W
R/W
R/W
Description
Reset Value
0xFFFFFFFF
0xFFFFFFFF
HDMARXPTRA
HDMARXPTRB
DMA Rx Buffer Descriptor Pointer
DMA Rx Buffer Descriptor Pointer
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8 7 6 5 4 3 2 1 0
DMA Rx Buffer Descriptor Pointer
[25:0] DMA Rx Buffer Descriptor Pointer
Figure 8-26. DMA Rx Buffer Descriptor Pointer
MAXIMUM FRAME LENGTH REGISTER
The HDLC controller checks the length of an incoming frame against the user-defined value in DMA mode. If the
frame received exceeds this register value, the frame is discarded, and FLV(Frame Length Violated) bit is set in
the buffer descriptor belonging to that frame.
Table 8-20. HDMATXCNT and HDMARXCNT Registers
Registers
HMFLRA
HMFLRB
Offset
0x7040
0x8040
R/W
R/W
R/W
Description
Maximum Frame Length
Maximum Frame Length
Reset Value
0xXXXX0000
0xXXXX0000
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8 7 6 5 4 3 2 1 0
Maximum Frame Length
[15:0] Maximum Frame Length
Figure 8-27. Maximum Frame Length Register
8-49
HDLC CONTROLLERS
S3C4510B
RECEIVE BUFFER SIZE REGISTER
The Rx buffer size register contains the 16-bit user-defined value. This user-defined count value determines the
buffer size for one Buffer Descriptor. If incoming HDLC frame is longer than the Rx buffer size register value, the
next buffer descriptor having the Rx buffer size value will be used.
Table 8-21. DMA Rx Buffer Size Register
Registers
HRBSRA
HRBSRB
Offset
0x7044
0x8044
R/W
R/W
R/W
Description
Receive Buffer Size Register
Receive Buffer Size Register
Reset Value
0xXXXX0000
0xXXXX0000
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8 7 6 5 4 3 2 1 0
Receive Buffer Size
[15:0] Receive Buffer Size Register
Figure 8-28. DMA Receive Buffer Size Register
8-50
S3C4510B
DMA CONTROLLER
9
DMA CONTROLLER
OVERVIEW
The S3C4510B has a two-channel general DMA controller, called the GDMA. The two-channel GDMA performs
the following data transfers without CPU intervention:
— Memory-to-memory (memory to/from memory)
— UART-to-memory (serial port to/from memory)
The on-chip GDMA can be started by software and/or by an external DMA request (nXDREQ). Software can also
be used to restart a GDMA operation after it has been stopped.
The CPU can recognize when a GDMA operation has been completed by software polling and/or when it receives
an appropriate internally generated GDMA interrupt. The S3C4510B GDMA controller can increment or
decrement source or destination addresses and conduct 8-bit (byte), 16-bit (half-word), or 32-bit (word) data
transfers.
System BUS
Mode Selection
GDMA Channel 0
nXDREQ 0
UART0
nDREQ
UART1
nDACK
nXDACK 0
GDMA
Port 14 Data
IOPCON [27:26]
GDMA Channel 1
nDREQ
nDACK
nXDREQ 1
nXDACK 1
GDMA
Mode Selection
Port 15 Data IOPCON [29:28]
Figure 9-1. GDMA Controller Block Diagram
9-1
DMA CONTROLLER
S3C4510B
GDMA SPECIAL REGISTERS
Table 9-1. GDMA Special Registers Overview
Registers
GDMACON0
GDMACON1
GDMASRC0
GDMADST0
GDMASRC1
GDMADST1
GDMACNT0
GDMACNT1
Offset
0xB000
0xC000
0xB004
0xB008
0xC004
0xC008
0xB00C
0xC00C
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Description
Reset Value
0´ 00000000
0´ 00000000
Undefined
Undefined
Undefined
Undefined
Undefined
Undefined
GDMA controller channel 0 control register
GDMA controller channel 1 control register
GDMA channel 0 source address register
GDMA channel 0 destination address register
GDMA channel 1 source address register
GDMA channel 1 destination address register
GDMA channel 0 transfer count register
GDMA channel 1 transfer count register
GDMA CONTROL REGISTERS
Table 9-2. GDMACON0 and GDMACON1 Registers
Registers
GDMACON0
GDMACON1
Offset
0xB000
0xC000
R/W
R/W
R/W
Description
Reset Value
0´ 00000000
0´ 00000000
GDMA controller channel 0 control register
GDMA controller channel 1 control register
Table 9-3. GDMA Control Register Description
Bit Name Reset Value
Bit Number
[0]
Run enable/disable
Setting this bit to "1", starts a DMA operation. To stop DMA, you
must clear this bit to "0". You can use the GMA run bit control
address (GDMACON offset address + 0x20) to manipulate this bit.
By using the run bit control address, other GDMA control register
values are not affected.
[1]
Busy status
When DMA starts, this read-only status bit is automatically set to
"1". When it is "0", DMA is idle.
[3:2]
GDMA mode selection
Four sources can initiate a DMA operation: 1) software (memory-
to-memory), 2) an external DMA request (nXDREQ), 3) the UART0
block, and 4) the UART1 block. The mode selection setting
determines which source can initiate a DMA operation at any given
time.
[4]
[5]
Destination address
direction
This bit controls whether the destination address will be
decremented ("1") or incremented ("0") during a DMA operation.
Source address direction This bit controls whether the source address will be decremented
("1") or incremented ("0") during a DMA operation.
9-2
S3C4510B
DMA CONTROLLER
Table 9-3. GDMA Control Register Description (Continued)
Bit Number
Bit Name
Reset Value
Destination address fix
This bit determines whether or not the destination address will be
changed during a DMA operation. You use this feature when
transferring data from multiple sources to a single destination.
[6]
[7]
[8]
Source address fix
This bit determines whether or not the source address will be
changed during a DMA operation. You use this feature when
transferring data from a single source to multiple destinations.
Stop interrupt enable
To start/stop a DMA operation, you set/clear the run enable bit. If
the stop interrupt enable bit is "1" when DMA starts, a stop interrupt
is generated when DMA operation stops. If this bit is "0", the stop
interrupt is not generated.
Four-data burst enable
If this bit is set to one, GDMA operates under 4-data burst mode.
under the 4-data burst mode, 4 consecutive source addresses are
read and then are written to the consecutive destination addresses.
If 4-data burst mode is set to one, "transfer count register" should
be set carefully because the 4-data burst move is executed during
decreasing of the transfer count. The 4-data burst mode can be
used only when GMDA mode is software or external DMA request
mode.
[9]
Peripheral direction
Single/Block mode
This bit is used to specify the direction of a DMA operation when
the mode bits [3:2] are set to '10' (UART0 from/to memory) or '11'
(UART1 from/to memory). If this bit is "1", DMA operates in the
memory-to-peripheral direction (e.g., to the parallel port or UART).
When it is "0", DMA operates in the peripheral-to-memory
direction.
[10]
[11]
This bit determines the number of external DMA requests
(nXDREQs) that are required for a DMA operation. In Single mode,
when [11] = "0", the S3C4510B requires an external DMA request
for every DMA operation.
In Block mode, when [11] = "1", the S3C4510B requires only one
external DMA request during the entire DMA operation. An entire
DMA operation is defined as the operation of DMA until the counter
value is zero.
NOTE: You should not use block mode together with demand
mode, or single mode in conjunction with continuous
mode.
Transfer width
These bits determine the transfer data width to be one byte, one
half-word, or one word. If you select a byte transfer operation, the
source/destination address will be incremented or decremented by
one with each transfer. Each half-word transfer increments or
decrements the address by two, and each word transfer by four.
[13:12]
[14]
Continuous mode
This bit lets the DMA controller hold the system bus until the DMA
transfer count value is zero. You must therefore manipulate this bit
carefully so that DMA transfer operations do not exceed a
acceptable time interval (as, for example, in a DRAM refresh
operation).
NOTE: You can use continuous mode together with a software
request mode.
9-3
DMA CONTROLLER
Bit Number
S3C4510B
Table 9-3. GDMA Control Register Description (Continued)
Bit Name Reset Value
Demand mode
[15]
Setting this bit speeds up external DMA operations. When [15]="1",
the DMA transfers data when the external DMA request signal
(nXDREQ) is active. The amount of data transferred depends on
how long nXDREQ is active. When nXDREQ is active and DMA
gets the bus in Demand mode, DMA holds the system bus until the
nXDREQ signal becomes non-active. Therefore, the period of the
active nXDREQ signal should be carefully timed so that the entire
operation does not exceed an acceptable interval (as, for example,
in a DRAM refresh operation).
NOTE: In demand mode, you must clear the single/block and
continuous mode control bits to "0".
NOTE: To ensure the reliability of DMA operations, the GDMA control register bits must be configured independently and
carefully.
9-4
S3C4510B
DMA CONTROLLER
31
16 15 14 13 12 11 10 9
8
7
6
5
4 3
2
1
0
M
O
D
E
D C
M N
T
W
S
T
F
S S D S D
A A
B R
S E
B D B
I
F F
[0] Run enable (RE)
0 = Disable DMA operation
1 = Enable DMA operation
1 = DMA is active
[1] Busy status (BS)
0 = DMA is idle
[3:2] Mode selection (MODE)
00 = Software mode (memory to memory)
01 = External EXTDREQ mode (for external devices)
10 = UART0 block
11 = UART1 block
[4:] Destination address direction (DA)
0 = Increase source address 1 = Decrease source address
[5] Source address direction (SA)
0 = Increase source address 1 = Decrease source address
[6] Destination address fix (DF)
0 = Increase/decrease destination address
1 = Do not change destination address (fix)
[7] Source address fix (SF)
0 = Increase/decrease source address
1 = Do not change source address (fix)
[8] Stop interrupt enable (SI)
0 = Do not generate a stop interrupt when DMA stops
1 = Generate a stop interrupt when DMA stops
[9] Four-data burst enable (FB)
0 = Disable 4-data burst mode
1 = Enable 4-data burst mode
[10] Transfer direction (for UART0/UART1 only) (TD)
0 = UART0/UART1 to memory 1 = Memory to UART0/UART1
[11] Single/block mode (SB)
0 = One nXDREQ initiates a single DMA operation
1 = One nXDREQ initiates a whole DMA operation
[13:12] Transfer width (TW)
00 = Byte (8 bits)
10 = Word (32 bits)
01 = Half-word (16 bits)
11 = No use
[14] Continuous mode (CN)
0 = Normal operation
1 = Hold system bus until the whole DMA operation stops
[15] Demand mode (DM)
0 = Normal external DMA mode
1 = Demand mode
Figure 9-2. GDMA Control Register
9-5
DMA CONTROLLER
S3C4510B
GDMA SOURCE/DESTINATION ADDRESS REGISTERS
The GDMA source/destination address registers contain the 26-bit source/destination addresses for GDMA
channels 0 and 1. Depending on the settings you make to the GDMA control register (GDMACON), the source or
destination addresses will either remain the same, or they will be incremented or decremented.
Table 9-4. GDAMSRC0/1 and GDMADST0/1 Registers
Registers
GDMASRC0
GDMADST0
GDMASRC1
GDMADST1
Offset
0xB004
0xB008
0xC004
0xC008
R/W
R/W
R/W
R/W
R/W
Description
Reset Value
Undefined
Undefined
Undefined
Undefined
GDMA channel 0 source address register
GDMA channel 0 destination address register
GDMA channel 1 source address register
GDMA channel 1 destination address register
31
26 25
0
Source/Destination Address
[25:0] Source/destination address
Figure 9-3. GDMA Source/Destination Address Register
9-6
S3C4510B
DMA CONTROLLER
DMA TRANSFER COUNT REGISTERS
The DMA transfer count registers contain the 24-bit current count value of the number of DMA transfers
completed for GDMA channels 0 and 1.
The count value is always decremented by one for each completed DMA operation, regardless of the GDMA data
transfer width or four-data burst mode.
NOTE
At the 4-data burst mode, actual transfer data size will be "Transfer Count x4."
Table 9-5. GDMACNT0/1 Registers
Registers
GDMACNT0
GDMACNT1
Offset
0xB00C
0xC00C
R/W
R/W
R/W
Description
Reset Value
Undefined
Undefined
GDMA channel 0 transfer count register
GDMA channel 1 transfer count register
31
24 23
0
Transfer Count
[23:0] Transfer count
Figure 9-4. DMA Transfer Count Register
9-7
DMA CONTROLLER
S3C4510B
GDMA FUNCTION DESCRIPTION
The following sections provide a functional description of the GDMA controller operations.
GDMA TRANSFERS
The GDMA transfers data directly between a requester and a target. The requester and target are memory,UART
or external devices. An external device requests GDMA service by activating nXDREQ signal. A channel is
programmed by writing to registers which contain requester address, target address, the amount of data, and
other control contents. UART, external I/O, or Software(memory) can request GDMA service. UART is internally
connected to the GDMA.
STARTING/ENDING GDMA TRANSFERS
GDMA starts to transfer data after the GDMA receives service request from nXDREQ signal, UART, or Software.
When the entire buffer of data has been transferred, the GDMA becomes idle. If you want to preform another
buffer transfer, the GDMA must be reprogrammed. Although the same buffer transfer wii be preformed again, the
GDMA must be reprogrammed.
DATA TRANSFER MODES
Single Mode
A GDMA request (nXDREQ or an internal request) causes one byte, one half-word, or one word to be transmitted
if 4-data burst mode is disable state, or four times of transfer width if 4-data burst mode is enable state. Single
mode requires a GDMA request for each data transfer. The nXDREQ signal can be de-asserted after checking
that nXDACK has been asserted.
nXDREQ
nXDACK
RD/WR Cycle
Figure 9-5. External DMA Requests (Single Mode)
9-8
S3C4510B
DMA CONTROLLER
Block Mode
The assertion of only one GDMA request (nXDREQ or an internal request) causes all of the data, as specified by
the control register settings, to be transmitted in a single operation. The GDMA transfer is completed when the
transfer counter value reaches zero. The nXDREQ signal can be de-asserted after checking that nXDACK has
been asserted.
nXDREQ
nXDACK
RD/WR Cycle
Figure 9-6. External DMA Requests (Block Mode)
Demand Mode
In demand mode, the GDMA continues transferring data as long as the GDMA request input (nXDREQ) is held
active.
nXDREQ
nXDACK
RD/WR Cycle
Figure 9-7. External DMA Requests (Demand Mode)
9-9
DMA CONTROLLER
S3C4510B
DMA TRANSFER TIMING DATA
Figure 9-8 provides detailed timing data for GDMA data transfers that are triggered by external DMA requests.
Please note that read/write timing depends on which memory banks are selected.
To access ROM banks, which is in multiplexing bus mode, by 4-data burst mode, refer to Figure A-1 and Figure
A-2 of appendix A for read/write timing of ROM bank 5.
SCLK
(In_MCLK)
tEMRs
tEMRh
nXDREQ
nXDACK
tEMAf
tEMAr
Min.3 cycles
worst
best
tEMRS
tEMRh
setup time
3.90 ns
0 ns
hold time
delay
(falling)
tEMAf
tEMAr
9.55 ns
9.30 ns
23.30 ns
22.70 ns
delay
(rising)
Figure 9-8. External DMA Requests Detailed Timing (S3C4510X)
9-10
S3C4510B
DMA CONTROLLER
SCLK
(In_MCLK)
tEMRs
tEMRh
nXDREQ
nXDACK
tEMAf
tEMAr
Min.3 cycles
worst
best
tEMRS
tEMRh
setup time
6.31 ns
0 ns
hold time
delay
(falling)
tEMAf
tEMAr
12.19 ns
9.33 ns
28.54 ns
21.87 ns
delay
(rising)
Figure 9-9. External DMA Requests Detailed Timing (S3C4510B)
9-11
DMA CONTROLLER
S3C4510B
CLOCK DESCRIPTION
The internal clock(In_MCLK; This is the operating clock on the S3C4510B) differs from mclko(pad out clock). For
more clear description, internal clock(In_MCLK) is used at this timing diagram. Following Figure 9-9 is the
relationship of internal clock(In_MCLK) and mclko(pad out clock). You must think one more step that is the
concern with mclko.
In_MCLK
MCLKO
MIN 4.03 ns
MAX 10.57 ns
NOTE: Each clock periol is 20 ns.
Figure 9-10. MCLKO and SCLK (In_MCLK)
9-12
S3C4510B
DMA CONTROLLER
SINGLE AND ONE DATA BURST MODE (GDMACON[11] = 0, [9] = 0 )
DREQ and DACK signals are active low.
Recommand
Deasserted Time
In_MCLK
DREQ
DACK
a
b
c
Source
Address
Destination
Address
Address
Data
Source
Data
Destination
data
NOTES:
1. In this region, DMA operation is independent of the number of DREQ signal pulse. For example, although
DREQ signal pulses 3 times in the '¨Í' region, GDMAC transfers data only one time from source address to
destination address. Current DREQ signal is idle state(deasserted) when DACK siganl is idle state
(high). Otherwise, GDMAC recognizes current DREQ signal as next one and transfers next data.
I recommand that DREQ signal is deasserted when DACK signal is active.
2. '¨Î' is three more cycles(3+a cycles). The 'a' is internal system bus acquistion time.
3. '¨Ï' signal falls at negative edge In_MCLK clock after source data is valid.
Figure 9-11. Single and One Data Burst Mode Timing
9-13
DMA CONTROLLER
S3C4510B
SINGLE AND FOUR DATA BURST MODE (GDMACON[11] = 0, [9] = 1 )
DREQ & DACK signals are active low.
In the four data burst mode, GDMA COUNT Register(GDMA CNT) value decreases by 1 after 4 data transfer.
Recommand
Deasserted Time
In_MCLK
DREQ
DACK
Address
Data
S0
S1
S2
S3
D0
D1
D2
D3
S4
GDMA
CNT
N
N-1
NOTE:
Address order is source address0 -> source address1 -> source address 2 -> source address3
-> destination address0 -> destination address1 ->destination address2 -> destination
address3, and Data order is source data0 -> source data1 -> source data2 -> source data3
-> destination data0 -> destination data1 -> destination data2 -> destination data3.
Figure 9-12. Single and Four Data Burst Mode Timing
9-14
S3C4510B
DMA CONTROLLER
BLOCK AND ONE DATA BURST MODE (GDMACON[11] = 1, [9] = 0 )
DREQ and DACK signals are active low.
GDMAC transfers data from DREQ signal is active till GDMA COUNT Register consumes.
Recommand
Deasserted Time
In_MCLK
DREQ
DACK
a
Source
Address
Destination
Address
Source
Address
Destination
Address
Address
Data
Source
Data
Destination
Data
Source
Data
Destination
Data
NOTE:
'¨Í' is in the block mode, GDMAC starts to operate with first DREQ signal. So in the ideal case,
GDMAC don't care the number of DREQ signal pulse. But I recommand that DREQ siganl is
deasserted when DACK signal is active state.
Figure 9-13. Block and One Data Burst Mode Timing
BLOCK AND FOUR DATA BURST (GDMACON[11] = 1, [9] = 1 )
This timing diagram is the same with Single and one data burst exception four data burst.
one data burst; source address0 and source data0 ® destination address0 and destination data0 ® ....
four data burst; source address0 and source data0 ® source address1 and source data1 ® source address2 and
source data2 ® source address3 and source data3 ® destination address0 and destination data0
® destination address1 and destination data1 ® destination address2 and destination data2 ®
destination address3 and destination data3 ® source address4 and source data4 ® ....
NOTE
In the four data burst mode, GDMA COUNT Register value decreases by 1 after 4 data transfer.
9-15
DMA CONTROLLER
S3C4510B
CONTINUOUS AND ONE BURST MODE (GDMACON[14] = 1, [9] = 0 )
DREQ and DACK signals are active low.
Recommand Time
In_MCLK
DREQ
DACK
Address
Data
S0
D0
S1
D1
S2
D2
S3
D3
GDMA
CNT
8
7
6
5
4
3
2
1
0
NOTE:
S# is source address#, and D# is destination address#.
Figure 9-14. Continuous and One Burst Mode Timing
CONTINUOUS AND FOUR DATA BURST MODE (GDMACON[14] = 1, [9] = 1 )
This timing diagram is the same with Continuous and one data burst exception four data burst.
one data burst; source address0 and source data0 ® destination address0 and destination data0 ® source
address1 and source data1 ® destination address1 and destination data1 ® ...
four data burst; source address0 and source data0 ® source address1 and source data1 ® source address2 and
source data2 ® source address3 and source data3 ® destination address0 and destination data0
® destination address1 and destination data1 ® destination address2 and destination data2 ®
destination address2 and destination data2 ® destination address3 and destination data3 ® ...
NOTE
In the four data burst mode, GDMA COUNT Register value decreases by 1 after 4 data transfer.
9-16
S3C4510B
DMA CONTROLLER
DEMAND AND ONE DATA BURST MODE (GDMACON[15] = 1, [9] = 0 )
DREQ and DACK signals are active low.
In_MCLK
DREQ
DACK
Address
Data
S0
D0
S1
D1
S2
D2
S3
D3
GDMA
CNT
8
7
6
5
4
3
2
1
0
NOTE:
S# is source address#, and D# is destination address#.
If GDMA CNT is zero, GDMAC do not transfer data although DREQ signal asserted.
Figure 9-15. Demand and One Data Burst Mode Timing
DEMAND & FOUR DATA BURST MODE ( GDMACON[15] = 1, [9] = 1 )
This timing diagram is the same with Demand & one data burst exception four data burst.
one data burst; source address0 and source data0 ® destination address0 and destination data0 ® ...
four data burst; source address0 and source data0 ® source address1 and source data1 ® source address2 and
source data2 ® source address3 and source data3 ® destination address0 and destination data0
® destination address1 and destination data1 ® destination address2 and destination data2 ®
destination address2 and destination data2 ® destination address3 and destination data3 ® ...
NOTE
If you want to use continuous mode, you must set block mode not single mode.
If you want to use demand mode, you must set single mode not block mode.
9-17
DMA CONTROLLER
S3C4510B
NOTES
9-18
S3C4510B
UART
10 SERIAL I/O (UART)
OVERVIEW
The S3C4510B UART (Universal Asynchronous Receiver/Transmitter) unit provides two independent
asynchronous serial I/O (SIO) ports. Each port can operate in interrupt-based or DMA-based mode. That is, the
UART can generate internal interrupts or DMA requests to transfer data between the CPU and the serial I/O
ports.
The most important features of the S3C4510B UART include:
— Programmable baud rates
— Infra-red (IR) transmit/receive
— Insertion of one or two Stop bits per frame
— Selectable 5-bit, 6-bit, 7-bit, or 8-bit data transfers
— Parity checking
Each SIO unit has a baud rate generator, transmitter, receiver, and a control unit, as shown in Figure 10-1. The
baud-rate generator can be driven by the internal system clock, MCLK, or by the external clock, UCLK. The
transmitter and receiver blocks have independent data buffer registers and data shifters.
Transmit data is written first to the transmit buffer register. From there, it is copied to the transmit shifter and then
shifted out by the transmit data pin, UATXDn. Receive data is shifted in by the receive data pin, UARXDn. It is
then copied from the shifter to the receive buffer register when one data byte has been received.
The SIO control units provide software controls for mode selection, and for status and interrupt generation.
NOTE
For the UART Tx interrupt method, you should write dummy byte to UART Tx buffer register
before initialize UART. With this, you can generate UART Tx interrupt when Tx Buffer empty.
10-1
UART
S3C4510B
Transmit Buffer Register
(UTXBUFn)
Baud Rate Divisor
(UTBUFn)
UATxDn
Transmit Shift Register
0
1
IR Tx
Decoder
Baud Rate Generator
Line Control Register
(ULCONn)
UART Control Register
(UCONn)
UART Status Register
(USTATn)
nUADTRn
nUADSRn
Receive Buffer Register
(URXBUFn)
UARxDn
0
1
Receive Shift Register
IR Rx
Decoder
Figure 10-1. Serial I/O Block Diagram
10-2
S3C4510B
UART
UART SPECIAL REGISTERS
Table 10-1. UART Special Registers Overview
Register
ULCON0
Offset Address
0xD000
0xE000
0xD004
0xE004
0xD008
0xE008
0xD00C
0xE00C
0xD010
0xE010
0xD014
0xE014
0xD018
0xE018
0xD01C
0xE01C
R/W
R/W
R/W
R/W
R/W
R
Description
UART0 line control register
Reset Value
0x00
0x00
0x00
0x00
0xC0
0xC0
0xXX
0xXX
0xXX
0xXX
0x00
0x00
0x00
0x00
0x0
ULCON1
UCON0
UART1 line control register
UART0 control register
UCON1
UART1 control register
USTAT0
UART0 status register
USTAT1
R
UART1 status register
UTXBUF0
UTXBUF1
URXBUF0
URXBUF1
UBRDIV0
UBRDIV1
BRDCNT0
BRDCNT1
BRDCLK0
BRDCLK1
W
UART0 transmit buffer register
UART1 transmit buffer register
UART0 receive buffer register
UART1 receive buffer register
UART0 baud rate divisor register
UART1 baud rate divisor register
UART0 baud rate count register
UART1 baud rate count register
UART0 baud rate clock monitor
UART1 baud rate clock monitor
W
R
R
R/W
R/W
W
W
W
W
0x0
10-3
UART
S3C4510B
UART LINE CONTROL REGISTERS
Table 10-2. ULCON0 and ULCON1 Registers
Registers
ULCON0
Offset Address
0xD000
R/W
R/W
R/W
Description
UART0 line control register
UART1 line control register
Reset Value
0x00
ULCON1
0xE000
0x00
Table 10-3. UART Line Control Register Description
Bit Number
Bit Name
Reset Value
[1:0]
World length (WL)
This two-bit word length value indicates the number of data bits to
be transmitted or received per frame: ’00’ = 5 bits, ’01’ = 6 bits, '10'
= 7 bits, and ’11’ = 8 bits.
[2]
Number of Stop bits
Parity mode (PMD)
This bit specifies how many Stop bits are used to signal end-of-
frame (EOF): "0" = one Stop bit per frame and "1" = two Stop bits
per frame.
[5:3]
The 3-bit parity mode value specifies how parity generation and
checking are to be performed during UART transmit and receive
operations: '0xx' = no parity, ’100’ = odd parity, ’101’ = even parity,
'110' = parity is forced/checked as a "1", and '111' = parity
forced/checked as a "0".
[6]
[7]
Serial Clock Selection
Infra-red mode
This selection bit specifies the clock source.
0 = Internal (MCLK)
1 = External (UCLK)
The S3C4510B UART block supports infra-red (IR) transmit and
receive operations. In IR mode, the transmit period is pulsed at a
rate of 3/16 that of the normal serial transmit rate (when the
transmit data value in the UTXBUF register is zero).
To enable IR mode operation, you set ULCON[7] to "1". Otherwise,
the UART operates in normal mode. In IR receive mode, the
receiver must detect the
3/16 pulsed period to recognize a zero value in the receiver buffer
register, URXBUF, as the IR receive data.
When bit [7] is "0", normal UART mode is selected. When it is "1",
infra-red Tx/Rx mode is selected.
10-4
S3C4510B
UART
31
8
7
6
5
4
3
2
1 0
S
T
B
I
R
X
PMD
WL
[1:0] Word length per frame (WL)
00 = 5 bits
01 = 6 bits
10 = 7 bits
11 = 8 bits
[2] Number of Stop bits at the end of frame (STB)
0 = One stop bit per frame
1 = Two stop bits per frame
[5:3] Parity mode (PMD)
0xx = No parity
100 = Odd parity
101 = Even parity
110 = Parity forced/ checked as 1.
111 = Parity forced/checked as 0.
[6] Serial clock selection (SC)
0 = Internal (MCLK)
1 = External (UCLK)
[7] Infra-red mode selection (IR)
0 = Normal mode operation
1 = Infra-red Tx/Rx mode
Figure 10-2. UART Line Control Registers
10-5
UART
S3C4510B
UART CONTROL REGISTERS
Table 10-4. UCON0 and UCON1 Registers
Registers
UCON0
UCON1
Offset Address
0xD004
R/W
R/W
R/W
Description
UART0 control register
UART1 control register
Reset Value
0x00
0xE004
0x00
Table 10-5. UART Control Register Description
Bit Name Reset Value
Bit Number
[1:0]
Receive mode (RxM)
This two-bit value determines which function is currently able to
read data from the UART receive buffer register, RBR: '00' =
disable Rx mode, '01' = interrupt request, '10' = GDMA channel 0
request, and '11' = GDMA channel 1 request.
[2]
Rx status interrupt
enable
This bit lets the UART generate an interrupt if an exception (a
break, frame error, parity error, or overrun error) occurs during a
receive operation.
If this bit is set to "1", the UART generates a receive status
interrupt. If this bit is "0", the receive status interrupt is not
generated.
[4:3]
Transmit mode (TxM)
This two-bit value determines which function is currently able to
write Tx data to the UART transmit buffer register, UTXBUF. '00' =
disable Tx mode, '01' = interrupt request, '10' = GDMA channel 0
request, and '11' = GDMA channel 1 request.
[5]
[6]
Data set ready (DSR)
Send break
Setting UCON[5] causes the S3C4510B to assert its data set ready
(DSR) signal output, nUADSR. Clearing this bit to "0" causes the
DSR output to be de-asserted.
Setting UCON0/1[6] to "1" causes the UART to send a break. If it is
"0", a break is not sent.
A break is defined as a continuous Low level signal on the transmit
data output with a duration of more than one frame transmission
time.
By setting this bit when the transmitter is empty (transmitter empty
bit, USTAT[7] = "1"), you can use the transmitter to time the frame.
When USTAT[7] is "1", write the transmit buffer register, UTXBUF,
with the data to be transmitted. Then, poll the USTAT[7] value.
When USTAT[7] returns to "1", clear (reset) the send break bit,
UCON0/1[6].
[7]
Look-back mode
Setting this bit causes the UART to enter Loop-back mode. In
Loop-back mode, the transmit data output is sent High level and
the transmit buffer register, UTXBUF, is internally connected to the
receive buffer register, URXBUF.
NOTE: This mode is provided for test purposes only. For
normal operation, this bit should always be "0".
10-6
S3C4510B
UART
31
8
7
6
5
4
3
2
1 0
R
x
S
I
L S D
P B S
B K R
TxM
RxM
[1:0] SIO receive mode selection (RxM)
00 = Disable
01 = Interrupt request
10 = GDMA channel 0 request
11 = GDMA channel 1 request
[2] Receive status interrupt enable (RxSI)
0 = Do not generate receive status interrupt
1 = Generate receive status interrupt
[4:3] SIO transmit mode selection (TxM)
00 = Disable
01 = Interrupt request
10 = GDMA channel 0 request
11 = GDMA channel 1 request
[5] Data set ready (DSR)
0 = Deassert S3C4510B DSR output (nUADSR)
1 = Assert S3C4510B DSR output (nUADSR)
[6] Send break (SBK)
0 = Do not send break
1 = Send break
[7] Loop-back enable (LPB)
0 = Normal operation mode
1 = Enable look-up mode (for testing only)
Figure 10-3. UART Control Registers
10-7
UART
S3C4510B
UART STATUS REGISTER
Table 10-6. UCON0 and UCON1 Registers
Registers
USTAT0
Offset Address
R/W
R
Description
UART0 status register
UART1 status register
Reset Value
0xC0
0xD008
0xE008
USTAT1
R
0xC0
Table 10-7. UART Status Register Description
Bit Name Reset Value
Bit Number
[0]
Overrun error
USTAT[0] is automatically set to "1" whenever an overrun error
occurs during a serial data receive operation. The overrun error
indicates that the new received data has overwritten old received
data before the old data could be read.
If the receive status interrupt enable bit, UCON[2] is "1", a receive
status interrupt is generated if an overrun error occurs.
This bit is automatically cleared to "0" whenever the UART status
register (USTAT) is read.
[1]
[2]
Parity error
Frame error
USTAT[1] is automatically set to "1" whenever a parity error occurs
during a serial data receive operation. If the receive status interrupt
enable bit, UCON[2], is "1", a receive status interrupt is generated
if a parity error occurs.
This bit is automatically cleared to "0" whenever the UART status
register (USTAT) is read.
USTAT[2] is automatically set to "1" whenever a frame error occurs
during a serial data receive operation. A frame error occurs when a
zero is detected instead of the Stop bit(s).
If the receive status interrupt enable bit, UCON[2] is "1", a receive
status interrupt is generated if a frame error occurs.
The frame error bit is automatically cleared to "0" whenever the
UART status register (USTAT) is read.
[3]
[4]
Break interrupt
USTAT[3] is automatically set to "1" to indicate that a break signal
has been received.
If the receive status interrupt enable bit, UCON[2], is "1", a receive
status interrupt is generated if a break occurs.
The break interrupt bit is automatically cleared to "0" when you
read the UART status register.
Data terminal ready
(DTR)
The USTAT[4] bit indicates the current signal level at the data
terminal ready (DTR) pins (nUADTR). When this bit is "1", the level
at the DTR pin (nUADTR) is Low. When it is "0", the DTR pin is
High level.
10-8
S3C4510B
UART
Table 10-7. UART Status Register Description (Continued)
Bit Number
Bit Name
Reset Value
[5]
Receive data ready
USTAT[5] is automatically set to "1" whenever the receive data
buffer register (URXBUF) contains valid data received over the
serial port. The receive data can then be read from the URXBUF.
When this bit is "0", the URXBUF does not contain valid data.
Depending on the current setting of the UART receive mode bits,
UCON[1:0], an interrupt or a DMA request is generated when
USTAT[5] is "1".
[6]
Tx Buffer register empty USTAT[6] is automatically set to "1" when the transmit buffer
register (UTXBUF) does not contain valid data. In this case, the
UTXBUF can be written with the data to be transmitted.
When this bit is "0", the UTXBUF contains valid Tx data that has
not yet been copied to the transmit shift register. In this case, the
UTXBUF cannot be written with new Tx data.
Depending on the current setting of the SIO transmit mode bits,
UCON[4:3], an interrupt or a DMA request will be generated
whenever USTAT[6] is "1".
[7]
Transmit complete (TC) USTAT[7] is automatically set to "1" when the transmit buffer
register has no valid data to transmit and when the Tx shift register
is empty. When the transmitter empty bit is "1", it indicates to
software that it can now disable the transmitter function block.
10-9
UART
S3C4510B
31
8
7
6
5
4
3
2
1
0
T R D B
B D T K
E R R D
T
C
F P O
E E V
[0] Overrun error (OV)
0 = No overrun error during receive
1 = Overrun error (generate receive status interrupt if UCON[2] is 1)
[1] Parity error (PE)
0 = No parity error during receive
1 = Parity error (generate receive status interrupt if UCON[2] is 1)
[2] Frame error (FE)
0 = No frame error during receive
1 = Frame error (generate receive status interrupt if UCON[2] is 1)
[3] Break detect (BKD)
0 = No break received
1 = Break received (generate receive stauts interrupt if UCON[2] is 1)
[4] Data terminal ready (DTR)
0 = DTR pin (nUADTR) is High
1 = DTR pin (nUADTR) is Low
[5] Receive data ready (RDR)
0 = No vaild data in the receive buffer register
1 = Vaild data present in the receive buffer register
(issue interrupt or DMa request if UCON[1:0] is set)
[6] Transmit buffer register empty (TBE)
0 = Vaild data in transmit holding register
1 = No data in transmit holdign register
(as the setting of UCON[4:3], interrupt or GDMA request is generated)
[7] Transmit complete (TC)
0 = Transmit in progress
1 = Transmit complete; no data for Tx
Figure 10-4. UART Status Registers
10-10
S3C4510B
UART
UART TRANSMIT BUFFER REGISTER
The UART transmit buffer registers, UTXBUF0 and UTXBUF1, contain an 8-bit data value to be transmitted over
the UART channel.
Table 10-8. UXTBUF0 and UXTBUF1 Registers
Registers
UTXBUF0
Offset Address
0xD00C
R/W
W
Description
UART0 transmit buffer register
UART1 transmit buffer register
Reset Value
0xXX
UTXBUF1
0xE00C
W
0xXX
Table 10-9. UART Status Register Description
Bit Name Reset Value
Transmit data
Bit Number
This field contains the data to be transmitted over the single
channel UART.
[7:0]
When this register is written, the transmit buffer register empty bit
in the status register, USTAT[6], should be "1". This is to prevent
overwriting of transmit data that may already be present in the
UTXBUF.
Whenever the UTXBUF is written with a new value, the transmit
register empty bit, USTAT[6], is automatically cleared to "0".
31
8 7 6 5 4 3 2 1 0
Transmit Data
[7:0] Transmit data for UART
Figure 10-5. UART Transmit Buffer Registers
10-11
UART
S3C4510B
UART RECEIVE BUFFER REGISTER
The UART receive buffer registers, URXBUF0 and URXBUF1, contain an 8-bit data value for received serial
data.
Table 10-10. UXRBUF0 and UXRBUF1 Registers
Registers
URXBUF0
Offset Address
0xD010
R/W
R
Description
UART0 receive buffer register
UART1 receive buffer register
Reset Value
0xXX
URXBUF1
0xE010
R
0xXX
Table 10-11. UART Transmit Register Description
Bit Name Reset Value
Receive data
Bit Number
[7:0]
This field contains the data received over the single channel
UART.
When the UART finishes receiving a data frame, the receive data
ready bit in the UART status register, USTAT[5], should be "1".
This prevents reading invalid receive data that may already be
present in the URXBUF.
Whenever the URXBUF is read, the receive data ready
bit(USTAT[5]) is automatically cleared to "0".
31
8 7 6 5 4 3 2 1 0
Receive Data
[7:0] Receive data for UART
Figure 10-6. UART Receive Buffer Registers
10-12
S3C4510B
UART
UART BAUD RATE DIVISOR REGISTER
The values stored in the baud rate divisor registers, UBRDIV0 and UBRDIV1, let you determine the serial Tx/Rx
clock rate (baud rate) as follows:
BRGOUT = (MCLK2 or UCLK)/(CNT0 + 1)/(16^CNT1)/16
Table 10-12. UBRDIV0 and UBRDIV0 Registers
Registers
UBRDIV0
UBRDIV1
Offset Address
0xD014
R/W
R/W
R/W
Description
UART0 baud rate divisor register
UART1 baud rate divisor register
Reset Value
0x00
0xE014
0x00
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8 7 6 5 4 3 2 1 0
CNT0
CNT1
[3:0] Baud reate divisor value CNT1
xxx0 = divide by 1
xxx1 = divide by 16
[15:4] Time constant value for CNT0
Figure 10-7. UART Baud Rate Divisor Registers
10-13
UART
S3C4510B
UART BAUD RATE COUNT AND CLOCK REGISTERS
For test purpose only, the internal baud rate up counters, BRDCNT0 and BRDCNT1, can be directly accessed
using register addressing. In addition, the baud rate clock can be monitored through the UART data set ready
ports, nUADSR.
If the BRDCLKn monitor value is "1", the baud rate clock can be monitored at the nUADSR pin. If it is "0" (its
default value), or if you write a "0" to the BRDCLKn address, the UARD DSR signal output to the nUADSR port
depends on the current setting of UART control register bit 5.
Table 10-13. BRDCNTn and BRDCLKn Registers
Register
BRDCNT0
BRDCNT1
BRDCLK0
BRDCLK1
Offset Address
0xD018
R/W
W
Description
Reset Value
UART0 baud rate count register
UART1 baud rate count register
UART0 baud rate clock monitor
UART1 baud rate clock monitor
0x0
0x0
0x0
0x0
0xE018
W
0xD01C
W
0xE01C
W
Baud Rate Divisor
(UBRDIVn)
Baud Rate Clock
Compare Logic
Match Generator
Baud Rate up Counter
(URDCNTn)
nUADSR
BRDCLKn
MCLK
Chip Internal
Chip External
Figure 10-8. UART Baud Rate Clock Test Scheme
10-14
S3C4510B
UART
UART BAUD RATE EXAMPLES
UART BRG input clock, MCLK2 is the system clock frequency divided by 2.
If the system clock frequency is 50 MHz and MCLK2 is selected, the maximum BRGOUT output clock rate is
MCLK2/16 (= 1.5625 MHz).
UCLK is the external clock input pin for UART0, UART1. UART BRG input clock, MCLK2, UCLK can be selected
by UCCON[6] register.
CNT0
CNT1
MCLK2
UCLK
BRGOUT
12-bit Counter
Divide by 1 or 16
Divide by 16
Sample Clock
SC
NOTE:
CNT0 = UBTDIVn [15:4], CNT1 = UBRDIVn [3:0], SC = ULCON [6]
Figure 10-9. UART Baud Rate Generator (BRG)
Table 10-14. Typical Baud Rates Examples of UART
Baud Rates
(BRGOUT)
1200
MCLK2 = 25 MHz
UCLK = 33 MHz
CNT0
1301
650
324
162
80
CNT1
Freq.
1200.1
Dev.(%)
0.0
CNT0
1735
867
433
216
108
53
CNT1
Freq.
Dev.(%)
0
0
0
0
0
0
0
0
0
0
1
1
0
0
0
0
0
0
0
0
1200.08
0.0064
0.0064
0.0064
0.0064
0.45
2400
2400.2
0.0
2400.15
4800
4807.7
0.2
4800.31
9600
9585.9
- 0.1
0.5
9600.61
19200
19290.1
38109.8
57870.4
111607.1
223214.28
520833.34
19113.15
38580.15
57870.37
115740.74
231481.48
416666.66
38400
40
- 0.8
0.5
0.47
57600
26
35
0.47
115200
230400
460860
13
- 3.1
3.12
13.01
17
0.47
6
8
0.47
2
4
9.59
10-15
UART
S3C4510B
< Receiver >
Stop
(1-2)
UTXDn
THRE
Start
Data Bits (5-8)
Parity
Start
WR_THR
INT_TXD
< Receiver >
Stop
(1-2)
URXDn
INT_RXD
URXBUF
Start
Data Bits (5-8)
Parity
Start
Data Bits
Previous Receive Data
Valid Receive Data
Figure 10-10. Interrupt-Based Serial I/O Timing Diagram (Tx and Rx Only)
10-16
S3C4510B
UART
<Transmitter >
TxE
TxD
Select DMA Mode
Stop
(1-2)
Start
Data Bits (5-8)
Parity
THRE
WR_THR
nXDREQ
nXDACK
Figure 10-11. DMA-Based Serial I/O Timing Diagram (Tx Only)
< Receiver >
RxE
Select DMA Mode
Stop
(1-2)
URXDn
URXBUFn
nXDREQ
nXDACK
Start
Data Bits (5-8)
Parity
Start
Data Bits
Previous Receive Data
Valid Receive Data
Figure 10-12. DMA-Based Serial I/O Timing Diagram (Rx Only)
10-17
UART
S3C4510B
SIO Frame
Data Bits
Start
Bit
Stop
Bit
0
1
0
1
0
0
1
1
0
1
Figure 10-13. Serial I/O Frame Timing Diagram (Normal UART)
IR Transmit Frame
Start
Bit
Stop
Bit
Data Bits
3/16T
0
1
0
1
0
0
1
1
0
1
7/16T 6/16T
Bit frame = T
Figure 10-14. Infra-Red Transmit Mode Frame Timing Diagram
10-18
S3C4510B
UART
IR Receive Frame
Data Bits
Start
Bit
Stop
Bit
3/16T
0
1
0
1
0
0
1
1
0
1
Bit frame = T
13/16T
Figure 10-15. Infra-Red Receive Mode Frame Timing Diagram
10-19
UART
S3C4510B
NOTES
10-20
S3C4510B
32-BIT TIMERS
11 32-BIT TIMERS
OVERVIEW
The S3C4510B has two 32-bit timers. These timers can operate in interval mode or in toggle mode. The output
signals are TOUT0 and TOUT1, respectively.
You enable or disable the timers by setting control bits in the timer control register, TCON. An interrupt request is
generated whenever a timer count-out (down count) occurs.
INTERVAL MODE OPERATION
In interval mode, a timer generates a one-shot pulse of a preset timer clock duration whenever a time-out occurs.
This pulse generates a time-out interrupt that is directly output at the timer's configured output pin (TOUTn). In
this case, the timer frequency monitored at the TOUTn pin is calculated as:
fTOUT = fMCLK / Timer data value
TOGGLE MODE OPERATION
In toggle mode, the timer pulse continues to toggle whenever a time-out occurs. An interrupt request is generated
whenever the level of the timer output signal is inverted (that is, when the level toggles). The toggle pulse is
output directly at the configured output pin.
Using toggle mode, you can achieve a flexible timer clock range with 50% duty. In toggle mode, the timer
frequency monitored at the TOUTn pin is calculated as follows:
fTOUT = fMCLK / (2 * Timer data value)
fTOUT
Interval Mode
Time-out
Time-out
Time-out
fTOUT
Toggle Mode
(Initial TOUTn is 0)
Figure 11-1. Timer Output Signal Timing
11-1
32-BIT TIMERS
S3C4510B
TIMER OPERATION GUIDELINES
The block diagram in Figure 11-2 shows how the 32-bit timers are configured in the S3C4510B. The following
guidelines apply to timer functions.
— When a timer is enabled, it loads a data value to its count register and begins decrement the count register
value.
— When the timer interval expires, the associated interrupt is generated. The base value is then reloaded and
the timer continues decrement its count register value.
— If a timer is disabled, you can write a new base value into its registers.
— If the timer is halted while it is running, the base value is not automatically re-loaded.
32-Bit Timer Data
Register (TDATAn)
Auto
Re-load
INTPND and
INTMSK
fMCLK
32-Bit Timer Count
Register (TCNTn)
[Down Counter]
Interrupt
Request
PND
TMOD.TEn
Pulse
Generator
TMOD.TMDn
TMOD.TCLRn
TOUTn
Port 16, Port 17
Data Out
IOPCON.TOENn
Figure 11-2. 32-Bit Timer Block Diagram
11-2
S3C4510B
32-BIT TIMERS
TIMER MODE REGISTER
The timer mode register, TMOD, is used to control the operation of the two 32-bit timers. TMOD register settings
are described in Figure 11-3.
Table 11-1. TMOD Register
Register
TMOD
Offset Address
R/W
Description
Timer mode register
Reset Value
0x6000
R/W
32’h00000000
31
6
5
4
3
2
1
0
T
C
L
R
1
T
C
L
R
0
T
D
M
1
T
D
M
0
T
E
1
T
E
0
[0] Timer 0 enable (TE0)
0 = Disable timer 0
1 = Enable timer 0
[1] Timer 0 mode selection (TMD0)
0 = Interval mode
1 = Toggle mode
[2] Timer 0 initial TOUT0 value (TCLR0)
0 = Initial TOUT0 is 0 in toggle mode
1 = Initial TOUT0 is 1 in toggle mode
[3] Timer 1 enable (TE1)
0 = Disable timer 1
1 = Enable timer 1
[4] Timer 1 mode selection (TMD1)
0 = Interval mode
1 = Toggle mode
[5] Timer 1 initial TOUT1 value (TCLR1)
0 = Initial TOUT1 is 0 in toggle mode
1 = Initial TOUT1 is 1 in toggle mode
Figure 11-3. Timer Mode Register (TMOD)
11-3
32-BIT TIMERS
S3C4510B
TIMER DATA REGISTERS
The timer data registers, TDATA0 and TDATA1, contain a value that specifies the time-out duration for each
timer. The formula for calculating the time-out duration is: (Timer data + 1) cycles.
Table 11-2. TDATA0 and TDATA1 Registers
Register
TDATA0
TDATA1
Offset Address
0x6004
R/W
R/W
R/W
Description
Timer 0 data register
Reset Value
0x00000000
0x00000000
0x6008
Timer 1 data register
31
0
Receive Data
[31:0] Timer 0/1 data value
Figure 11-4. Timer Data Registers (TDATA0, TDATA1)
TIMER COUNT REGISTERS
The timer count registers, TCNT0 and TCNT1, contain the current timer 0 and 1 count value, respectively, during
normal operation.
Table 11-3. TCNT0 and TCNT1 Registers
Register
TCNT0
Offset Address
0x600C
R/W
R/W
R/W
Description
Timer 0 counter register
Reset Value
0xFFFFFFFF
0xFFFFFFFF
TNCT1
0x6010
Timer 1 counter register
31
0
Timer Count
[31:0] Timer 0/1 count value
Figure 11-5. Timer Counter Registers (TCNT0, TCNT1)
11-4
S3C4510B
I/O PORTS
12 I/O PORTS
OVERVIEW
The S3C4510B has 18 programmable I/O ports. You can configure each I/O port to input mode, output mode, or
special function mode. To do this, you write the appropriate settings to the IOPMOD and IOPCON registers. User
can set filtering for the input ports using IOPCON register.
The modes of the ports from port0 to port7 are determined only by the IOPMOD register. But port[11:8] can be
used as xINTREQ[3:0], port[13:12] as nXDREQ[1:0], port[15:14] as nXDACK[1:0], port[16] as TOUT0, or port[17]
as TOUT1 depending on the settings in IOPCON register.
VDD
IOPMOD
IOPCON
Alternate Functions
Port0 - Port7
Port8/xINTREQ0
Output
Latch
IOPDATA
(Write)
Port11/xINTREQ3
Port12/nXDREQ0
Port13/nXDREQ1
Port14/nXDACK0
Port15/nXDACK1
Port16/TOUT0
IOPDATA
(Read)
Port17/TOUT1
Active
On/Off & Edge
Detection
Input
Latch
Filter
On/Off
Interrupt or DMA
Request
IOPCON
IOPCON
Figure 12-1. I/O Port Function Diagram
12-1
I/O PORTS
S3C4510B
I/O PORT SPECIAL REGISTERS
Three registers control the I/O port configuration: IOPMOD, IOPCON, and IOPDATA. These registers are
described in detail below.
I/O PORT MODE REGISTER (IOPMOD)
The I/O port mode register, IOPMOD, is used to configure the port pins, P17–P0.
NOTE
If the port is used for a special function such as an external interrupt request, an external DMA request,
or acknowledge signal and timer outputs, its mode is determined by the IOPCON register, not by
IOPMOD.
Table 12-1. IOPMOD Register
Register
IOPMOD
Offset Address
R/W
Description
I/O port mode register
Reset Value
0x5000
R/W
0x00000000
31
18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
[0] I/O port mode bit for port 0
0 = Input
1 = Output
[1] I/O port mode bit for port 1
0 = Input
1 = Output
[2] I/O port mode bit for port 2
0 = Input
1 = Output
[17] I/O port mode bit for port 17
0 = Input
1 = Output
Figure 12-2. I/O Port Mode Register (IOPMOD)
12-2
S3C4510B
I/O PORTS
I/O PORT CONTROL REGISTER (IOPCON)
The I/O port control register, IOPCON, is used to configure the port pins, P17–P8.
NOTE
If the port is used for a special function such as an external interrupt request, an external DMA request,
or acknowledge signal and timer outputs, its mode is determined by the IOPCON register, not by
IOPMOD.
For the special input ports, S3C4510A provides 3-tap filtering. If the input signal levels are same for the three
system clock periods, that level is taken as input for dedicated signals such as external interrupt requests and
external DMA requests.
Table 12-2. IOPCON Register
Register
IOPCON
Offset Address
R/W
Description
I/O port control register
Reset Value
0x5004
R/W
0x00000000
12-3
I/O PORTS
S3C4510B
31 30 29 28 27 26 25
23 22
20 19
15 14
10 9
5
4
3
2
1
0
T T
O O
E E
N N
X
I
R
Q
3
X
I
R
Q
2
X
I
R
Q
1
X
I
R
Q
1
D
A
K
1
D
A
K
0
D
R
Q
1
D
R
Q
0
1
0
[4:0] Control external interrupt request 0 input for port 8 (xIRQ0)
[4] Port 8 for xINTREQ0
0 = Disable
1 = Enable
[3] 0 = Active Low
1 = Active High
[2] 0 = Filtering off
1 = Filtering on
[1:0] 00 = Level detection
01 = Rising edge detection
10 = Falling edge detection
11 = Both edge detection
[9:5] Control external interrupt request 1 input for port 9 (xIRQ1)
(See control external interrupt request 1.)
[14:10] Control external interrupt request 2 input for port 10 (xIRQ2)
(See control external interrupt request 2.)
[19:15] Control external interrupt request 3 input for port 11 (xIRQ3)
(See control external interrupt request 3.)
[22:20] Control external DMA request 0 input for port 12 (DRQ0)
[22] Port 12 for nXDREQ0
0 = Disable
1 = Enable
[21] 0 = Filtering off
1 = Filtering on
[20] 0 = Active Low
1 = Active High
[25:23] Control external DMA request 1 input for port 13 (DRQ1)
[25] Port 13 for nXDREQ1
0 = Disable
1 = Enable
[24] 0 = Filtering off
[23] 0 = Active Low
1 = Filtering on
1 = Active High
[27:26] Control external DMA acknowledge 0 output for port 14 (DAK0)
[27] Port 14 for nXDACK0
0 = Disable
1 = Enable
[26] 0 = Active Low
1 = Active High
[29:28] Control external DMA acknowledge 1 output for port 15 (DAK1)
[29] Port 15 for nXDACK1
0 = Disable
1 = Enable
[28] 0 = Active Low
1 = Active High
[30] Control timeout 0 for port 16 (TOEN0)
0 = Disable
1 = Enable
[31] Control timeout 1 for port 17 (TOEN1)
0 = Disable
1 = Enable
Figure 12-3. I/O Port Control Register (IOPCON)
12-4
S3C4510B
I/O PORTS
I/O PORT DATA REGISTER (IOPDATA)
The I/O port data register, IOPDATA, contains one-bit read values for I/O ports that are configured to input mode
and one-bit write values for ports that are configured to output mode. Bits[17:0] of the 18-bit I/O port register
value correspond directly to the 18 port pins, P17–P0.
Table 12-3. IOPDATA Register
Register
IOPDATA
Offset Address
R/W
Description
I/O port data register
Reset Value
0x5008
R/W
Undefined
31
18 17 16 15 14 13 12 11 10 9
P P P P P P P P P P P P P P P P P P
17 16 15 14 13 12 11 10 9
8 7 6 5 4 3 2 1 0
8
7 6 5 4 3 2 1 0
[17:0] I/O port read/write values for ports 17-0 (P0-P17)
NOTE: The values in the I/O port data register reflect the signal level on the
respective I/O port pins. When the ports are configured to output mode,
the bit reflects the ports write value. When the port is configured to input
mode, the bit reflects the ports read value.
Figure 12-4. I/O Port Data Register (IOPDATA)
12-5
I/O PORTS
S3C4510B
MCLKO
xINTREQn
Internal INTREQn
IOPCON.xIRQn [1:0] (= 00)
IOPCON.xIRQn [1:0] (= 01)
IOPCON.xIRQn [1:0] (= 11)
Figure 12-5. External Interrupt Request Timing (Active High)
MCLKO
xINTREQn
Internal INTREQn
IOPCON.xIRQn [1:0] (= 00)
IOPCON.xIRQn [1:0] (= 01)
IOPCON.xIRQn [1:0] (= 10)
IOPCON.xIRQn [1:0] (= 11)
Figure 12-6. External Interrupt Request Timing (Active Low)
12-6
S3C4510B
INTERRUPT CONTROLLER
13 INTERRUPT CONTROLLER
OVERVIEW
The S3C4510B interrupt controller has a total of 21 interrupt sources. Interrupt requests can be generated by
internal function blocks and at external pins.
The ARM7TDMI core recognizes two kinds of interrupts: a normal interrupt request (IRQ), and a fast interrupt
request (FIQ). Therefore all S3C4510B interrupts can be categorized as either IRQ or FIQ. The S3C4510B
interrupt controller has an interrupt pending bit for each interrupt source.
Four special registers are used to control interrupt generation and handling:
— Interrupt priority registers. The index number of each interrupt source is written to the pre-defined interrupt
priority register field to obtain that priority. The interrupt priorities are pre-defined from 0 to 20.
— Interrupt mode register. Defines the interrupt mode, IRQ or FIQ, for each interrupt source.
— Interrupt pending register. Indicates that an interrupt request is pending. If the pending bit is set, the interrupt
pending status is maintained until the CPU clears it by writing a "1" to the appropriate pending register. When
the pending bit is set, the interrupt service routine starts whenever the interrupt mask register is "0". The
service routine must clear the pending condition by writing a "1" to the appropriate pending bit. This avoids
the possibility of continuous interrupt requests from the same interrupt pending bit.
— Interrupt mask register. Indicates that the current interrupt has been disabled if the corresponding mask
bit is "1". If an interrupt mask bit is "0" the interrupt will be serviced normally. If the global mask bit (bit 21) is
set to "1", no interrupts are serviced. However, the source's pending bit is set if the interrupt is generated.
When the global mask bit has been set to "0", the interrupt is serviced.
13-1
INTERRUPT CONTROLLER
S3C4510B
INTERRUPT SOURCES
The 21 interrupt sources in the S3C4510B interrupt structure are listed, in brief, as follows:
Table 13-1. S3C4510B Interrupt Sources
Index Values
[20]
[19]
[18]
[17]
[16]
[15]
[14]
[13]
[12]
[11]
[10]
[9]
Interrupt Sources
I2C-bus interrupt
Ethernet controller MAC Rx interrupt
Ethernet controller MAC Tx interrupt
Ethernet controller BDMA Rx interrupt
Ethernet controller BDMA Tx interrupt
HDLC channel B Rx interrupt
HDLC channel B Tx interrupt
HDLC channel A Rx interrupt
HDLC channel A Tx interrupt
Timer 1 interrupt
Timer 0 interrupt
GDMA channel 1 interrupt
GDMA channel 0 interrupt
UART 1 receive and error interrupt
UART 1 transmit interrupt
UART 0 receive and error interrupt
UART 0 transmit interrupt
External interrupt 3
[8]
[7]
[6]
[5]
[4]
[3]
[2]
External interrupt 2
[1]
External interrupt 1
[0]
External interrupt 0
13-2
S3C4510B
INTERRUPT CONTROLLER
INTERRUPT CONTROLLER SPECIAL REGISTERS
INTERRUPT MODE REGISTER
Bit settings in the interrupt mode register, INTMOD, specify if an interrupt is to be serviced as a fast interrupt
(FIQ) or a normal interrupt (IRQ).
Table 13-2. INTMOD Register
Register
INTMOD
Offset
Address
R/W
Description
Reset Value
0x4000
R/W
Interrupt mode register
0x00000000
31
21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
INTMOD
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
[20:0] Interrupt mode bits
NOTE: Each of the 21 bits in the interrupt mode enable register, INTMOD,
corresponds to an interrupt source. When the source interrupt mode bit
is set to 1, the interrupt is processed by the ARM7TDMI core in FIQ
(fast interrupt) mode. Otherwise, it is processed in IRQ mode (normal
interrupt). The 21 interrupt sources are mapped as follows:
[20] I2C interrupt
[19] Ethernet controller MAC Rx interrupt
[18] Ethernet controller MAC Tx interrupt
[17] Ethernet controller BDMA Rx interrupt
[16] Ethernet controller BDMA Tx interrupt
[15] HDLC channel B Rx interrupt
[14] HDLC channel B Tx interrupt
[13] HDLC channel A Rx interrupt
[12] HDLC channel A Tx interrupt
[11] Timer 1 interrupt
[10] Timer 0 interrupt
[9] GDMA channel 1 interrupt
[8] GDMA channel 0 interrupt
[7] UART1 receive and error interrupt
[6] UART1 transmit interrupt
[5] UART0 receive and error interrupt
[4] UART0 transmit interrupt
[3] External interrupt 3
[2] External interrupt 2
[1] External interrupt 1
[0] External interrupt 0
Figure 13-1. Interrupt Mode Register (INTMOD)
13-3
INTERRUPT CONTROLLER
S3C4510B
INTERRUPT PENDING REGISTER
The interrupt pending register, INTPND, contains interrupt pending bits for each interrupt source. This register
has to be cleared at the top of an interrupt service routine.
Table 13-3. INTPND Register
Register
INTPND
Offset Address
R/W
Description
Interrupt pending register
Reset Value
0x4004
R/W
0x00000000
31
21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
INTPND
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
[20:0] Interrupt pending bits
NOTE:
Each of the 21 bits in the interrupt mode pending register, INTPND,
corresponds to an interrupt source. When an interrupt request is
generated, its pending bit is set to 1. The service routine must then
clear the pending condition by writing a 1 to the apropriate pending
bit at start. The 21 interrupt sources are mapped as follows:
[20] I2C interrupt
[19] Ethernet controller MAC Rx interrupt
[18] Ethernet controller MAC Tx interrupt
[17] Ethernet controller BDMA Rx interrupt
[16] Ethernet controller BDMA Tx interrupt
[15] HDLC channel B Rx interrupt
[14] HDLC channel B Tx interrupt
[13] HDLC channel A Rx interrupt
[12] HDLC channel A Tx interrupt
[11] Timer 1 interrupt
[10] Timer 0 interrupt
[9] GDMA channel 1 interrupt
[8] GDMA channel 0 interrupt
[7] UART1 receive and error interrupt
[6] UART1 transmit interrupt
[5] UART0 receive and error interrupt
[4] UART0 transmit interrupt
[3] External interrupt 3
[2] External interrupt 2
[1] External interrupt 1
[0] External interrupt 0
Figure 13-2. Interrupt Pending Register (INTPND)
13-4
S3C4510B
INTERRUPT CONTROLLER
INTERRUPT MASK REGISTER
The interrupt mask register, INTMSK, contains interrupt mask bits for each interrupt source.
Table 13-4. INTMSK Register
Register
INTMSK
Offset Address
R/W
Description
Interrupt mask register
Reset Value
0x4008
R/W
0x003FFFFF
31
21 20 19 18 17 16 15 14 13 12 11 10 9
8 7 6 5 4 3 2 1 0
INTMSK
G X X X X X X X X X X X X X X X X X X X X X
[20:0] Individual interrupt mask bits
NOTE:
Each of the 21 bits in the interrupt mask register, INTMSK,
(except for the global mask bit, G) corresponds to an interrupt source.
When a source interrupt mask bit is 1, the interrupt is not serviced by the
CPU when the corresponding interrupt request is generated. If the mask
bit is 0, the interrupt is serviced upon request. And if global mask bit
(bit 21) is 1, no interrupts are serviced. (However, the source pending
bit is set whenever the interrupt is generated.) After the global mask bit
is cleared, the interrupt is serviced. The 21 interrupt sources are mapped
as follows:
[20] I2C interrupt
[19] Ethernet controller MAC Rx interrupt
[18] Ethernet controller MAC Tx interrupt
[17] Ethernet controller BDMA Rx interrupt
[16] Ethernet controller BDMA Tx interrupt
[15] HDLC channel B Rx interrupt
[14] HDLC channel B Tx interrupt
[13] HDLC channel A Rx interrupt
[12] HDLC channel A Tx interrupt
[11] Timer 1 interrupt
[10] Timer 0 interrupt
[9] GDMA channel 1 interrupt
[8] GDMA channel 0 interrupt
[7] UART1 receive and error interrupt
[6] UART1 transmit interrupt
[5] UART0 receive and error interrupt
[4] UART0 transmit interrupt
[3] External interrupt 3
[2] External interrupt 2
[1] External interrupt 1
[0] External interrupt 0
[21] Global interrupt mask bit
0 = Enable interrupt requests
1 = Disable all interrupt requests
Figure 13-3. Interrupt Mask Register (INTMSK)
13-5
INTERRUPT CONTROLLER
S3C4510B
INTERRUPT PRIORITY REGISTERS
The interrupt priority registers, INTPRI0–INTPRI5, contain information about which interrupt source is assigned to
the pre-defined interrupt priority field. Each INTPRIn register value determines the priority of the corresponding
interrupt source. The lowest priority value is priority 0, and the highest priority value is priority 20.
The index value of each interrupt source is written to one of the above 21 positions (see Figure 13-4). The
position value then becomes the written interrupt's priority value. The index value of each interrupt source is
listed in Table 13-1.
Table 13-5. Interrupt Priority Register Overview
Register
INTPRI0
Offset Address
0x400C
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Description
Interrupt priority register 0
Reset Value
0x03020100
0x07060504
0x0B0A0908
0x0F0E0D0C
0x13121110
0x00000014
INTPRI1
INTPRI2
INTPRI3
INTPRI4
INTPRI5
0x4010
Interrupt priority register 1
Interrupt priority register 2
Interrupt priority register 3
Interrupt priority register 4
Interrupt priority register 5
0x4014
0x4018
0x401C
0x4020
26 25
23
0
14 13 12 11 10 9
8
7
0
6
0
5
0
4
3
2
1 0
29 28 27
24
22
21 20 19 18 17 16 15
31 30
INTPRI0
INTPRI1
INTPRI2
INTPRI3
INTPRI4
INTPRI5
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
PRIORITY3
PRIORITY7
PRIORITY11
PRIORITY15
PRIORITY19
0
0
0
0
0
0
0
0
0
0
0
0
PRIORITY2
PRIORITY6
PRIORITY10
PRIORITY14
PRIORITY18
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
PRIORITY1
PRIORITY5
PRIORITY9
PRIORITY0
PRIORITY4
PRIORITY8
Low
Priority
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
PRIORITY13
PRIORITY17
PRIORITY12
PRIORITY16
PRIORITY20
High
Priority
0
0
0
0
0
0
0
0
0
0
0 0 0 0 0
High Priority
Low Priority
Figure 13-4. Interrupt Priority Register (INTPRIn)
13-6
S3C4510B
INTERRUPT CONTROLLER
INTERRUPT OFFSET REGISTER
The interrupt offset register, INTOFFSET, contains the interrupt offset address of the interrupt, which has the
highest priority among the pending interrupts. The content of the interrupt offset address is "bit position value of
the interrupt source << 2".
If all interrupt pending bits are "0" when you read this register, the return value is "0x00000054".
This register is valid only under the IRQ or FIQ mode in the ARM7TDMI. In the interrupt service routine, you
should read this register before changing the CPU mode.
INTOSET_FIQ/INTOSET_IRQ register can be used to get the highest priority interrupt without CPU mode
change. Other usages are similar to INTOFFSET.
NOTE
If the lowest interrupt priority (priority 0) is pending, the INTOFFSET value will be "0x00000000". The
reset value will, therefore, be changed to "0x00000054" (to be differentiated from interrupt pending
priority 0).
Table 13-6. INTOFFSET Register
Register
Offset
R/W
Description
Reset Value
Address
INTOFFSET
0x4024
0x4030
0x4034
R
R
R
Interrupt offset register
0x00000054
0x00000054
0x00000054
INTOSET_FIQ
INTOSET_IRQ
FIQ interrupt offset register
IRQ interrupt offset register
13-7
INTERRUPT CONTROLLER
S3C4510B
INTERRUPT PENDING BY PRIORITY REGISTER
The interrupt pending by priority register, INTPNDPRI, contains interrupt pending bits, which are re-ordered by
the INTPRIn register settings. INTPNDPRI[20] is mapped to the interrupt source of whichever bit index is written
into the priority 20 field of the INTPRIn registers.
This register is useful for testing. To validate the interrupt pending by priority value, you can obtain the highest
priority pending interrupt from the interrupt offset register, INTOFFSET.
Table 13-7. INTPNDPRI Register
Register
Offset Address
R/W
Description
Reset Value
INTPNDPRI
0x4028
R
Interrupt pending by priority
0x00000000
INTERRUPT PENDING TEST REGISTER
The interrupt pending test register, INTPNDTST, is used to set or clear INTPND and INTPNDPRI. If user writes
data to this register, it is written into both the INTPND register and INTPNDPRI register. The interrupt pending
test register, INTPNDTST, is also useful for testing.
For INTPND, the same bit position is updated with the new coming data. For INTPNDPRI, the mapping bit
position by INTPRIn registers is updated with the new coming data to keep with the contents of the INTPND
register.
Table 13-8. INTPNDTST Register
Register
Offset
R/W
Description
Reset Value
Address
INTPNDTST
0x402C
W
Interrupt pending test register
0x00000000
13-8
S3C4510B
ELECTRICAL DATA
14 ELECTRICAL DATA
OVERVIEW
This chapter describes the S3C4510B and S3C4510X electrical data.
ABSOLUTE MAXIMUM RATINGS
Table 14-1. Absolute Maximum Ratings
Parameter
Supply Voltage
Symbol
Rating
Units
VDD/VDDA
– 0.3 to 3.8
V
VIN
– 0.3 to VDD + 0.3
– 0.3 to 5.5
DC input Voltage
3.3 V I/O
V
5 V-tolerant
IIN
DC input current
mA
°C
± 10
TOPR
TSTG
Operating temperature
Storage temperature
0 to 70
– 40 to 125
°C
ABSOLUTE MAXIMUM RATINGS
Table 14-2. Recommended Operating Conditions
Parameter
Symbol
Rating
Units
VDD/VDDA
Supply Voltage
3.0 to 3.6
upto 50
820
V
fOSC
LF
Oscillator frequency
MHz
pF
External loop filter capacitance
Commercial temperature
TA
0 to 70
°C
NOTE: It is strongly recommended that all the supply pins (V /V
) be powered from the same source to avoid power
DD DDA
latch-up.
14-1
ELECTRICAL DATA
S3C4510B
D.C. ELECTRICAL CHARACTERISTICS
Table 14-3. D.C Electrical Characteristics
°
VDD = 3.3 V 0.3 V, VEXT = 5 0.25 V, TA = 0 to 70 C (in case of 5 V-tolerant I/O)
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
(1)
High level input voltage LVCMOS
interface
–
2.0
–
–
V
VIH
(1)
Low level input voltage
LVCMOS
interface
–
–
–
0.8
V
V
VIL
Switching threshold
VT
LVCMOS
LVCMOS
LVCMOS
–
–
1.4
–
–
2.0
–
Schmitt trigger positive-going threshold
VT+
VT–
Schmitt trigger negative-going
threshold
0.8
–
IIH
VIN = VDD
High level input current
Low level input current
Input buffer
– 10
10
–
10
60
mA
mA
Input buffer
with pull-up
30
IIL
VIN = VSS
Input buffer
– 10
– 60
–
10
Input buffer
with pull-
down
– 30
– 10
VOH
VDD
–
High level output voltage Type B1 to
B16(2)
–
–
V
IOH = – 1 mA
0.05
IOH = – 1 mA
IOH = – 2 mA
IOH = – 4 mA
IOH = – 6 mA
IOL = 1 mA
Type B1
Type B2
Type B4
Type B6
2.4
VOL
Low level output voltage Type B1 to
B16(2)
0.05
0.4
V
IOL = 1 mA
IOL = 2 mA
IOL = 4 mA
IOL = 6 mA
Type B1
Type B2
Type B4
Type B6
IOZ
VOUT = VSS or
VDD
Tri-state output leakage current
– 10
10
mA
IDD
VDD = 3.6 V,
Maximum operating current
230
mA
fMCLK = 50MHz
NOTES:
1. All 5 V-tolerant inputs have less than 0.2 V hysterics.
2. Type B1 means 1 mA output driver cells, and Type B6/B24 means 6 mA/24 mA output driver cells.
14-2
S3C4510B
ELECTRICAL DATA
Table 14-4. A.C Electrical Characteristics for S3C4510X
°
(TA = 0 to 70 C, VDD = 3.0 V to 3.6 V)
Signal Name
Description
Min
4.03
4.99
Max
10.57
12.02
3.90
Edge
P
tMCLKOd
tEMZ
MCLKO delay for Internal Positive Edge Clock (MCLK)
Memory Control Signal High-Z Time
ExtMREQ Setup Time
N
P
tEMRs
tEMRh
tEMAr
ExtMREQ Hold Time
0
P
ExtMACK Rising Edge Delay Time
9.55
9.30
4.75
6.76
3.24
3.81
3.36
23.30
22.70
11.50
16.53
7.90
N
N
N
N
N
N
P
tEMAf
ExtMACK Falling Edge Delay Time
tADDRh
tADDRd
tNRCS
tNROE
tNWBE
tRDs
Address Hold Time
Address Delay Time
ROM/SRAM/Flash Bank Chip Select Delay Time
ROM/SRAM or External I/O Bank Output Enable Delay
ROM/SRAM or External I/O Bank Write Byte Enable Delay
Read Data Setup Time
9.24
8.13
10.82
N
N
N
N
P
tRDh
Read Data Hold Time
0
tWDd
Write Data Delay Time (SRAM or External I/O) (ref:nWBE)
Write Data Hold Time (SRAM or External I/O) (ref:MCLK)
DRAM Row Address Strobe Active Delay
DRAM Row Address Strobe Release Delay
DRAM Column Address Strobe Read Active Delay
DRAM CAS Signal Release Read Delay Time
DRAM Column Address Strobe Write Active Delay
DRAM CAS Signal Release Write Delay Time
DRAM Bank Write Enable Delay Time
DRAM Bank Out Enable Delay Time
External I/O Bank Chip Select Delay Time
DRAM Write Data Delay Time (DRAM)
DRAM Write Data Hold Time (DRAM)
External Wait Setup Time
1.86
2.05
3.53
4.95
3.58
3.57
3.60
3.62
3.93
3.80
3.58
4.96
2.70
4.49
4.86
8.59
11.99
8.70
8.62
8.72
8.73
9.54
9.26
8.74
11.97
6.42
4.82
tWDh
tNRASf
tNRASr
tNCASf
tNCASr
tNCASwf
tNCASwr
tNDWE
tNDOE
tNECS
tWDDd
tWDDh
tWs
N
P
P
N
N
N
N
N
N
N
N
N
tWh
External Wait Hold Time
0
NOTE: The edge (N) is calculated from SCLK(MCLK) falling and (P) is rising.
14-3
ELECTRICAL DATA
S3C4510B
Table 14-5. A.C Electrical Characteristics for S3C4510B
°
(TA = 0 to 70 C, VDD = 3.0 V to 3.6 V)
Signal Name
Description
Min
4.07
5.08
Max
9.37
Edge
P
tMCLKOd
tEMZ
MCLKO delay for Internal Positive Edge Clock(MCLK)
Memory Control Signal High-Z Time
ExtMREQ Setup Time
11.76
6.31
N
P
tEMRs
tEMRh
tEMAr
ExtMREQ Hold Time
0
P
ExtMACK Rising Edge Delay Time
12.19
9.33
5.16
6.13
3.96
3.82
4.70
28.54
21.87
12.08
14.35
9.29
N
N
N
N
N
N
P
tEMAf
ExtMACK Falling Edge Delay Time
tADDRh
tADDRd
tNRCS
tNROE
tNWBE
tRDs
Address Hold Time
Address Delay Time
ROM/SRAM/Flash Bank Chip Select Delay Time
ROM/SRAM or External I/O Bank Output Enable Delay
ROM/SRAM or External I/O Bank Write Byte Enable Delay
Read Data Setup Time
8.96
11.13
12.46
N
N
N
N
P
tRDh
Read Data Hold Time
0
tWDd
Write Data Delay Time (SRAM or External I/O) (ref:nWBE)
Write Data Hold Time (SRAM or External I/O) (ref:MCLK)
DRAM Row Address Strobe Active Delay
DRAM Row Address Strobe Release Delay
DRAM Column Address Strobe Read Active Delay
DRAM CAS Signal Release Read Delay Time
DRAM Column Address Strobe Write Active Delay
DRAM CAS Signal Release Write Delay Time
DRAM Bank Write Enable Delay Time
DRAM Bank Out Enable Delay Time
External I/O Bank Chip Select Delay Time
DRAM Write Data Delay Time (DRAM)
DRAM Write Data Hold Time (DRAM)
External Wait Setup Time
2.50
1.94
3.84
5.70
3.77
4.23
3.78
4.27
4.81
4.15
4.12
7.00
3.27
5.65
4.45
9.00
13.31
8.84
9.88
8.86
9.99
11.25
9.71
9.63
16.32
7.58
4.46
tWDh
tNRASf
tNRASr
tNCASf
tNCASr
tNCASwf
tNCASwr
tNDWE
tNDOE
tNECS
tWDDd
tWDDh
tWs
N
P
P
N
N
N
N
N
N
N
N
N
tWh
External Wait Hold Time
0
NOTE: The edge (N) is calculated from SCLK(MCLK) falling and (P) is rising.
14-4
S3C4510B
MECHANICAL DATA
15 MECHANICAL DATA
OVERVIEW
This section describes the mechanical data for the S3C4510B 208-pin QFP package.
15-1
MECHANICAL DATA
S3C4510B
30.60 BSC
28.00 BSC
0-7
+ 0.05
0.15 - 0.06
0.08 MAX
208-QFP-2828B
#144
+ 0.07
0.20 - 0.03
#1
0.25 MIN
3.40 ± 0.20
4.10 MAX
0.50 BSC
0.08 MAX
(1.25)
NOTE
: Dimensions are in millimeters.
Figure 15-1. 208-QFP-2828B Package Dimensions
15-2
S3C4510B
APPENDIX A
APPENDIX A
TEST ACCESS PORT
This section describes relevant sections of the IEEE Standard 1149.1 Compatible Test Access Port (TAP). This
standard applies to the Test Access Port and Boundary Scan (JTAG) specification, which is supported by the
S3C4510B microcontoller.
In test mode, package pads are monitored by the serial scan circuitry. This is done to support connectivity testing
during manufacturing, as well as system diagnostics. JTAG control is not used to drive internal data out of the
S3C4510B.
To conform with IEEE 1194.1, the S3C4510B has a TAP controller, an instruction register, a bypass register, and
an ID register. These components are described in detail below.
A-1
APPENDIX A
S3C4510B
TAP CONTROLLER
The TAP controller is responsible for interpreting the sequence of logical values on the TMS signal. It is a
synchronous state machine which controls the JTAG logic (see Figure B-1). In Figure B-1, the value shown next
to each curved arrow represents the value of the TMS signal as it is sampled on the rising edge of the TCK
signal.
Test Login Reset
1
0
1
Run-Test/Idle
Select-DR_Scan
Select-IR_Scan
0
0
0
Capture-DR
Capture-IR
0
0
Shift-DR
Shift-IR
1
Exit1-DR
0
1
Exit1-IR
0
Pause-DR
1
Pause-IR
1
Exit2-DR
1
Exit2-IR
1
Update-DR
Update-IR
1
0
1
0
Figure A-1. TAP Controller State Machine
A-2
S3C4510B
APPENDIX A
BOUNDARY SCAN REGISTER
The S3C4510B scan chain implementation uses a 233-bit boundary scan register. This register contains bits for
all device signals and clock pins, and for associated control signals.
All bi-directional pins have two register bits in the boundary scan register for pin data. Each pin is controlled by
an associated control bit in the boundary scan register. The twenty-three bits in the boundary scan register define
the output enable signals for associated groups of bi-directional and tri-stateable pins. The control bits and their
bit positions are listed in Table B-1.
Table A-1. Boundary Scan Control Bits
Name
Bit Number
Name
Bit Number
Name
penb [1]
penb [0]
d_enb
Bit Number
penb [17]
penb [16]
penb [15]
penb [14]
penb [13]
penb [12]
penb [11]
penb [10]
9
penb [9]
penb [8]
penb [7]
penb [6]
penb [5]
penb [4]
penb [3]
penb [2]
33
36
39
42
45
48
51
54
57
12
15
18
21
24
27
30
60
127
184
192
211
222
dis_bus
mdio_oe
txcben
txcaen
BOUNDARY SCAN DEFINITIONS
The boundary scan bit definitions are listed in Tables B-2 through B-5:
— The first column in the table defines the bit's ordinal position in the boundary scan register. The shift register
cell nearest TDO (that is, the first bit to be shifted out) is defined as bit 0. The last bit to be shifted out is bit
number 232.
— The second column refers to one of the four S3C4510B cell types: jtin1, jtbi1, and jtout1.
— The third column lists the pin name of pin-related cells or defines the name of bi-directional control register
bits.
— The fourth column lists the pin type. TS-Output indicates a tri-stateable output pin, and OD-I/O denotes an
open-drain bi-directional pin.
— The fifth column indicates the associated boundary scan register control bit for bi-directional, tri-state output.
A-3
APPENDIX A
S3C4510B
Table A-2. Boundary Scan Definitions (Page 1)
Bit
Number
Cell
Type
Pin/Cell
Name
Pin
Type
Output
CTL Cell Number
Bit
Cell
Type
Pin/Cell
Name
Pin
Type
Output
CTL Cell
0
1
2
3
4
5
jtin 1
UARXD1
Input
Output
Output
Input
–
–
–
–
–
–
32
33
34
35
36
37
jtbi1
jtout1
jtbi1
P[10]
penb[9]
P[9]o
Input
–
–
–
jtout 1 nUADSR0
jtout 1
jtin 1
jtin 1
jtbi 1
UATXD0
UADTR0
UARXD0
SDA
TS-Output penb[9]
jtbi1
P[9]i
Input
–
–
–
–
Input
jtout1
jtbi1
penb[8]
P[8]
OD-
TS-Output
Output
6
7
jtbi 1
jtbi 1
SDA
SCL
OD-Input
–
–
38
39
jtbi1
P[8]
Input
–
–
–
OD-
jtout1
penb[7]
Output
8
jtbi 1
jtout 1
jtbi 1
jtbi 1
jtout 1
jtbi 1
jtbi 1
jtout 1
jtbi 1
jtbi 1
jtout 1
jtbi 1
jtbi 1
jtout 1
jtbi 1
jtbi 1
jtout 1
jtbi 1
jtbi 1
jtout 1
jtbi 1
jtbi 1
jtout 1
jtbi 1
SCL
pend[17]
P[17]
OD-Input
–
–
–
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
jtbi1
jtbi1
jtout1
jtbi1
jtbi1
jtout1
jtbi1
jtbi1
jtout1
jtbi1
jtbi1
jtout1
jtbi1
jtbi1
jtout1
jtbi1
P[7]
P[7]
TS-Output penb[7]
9
Input
–
–
–
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
TS-Output penb[17]
penb[6]
P[6]
P[17]
Input
–
–
–
TS-Output penb[6]
penb[16]
P[16]
P[6]
Input
–
–
–
TS-Output penb[16]
penb[5]
P[5]
P[16]
Input
–
–
–
TS-Output penb[5]
penb[15]
P[15]
P[5]
Input
–
–
–
TS-Output penb[15]
penb[4]
P[4]
P[15]
Input
–
–
–
TS-Output penb[4]
penb[14]
P[14]
P[4]
Input
–
–
–
TS-Output penb[14]
penb[3]
P[3]
P[14]
Input
–
–
–
TS-Output penb[3]
penb[13]
P[13]
P[3]
Input
–
–
TS-Output penb[13]
penb[2]
P[2]
–
P[13]
Input
–
–
–
TS-Output
Input
penb[2]
penb[12]
P[12]
jtbi1
P[2]
–
TS-Output penb[12]
jtout1
jtbi1
penb[1]
P[1]o
P[1]i
–
–
P[12]
Input
–
–
–
TS-Output
Input
penb[1]
penb[11]
P[11]
jtbi1
–
–
TS-Output penb[11]
jtout1
jtbi1
penb[0]
P[0]
–
P[11]
Input
–
–
–
TS-Output
Input
penb[0]
–
penb[10]
P[10]
jtbi1
P[0]
TS-Output penb[10]
jtbi1
XDATA[31] TS-Output
denb
A-4
S3C4510B
APPENDIX A
Table A-3. Boundary Scan Definitions (Page 2)
Bit
Number
Cell
Type
Pin/Cell
Name
Pin
Type
Output
CTL Cell Number
Bit
Cell
Type
Pin/Cell
Name
Pin
Type
Output
CTL Cell
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
XDATA[31]
Input
–
denb
–
96
jtbi1
jbti1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtbi1
jtout1
XDATA[15]
Input
–
denb
–
XDATA[30] TS-Output
XDATA[30] Input
XDATA[29] TS-Output
XDATA[29] Input
XDATA[28] TS-Output
XDATA[28] Input
XDATA[27] TS-Output
XDATA[27] Input
XDATA[26] TS-Output
XDATA[26] Input
XDATA[25] TS-Output
XDATA[25] Input
XDATA[24] TS-Output
XDATA[24] Input
XDATA[23] TS-Output
XDATA[23] Input
XDATA[22] TS-Output
XDATA[22] Input
XDATA[21] TS-Output
XDATA[21] Input
XDATA[20] TS-Output
XDATA[20] Input
XDATA[19] TS-Output
XDATA[19] Input
XDATA[18] TS-Output
XDATA[18] Input
XDATA[17] TS-Output
XDATA[17] Input
XDATA[16] TS-Output
XDATA[16] Input
XDATA[15] TS-Output
97
XDATA[14] TS-Output
XDATA[14] Input
XDATA[13] TS-Output
XDATA[13] Input
XDATA[12] TS-Output
XDATA[12] Input
XDATA[11] TS-Output
XDATA[11] Input
XDATA[10] TS-Output
XDATA[10] Input
XDATA[9] TS-Output
XDATA[9] Input
XDATA[8] TS-Output
XDATA[8] Input
XDATA[7] TS-Output
XDATA[7] Input
XDATA[6] TS-Output
XDATA[6] Input
XDATA[5] TS-Output
XDATA[5] Input
XDATA[4] TS-Output
XDATA[4] Input
XDATA[3] TS-Output
XDATA[3] Input
XDATA[2] TS-Output
XDATA[2] Input
XDATA[1] TS-Output
XDATA[1] Input
XDATA[0] TS-Output
98
denb
–
99
denb
–
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
denb
–
denb
–
denb
–
denb
–
denb
–
denb
–
denb
–
denb
–
denb
–
denb
–
denb
–
denb
–
denb
–
denb
–
denb
–
denb
–
denb
–
denb
–
denb
–
denb
–
denb
–
denb
–
denb
–
–
denb
–
denb
–
XDATA[0]
denb
Input
–
denb
–
A-5
APPENDIX A
S3C4510B
Table A-4. Boundary Scan Definitions (Page 3)
Bit
Cell
Pin/Cell
Name
Pin
Type
Output
CTL Cell Number
Bit
Cell
Type
Pin/Cell
Name
Pin
Type
Output
CTL Cell
Number Type
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
jtout1 PADDR[21]
jtout1 PADDR[20]
jtout1 PADDR[19]
jtout1 PADDR[18]
jtout1 PADDR[17]
jtout1 PADDR[16]
jtout1 PADDR[15]
jtout1 PADDR[14]
jtout1 PADDR[13]
jtout1 PADDR[12]
jtout1 PADDR[11]
jtout1 PADDR[10]
jtout1 PADDR[9]
jtout1 PADDR[8]
jtout1 PADDR[7]
jtout1 PADDR[6]
jtout1 PADDR[5]
jtout1 PADDR[4]
jtout1 PADDR[3]
jtout1 PADDR[2]
jtout1 PADDR[1]
jtout1 PADDR[0]
jtout1 EXTMACK
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
Output
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
–
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
jtout1
jtout1
jtout1
jtout1
jtout1
jtout1
jtout1
jtout1
jtout1
jtout1
jtin1
nCAQS[0]
nRAS[3]
nRAS[2]
nRAS[1]
nRAS[0]
nRCS[5]
nRCS[4]
nRCS[3]
nRCS[2]
nRCS[1]
CLKSEL
nRESET
MCLK
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
TS-O
Input
Input
Input
Output
Input
TS-O
Input
Input
TS-O
Input
TS-O
TS-O
TS-O
TS-O
–
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
–
jtin1
–
jtck
–
jtout1
jtin1
MCLKO
CLKOEN
nRCS[0]
B0SIZE[1]
B0SIZE[0]
nOE
–
–
jtout1
jtin1
dis_bus
–
jtin1
–
jtout1
jtin1
dis_bus
nEWAIT
nECS[3]
nECS[2]
nECS[1]
nECS[0]
dis_bus
UCLK
–
jtout
dis_bus
jtout1
jtout1
jtout1
jtout1
jtin1
dis_bus
dis_bus
jtin1
EXTMREQ
nWBE[3]
nWBE[2]
nWBE[1]
nWBE[0]
nDWE
–
dis_bus
jtout1
jtout1
jtout1
jtout1
jtout1
jtout1
jtout1
jtout1
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
dis_bus
–
Input
Input
Output
–
–
jtin1
TMODE
MDC
–
jtout1
jtin1
–
LITTLE
mdio_oe
MDIO
–
nCAS[3]
nCAS[2]
nCAS[1]
jtout1
jtbi1
–
–
mdio_oe
–
TS-O
Input
jtbi1
MDIO
A-6
S3C4510B
APPENDIX A
Table A-5. Boundary Scan Definitions (Page 4)
Bit
Cell
Pin/Cell
Name
Pin
Type
Output
CTL Cell Number
Bit
Cell
Type
Pin/Cell
Name
Pin
Type
Output
CTL Cell
Number Type
192
193
jtout1
jtin1
TX_EN/
TXEN_10M
Output
–
–
213
214
jtin1
nDCDB
Input
–
TX_CLK/
TXCLK_10
M
Input
jtin1
nCTSB
Input
–
194
jtout1
TX_ERR/
PCOMP_1
0M
Output
–
215
jtout1
TXDB
Output
–
195
196
197
jtout1
jtout1
jtout1
TXD3
TXD2
Output
Output
Output
–
–
–
216
217
218
jtout1
jtin1
nRTSB
RXDB
Output
Input
–
–
–
TXD1/
jtout1
nDTRB
Output
LOOP10
198
199
200
jtout1
jtin1
TXD0/
TXD_10M
Output
Input
–
–
–
219
220
221
jtout1
jtbi1
txcaen
TXCA
TXCA
–
–
txcaen
–
COL/
COL_10M
Output
Input
jtin1
RX_CLK/
RXCLK_10
M
Input
jtbi1
201
202
203
204
205
jtin1
jtin1
jtin1
jtin1
jtin1
RX_ERR
RXD3
Input
Input
Input
Input
Input
–
–
–
–
–
222
223
224
225
226
jtout1
jtin1
nSYNCA
RXCA
Output
Input
–
–
–
–
–
RXD2
jtin1
nDCDA
nCTSA
TXDA
Input
RXD1
jtin1
Input
RXD0/
jtout1
Output
RXD_10M
206
207
jtin1
jtin1
RX_DV/
LINK10
Input
Input
–
–
227
228
jtout1
jtin1
nRTSA
RXDA
Output
Input
–
–
CRS/
CRS_10M
208
209
210
211
212
jtout1
jtbi1
txcben
TXCB
–
–
229
230
231
232
jtout1
jtout1
jtout1
jtin1
nDTRA
nUADSR1
UATXD1
UADTR1
Output
Output
Output
Input
–
–
–
–
TS-Out
Input
txcben
jtbi1
TXCB
–
–
–
jtout1
jtin1
nSYNCB
RXCB
Output
Input
NOTE : TS-O is tri-state output.
A-7
APPENDIX A
S3C4510B
JTBI1
JTIN1
SHIFT
DINP0N
MODE 0
SETN
TDO0
0
MUX
D
0
1
TDI0
DOUT0
1
Q
D
MUX
Q
JTOUT1
MODE 1
DINP1
TDO1
0
1
MUX
D
0
TDI0
DOUT1
Q
D
MUX
1
Q
TCK
UPDATE
JTCK
SHIFT
0
MUX
1
D
TDI
TDO
Q
TCK
Figure A-2. S3C4510B Scan Cells
A-8
S3C4510B
APPENDIX A
INSTRUCTION REGISTER
The instruction register is four bits in length. There is no parity bit. The fixed value ’0001’ is loaded into the
instruction register during the CAPTURE-IR controller state.
The TAP machines supports the following public instructions. However, the S3C4510B boundary scan logic only
supports EXTEST, IDCODE, BYPASS, and SAMPLE/PRELOAD instructions. The remaining instructions are
used for ARM7TDMI core testing and debugging.
Table A-6. Public Instructions
Instruction
Binary Code
0000
EXTEST
SCAN_N
INTEST
IDCODE
BYPASS
CLAMP
HIGHZ
0010
1100
1110
1111
0101
0111
CLAMPZ
1001
SAMPLE/PRELOAD
RESTART
0011
0100
A-9
APPENDIX A
S3C4510B
--
Samsung Electronics Co.
-- S3C4510B BSDL
--
-- Version 1.1 01-27-99
-- Revision List:
--
--
1) Pin name NC changed to LITTLE
2) 1194 -> 1149
-- Package Type: QFP2828B
--
entity S3C4510B is
generic (PHYSICAL_PIN_MAP : string := "QFP2828B");
port (
nUADTR1
UATXD1
nUADSR1
: in
: outbit;
: outbit;
bit;
nDTRA
RXDA
: outbit;
: inbit;
nRTSA
TXDA
nCTSA
nDCDA
RXCA
: outbit;
: outbit;
: inbit;
: inbit;
: inbit;
nSYNCA
TXCA
nDTRB
RXDB
: outbit;
: inoutbit;
: outbit;
: inbit;
nRTSB
TXDB
nCTSB
nDCDB
RXCB
: outbit;
: outbit;
: inbit;
: inbit;
: inbit;
nSYNCB
TXCB
: outbit;
: inoutbit;
A-10
S3C4510B
APPENDIX A
CRS_CRS_10M
: inbit;
RX_DV_LINK10
RXD
RX_ERR
: inbit;
: inbit_vector(0 to 3);
: inbit;
RX_CLK_RXCLK_10M
: inbit;
COL_COL_10M
TXD
TX_ERR_PCOMP_10M
TX_CLK_TXCLK_10M
TX_EN_TXEN_10M
: inbit;
: outbit_vector(0 to 3);
: outbit;
: inbit;
: outbit;
MDIO
LITTLE
MDC
: inoutbit;
: inbit;
: outbit;
TCK
TMS
TDI
TDO
nTRST
TMODE
UCLK
: inbit;
: inbit;
: inbit;
: outbit;
: inbit;
: inbit;
: inbit;
nECS
: outbit_vector(0 to 3);
nEWAIT
nOE
: inbit;
: outbit;
B0SIZE
: inbit_vector(0 to 1);
CLKOEN
MCLKO
MCLK
nRESET
CLKSEL
: inbit;
: outbit;
: inbit;
: inbit;
: inbit;
nRCS
nRAS
nCAS
nDWE
nWBE
: outbit_vector(0 to 5);
: outbit_vector(0 to 3);
: outbit_vector(0 to 3);
: outbit;
: outbit_vector(0 to 3);
ExtMREQ
ExtMACK
ADDR
: inbit;
: outbit;
: outbit_vector(0 to 21);
XDATA
: inoutbit_vector(0 to 31);
A-11
APPENDIX A
S3C4510B
P
SCL
: inoutbit_vector(0 to 17);
: inoutbit;
SDA
: inoutbit;
UARXD0
nUADTR0
UATXD0
nUADSR0
UARXD1
VDDP
VDDI
: inbit;
: inbit;
: outbit;
: outbit;
: inbit;
: linkagebit_vector(0 to 10);
: linkagebit_vector(0 to 10);
: linkagebit_vector(0 to 11);
: linkagebit_vector(0 to 10)
VSSP
VSSI
);
A-12
S3C4510B
APPENDIX A
use STD_1149_1_1149.all;
attribute PIN_MAP of S3C4510B : entity is PHYSICAL_PIN_MAP;
-- QFP2828B Pin Map
--
-- No-connects: 49
--
constant QFP2828B : PIN_MAP_STRING :=
"nUADTR1 : 3, " &
"UATXD1 : 4, " &
"nUADSR1 : 5, " &
"nDTRA : 6, " &
"RXDA : 7, " &
"nRTSA : 8, " &
"TXDA : 9, " &
"nCTSA : 10, " &
"nDCDA : 13, " &
"RXCA : 14, " &
"nSYNCA : 15, " &
"TXCA : 16, " &
"nDTRB : 17, " &
"RXDB : 18, " &
"nRTSB : 19, " &
"TXDB : 20, " &
"nCTSB : 23, " &
"nDCDB : 24, " &
"RXCB : 25, " &
"nSYNCB : 26, " &
"TXCB : 27, " &
"CRS_CRS_10M : 28, " &
"RX_DV_LINK10 : 29, " &
"RXD : (30, 33, 34, 35), " &
"RX_ERR : 36, " &
"RX_CLK_RXCLK_10M : 37, " &
A-13
APPENDIX A
S3C4510B
"COL_COL_10M : 38, " &
"TXD : (39, 40, 43, 44), " &
"TX_ERR_PCOMP_10M : 45, " &
"TX_CLK_TXCLK_10M : 46, " &
"TX_EN_TXEN_10M : 47, " &
"MDIO : 48, " &
"LITTLE : 49, " &
"MDC : 50, " &
"TCK : 58, " &
"TMS : 59, " &
"TDI : 60, " &
"TDO : 61, " &
"nTRST : 62, " &
"TMODE : 63, " &
"UCLK : 64, " &
"nECS : (67, 68, 69, 70), " &
"nEWAIT : 71, " &
"nOE : 72, " &
"B0SIZE : (73, 74), " &
"CLKOEN : 76, " &
"MCLKO : 77, " &
"MCLK : 80, " &
"nRESET : 82, " &
"PCLKSEL : 83, " &
"nRCS : (75, 84, 85, 86, 87, 88), " &
"nRAS : (89, 90, 91, 94), " &
"nCAS : (95, 96, 97, 98), " &
"nDWE : 99, " &
"nWBE : (100, 101, 102, 107), " &
"ExtMREQ : 108, " &
"ExtMACK : 109, " &
-- A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15 A16 A17 A18 A19 A20 A21
"ADDR : (110, 111, 112, 113, 114, 115, 116, 117, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 132, 133,
134, 135), " &
-- D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 D10 D11 D12 D13 D14 D15 D16 D17 D18 D19 D20
D21 D22 D23 D24 D25 D26 D27 D28 D29 D30 D31
"XDATA : (136, 137, 138, 139, 140, 141, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 159, 160,
161,162, 163, 164, 165, 166, 169, 170, 171, 172, 173, 174, 175), " &
A-14
S3C4510B
APPENDIX A
-- P0 P1 P2 P3 P4 P5 P6 P7 P8 P9 P10 P11 P12 P13 P14 P15 P16 P17
"P : (176, 179, 180, 181, 182, 183, 184, 185, 186, 189, 190, 191, 192, 193, 194, 195, 196, 199), " &
"SCL : 200, " &
"SDA : 201, " &
"UARXD0 : 202, " &
"nUADTR0 : 203, " &
"UATXD0 : 204, " &
"nUADSR0 : 205, " &
"UARXD1 : 206, " &
"VDDP : 1, 21, 41, 53, 78, 103, 118, 142, 157, 177, 197, " &
"VDDI : 11, 31, 51, 65, 92, 105, 130, 155, 167, 187, 207, " &
"VSSP : 2, 22, 42, 54, 79, 93, 106, 131, 156, 168, 188, 208, " &
"VSSI : 12, 32, 52, 66, 81, 104, 119, 143, 158, 178, 198 ";
A-15
APPENDIX A
S3C4510B
attribute TAP_SCAN_IN of TDI : signal is true;
attribute TAP_SCAN_OUT of TDO : signal is true;
attribute TAP_SCAN_MODE of TMS : signal is true;
attribute TAP_SCAN_RESET of nTRST : signal is true;
attribute TAP_SCAN_CLOCK of TCK : signal is true;
attribute INSTRUCTION_LENGTH of S3C4510B : entity is 4;
attribute INSTRUCTION_OPCODE of S3C4510B : entity is
"EXTEST (0000)," &
"SCAN_N (0010)," &
"INTEST (1100)," &
"IDCODE (1110)," &
"BYPASS (1111)," &
"CLAMP (0101)," &
"HIGHZ (0111)," &
"CLAMPZ (1001)," &
"SAMPLE (0011)," &
"RESTART (0100)";
-- S3C4510B's IDCODE is the ARM7TDMI's IDCODE.
attribute REGISTER_ACCESS of S3C4510B : entity is
"0001" &
-- version
"111100" & -- design center
"0011110000" &
"11110000111" &
"1";
-- sequence number
-- Samsung
-- required by 1149.1
attribute REGISTER_ACCESS of S3C4510B : entity is
"IDCODE (IDCODE)," &
"BOUNDARY (INTEST, SAMPLE, EXTEST)," &
"BYPASS (CLAMP, HIGHZ, BYPASS)";
attribute BOUNDARY_CELLS of S3C4510B : entity is "BC_4, BC_2, BC_1";
attribute BOUNDARY_LENGTH of S3C4510B : entity is 233;
attribute BOUNDARY_REGISTER of S3C4510B : entity is
-- num cell port
function safe [ccell disval rslt]
"0 ( BC_2, UARXD1,
"1 ( BC_1, nUADSR0,
"2 ( BC_1, UATXD0,
"3 ( BC_2, nUADTR0,
input, X) ," &
output2, X) ," &
output2, X) ," &
input, X) ," &
A-16
S3C4510B
APPENDIX A
"4 ( BC_2, UARXD0,
"5 ( BC_1, SDA,
input, X) ," &
output3, 1, 5, 1, Z) ," & -- Open-drain Output
"6 ( BC_2, SDA,
"7 ( BC_1, SCL,
"8 ( BC_2, SCL,
input, X) ," &
output3, 1, 7, 1, Z) ," & -- Open-drain Output
input, X) ," &
"9 ( BC_1, *,
"10 ( BC_1, P(17),
"11 ( BC_2, P(17),
controlr, 1) ," & --P_ENB(17)
output3, X, 9, 1, Z) ," &
input, X) ," &
"12 ( BC_1, *,
"13 ( BC_1, P(16),
"14 ( BC_2, P(16),
controlr, 1) ," & --P_ENB(16)
output3, X, 12, 1, Z) ," &
input, X) ," &
"15 ( BC_1, *,
"16 ( BC_1, P(15),
"17 ( BC_2, P(15),
controlr, 1) ," & --P_ENB(15)
output3, X, 15, 1, Z) ," &
input, X) ," &
"18 ( BC_1, *,
"19 ( BC_1, P(14),
"20 ( BC_2, P(14),
controlr, 1) ," & --P_ENB(14)
output3, X, 18, 1, Z) ," &
input, X) ," &
"21 ( BC_1, *,
"22 ( BC_1, P(13),
"23 ( BC_2, P(13),
controlr, 1) ," & --P_ENB(13)
output3, X, 21, 1, Z) ," &
input, X) ," &
"24 ( BC_1, *,
"25 ( BC_1, P(12),
"26 ( BC_2, P(12),
controlr, 1) ," & --P_ENB(12)
output3, X, 24, 1, Z) ," &
input, X) ," &
"27 ( BC_1, *,
"28 ( BC_1, P(11),
"29 ( BC_2, P(11),
controlr, 1) ," & --P_ENB(11)
output3, X, 27, 1, Z) ," &
input, X) ," &
"30 ( BC_1, *,
controlr, 1) ," & --P_ENB(10)
output3, X, 30, 1, Z) ," &
input, X) ," &
controlr, 1) ," & --P_ENB(9)
output3, X, 33, 1, Z) ," &
input, X) ," &
"31 ( BC_1, P(10),
"32 ( BC_2, P(10),
"33 ( BC_1, *,
"34 ( BC_1, P(9),
"35 ( BC_2, P(9),
"36 ( BC_1, *,
"37 ( BC_1, P(8),
"38 ( BC_2, P(8),
controlr, 1) ," & --P_ENB(8)
output3, X, 36, 1, Z) ," &
input, X) ," &
"39 ( BC_1, *,
"40 ( BC_1, P(7),
"41 ( BC_2, P(7),
controlr, 1) ," & --P_ENB(7)
output3, X, 39, 1, Z) ," &
input, X) ," &
A-17
APPENDIX A
S3C4510B
"42 ( BC_1, *,
"43 ( BC_1, P(6),
"44 ( BC_2, P(6),
controlr, 1) ," & --P_ENB(6)
output3, X, 42, 1, Z) ," &
input, X) ," &
"45 ( BC_1, *,
"46 ( BC_1, P(5),
"47 ( BC_2, P(5),
controlr, 1) ," & --P_ENB(5)
output3, X, 45, 1, Z) ," &
input, X) ," &
"48 ( BC_1, *,
"49 ( BC_1, P(4),
"50 ( BC_2, P(4),
controlr, 1) ," & --P_ENB(4)
output3, X, 48, 1, Z) ," &
input, X) ," &
"51 ( BC_1, *,
"52 ( BC_1, P(3),
"53 ( BC_2, P(3),
controlr, 1) ," & --P_ENB(3)
output3, X, 51, 1, Z) ," &
input, X) ," &
"54 ( BC_1, *,
"55 ( BC_1, P(2),
"56 ( BC_2, P(2),
controlr, 1) ," & --P_ENB(2)
output3, X, 54, 1, Z) ," &
input, X) ," &
"57 ( BC_1, *,
"58 ( BC_1, P(1),
"59 ( BC_2, P(1),
controlr, 1) ," & --P_ENB(1)
output3, X, 57, 1, Z) ," &
input, X) ," &
"60 ( BC_1, *,
"61 ( BC_1, P(0),
"62 ( BC_2, P(0),
controlr, 1) ," & --P_ENB(0)
output3, X, 60, 1, Z) ," &
input, X) ," &
"63 ( BC_1, XDATA(31),
"64 ( BC_2, XDATA(31),
output3, X, 127, 1, Z) ," &
input, X) ," &
"65 ( BC_1, XDATA(30),
"66 ( BC_2, XDATA(30),
output3, X, 127, 1, Z) ," &
input, X) ," &
"67 ( BC_1, XDATA(29),
"68 ( BC_2, XDATA(29),
output3, X, 127, 1, Z) ," &
input, X) ," &
"69 ( BC_1, XDATA(28),
"70 ( BC_2, XDATA(28),
output3, X, 127, 1, Z) ," &
input, X) ," &
"71 ( BC_1, XDATA(27),
"72 ( BC_2, XDATA(27),
output3, X, 127, 1, Z) ," &
input, X) ," &
"73 ( BC_1, XDATA(26),
"74 ( BC_2, XDATA(26),
output3, X, 127, 1, Z) ," &
input, X) ," &
"75 ( BC_1, XDATA(25),
"76 ( BC_2, XDATA(25),
output3, X, 127, 1, Z) ," &
input, X) ," &
A-18
S3C4510B
APPENDIX A
"77 ( BC_1, XDATA(24),
"78 ( BC_2, XDATA(24),
output3, X, 127, 1, Z) ," &
input, X) ," &
"79 ( BC_1, XDATA(23),
"80 ( BC_2, XDATA(23),
output3, X, 127, 1, Z) ," &
input, X) ," &
"81 ( BC_1, XDATA(22),
"82 ( BC_2, XDATA(22),
output3, X, 127, 1, Z) ," &
input, X) ," &
"83 ( BC_1, XDATA(21),
"84 ( BC_2, XDATA(21),
output3, X, 127, 1, Z) ," &
input, X) ," &
"85 ( BC_1, XDATA(20),
"86 ( BC_2, XDATA(20),
output3, X, 127, 1, Z) ," &
input, X) ," &
"87 ( BC_1, XDATA(19),
"88 ( BC_2, XDATA(19),
output3, X, 127, 1, Z) ," &
input, X) ," &
"89 ( BC_1, XDATA(18),
"90 ( BC_2, XDATA(18),
output3, X, 127, 1, Z) ," &
input, X) ," &
"91 ( BC_1, XDATA(17),
"92 ( BC_2, XDATA(17),
output3, X, 127, 1, Z) ," &
input, X) ," &
"93 ( BC_1, XDATA(16),
"94 ( BC_2, XDATA(16),
output3, X, 127, 1, Z) ," &
input, X) ," &
"95 ( BC_1, XDATA(15),
"96 ( BC_2, XDATA(15),
output3, X, 127, 1, Z) ," &
input, X) ," &
"97 ( BC_1, XDATA(14),
"98 ( BC_2, XDATA(14),
output3, X, 127, 1, Z) ," &
input, X) ," &
"99 ( BC_1, XDATA(13),
"100 ( BC_2, XDATA(13),
output3, X, 127, 1, Z) ," &
input, X) ," &
"101 ( BC_1, XDATA(12),
"102 ( BC_2, XDATA(12),
output3, X, 127, 1, Z) ," &
input, X) ," &
"103 ( BC_1, XDATA(11),
"104 ( BC_2, XDATA(11),
output3, X, 127, 1, Z) ," &
input, X) ," &
"105 ( BC_1, XDATA(10),
"106 ( BC_2, XDATA(10),
output3, X, 127, 1, Z) ," &
input, X) ," &
"107 ( BC_1, XDATA(9),
"108 ( BC_2, XDATA(9),
output3, X, 127, 1, Z) ," &
input, X) ," &
"109 ( BC_1, XDATA(8),
output3, X, 127, 1, Z) ," &
A-19
APPENDIX A
S3C4510B
"110 ( BC_2, XDATA(8),
input, X) ," &
"111 ( BC_1, XDATA(7),
"112 ( BC_2, XDATA(7),
output3, X, 127, 1, Z) ," &
input, X) ," &
"113 ( BC_1, XDATA(6),
"114 ( BC_2, XDATA(6),
output3, X, 127, 1, Z) ," &
input, X) ," &
"115 ( BC_1, XDATA(5),
"116 ( BC_2, XDATA(5),
output3, X, 127, 1, Z) ," &
input, X) ," &
"117 ( BC_1, XDATA(4),
"118 ( BC_2, XDATA(4),
output3, X, 127, 1, Z) ," &
input, X) ," &
"119 ( BC_1, XDATA(3),
"120 ( BC_2, XDATA(3),
output3, X, 127, 1, Z) ," &
input, X) ," &
"121 ( BC_1, XDATA(2),
"122 ( BC_2, XDATA(2),
output3, X, 127, 1, Z) ," &
input, X) ," &
"123 ( BC_1, XDATA(1),
"124 ( BC_2, XDATA(1),
output3, X, 127, 1, Z) ," &
input, X) ," &
"125 ( BC_1, XDATA(0),
"126 ( BC_2, XDATA(0),
output3, X, 127, 1, Z) ," &
input, X) ," &
"127 ( BC_1, *,
controlr, 1) ," & --DATAOUT_ENB
"128 ( BC_1, ADDR(21),
"129 ( BC_1, ADDR(20),
"130 ( BC_1, ADDR(19),
"131 ( BC_1, ADDR(18),
"132 ( BC_1, ADDR(17),
"133 ( BC_1, ADDR(16),
"134 ( BC_1, ADDR(15),
"135 ( BC_1, ADDR(14),
"136 ( BC_1, ADDR(13),
"137 ( BC_1, ADDR(12),
"138 ( BC_1, ADDR(11),
"139 ( BC_1, ADDR(10),
"140 ( BC_1, ADDR(9),
"141 ( BC_1, ADDR(8),
"142 ( BC_1, ADDR(7),
"143 ( BC_1, ADDR(6),
"144 ( BC_1, ADDR(5),
"145 ( BC_1, ADDR(4),
"146 ( BC_1, ADDR(3),
"147 ( BC_1, ADDR(2),
"148 ( BC_1, ADDR(1),
"149 ( BC_1, ADDR(0),
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
A-20
S3C4510B
APPENDIX A
"150 ( BC_1, ExtMACK,
"151 ( BC_2, ExtMREQ,
output2, X) ," &
input, X) ," &
"152 ( BC_1, nWBE(3),
"153 ( BC_1, nWBE(2),
"154 ( BC_1, nWBE(1),
"155 ( BC_1, nWBE(0),
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
"156 ( BC_1, nDWE,
output3, X, 184, 1, Z) ," &
"157 ( BC_1, nCAS(3),
"158 ( BC_1, nCAS(2),
"159 ( BC_1, nCAS(1),
"160 ( BC_1, nCAS(0),
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
"161 ( BC_1, nRAS(3),
"162 ( BC_1, nRAS(2),
"163 ( BC_1, nRAS(1),
"164 ( BC_1, nRAS(0),
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
"165 ( BC_1, nRCS(5),
"166 ( BC_1, nRCS(4),
"167 ( BC_1, nRCS(3),
"168 ( BC_1, nRCS(2),
"169 ( BC_1, nRCS(1),
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
"170 ( BC_2, CLKSEL,
"171 ( BC_2, nRESET,
"172 ( BC_4, MCLK,
"173 ( BC_1, MCLKO,
"174 ( BC_2, CLKOEN,
input, X) ," &
input, X) ," &
input, X) ," &
output2, X) ," &
input, X) ," &
"175 ( BC_1, nRCS(0),
output3, X, 184, 1, Z) ," &
"176 ( BC_2, B0SIZE(1),
"177 ( BC_2, B0SIZE(0),
input, X) ," &
input, X) ," &
"178 ( BC_1, nOE,
output3, X, 184, 1, Z) ," &
input, X) ," &
"179 ( BC_2, nEWAIT,
"180 ( BC_1, nECS(3),
"181 ( BC_1, nECS(2),
"182 ( BC_1, nECS(1),
"183 ( BC_1, nECS(0),
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
output3, X, 184, 1, Z) ," &
A-21
APPENDIX A
S3C4510B
"184 ( BC_1, *,
controlr, 1) ," & --DIS_BUS
"185 ( BC_2, UCLK,
"186 ( BC_2, TMODE,
input, X) ," &
input, X) ," &
"187 ( BC_1, MDC,
"188 ( BC_2, LITTLE,
output2, X) ," &
input, X) ," &
"189 ( BC_1, *,
"190 ( BC_1, MDIO,
"191 ( BC_2, MDIO,
controlr, 1) ," & --MDIO_OE
output3, X, 189, 1, Z) ," &
input, X) ," &
"192 ( BC_1, TX_EN_TXEN_10M, output2, X) ," &
"193 ( BC_2, TX_CLK_TXCLK_10M, input, X) ," &
"194 ( BC_1, TX_ERR_PCOMP_10M, output2, X) ," &
"195 ( BC_1, TXD3,
"196 ( BC_1, TXD2,
output2, X) ," &
output2, X) ," &
"197 ( BC_1, TXD1_LOOP10,
"198 ( BC_1, TXD0_TXD_10M, output2, X) ," &
"199 ( BC_2, COL_COL_10M, input, X) ," &
"200 ( BC_2, RX_CLK_RXCLK_10M, input, X) ," &
output2, X) ," &
"201 ( BC_2, RX_ERR,
"202 ( BC_2, RXD3,
"203 ( BC_2, RXD2,
"204 ( BC_2, RXD1,
input, X) ," &
input, X) ," &
input, X) ," &
input, X) ," &
"205 ( BC_2, RXD0_RXD_10M, input, X) ," &
"206 ( BC_2, RX_DV_LINK10, input, X) ," &
"207 ( BC_2, CRS_CRS_10M,
input, X) ," &
"208 ( BC_1, *,
"209 ( BC_1, TXCB,
"210 ( BC_2, TXCB,
controlr, 1) ," & --TXCBEN
output3, X, 208, 1, Z) ," &
input, X) ," &
"211 ( BC_1, nSYNCB,
"212 ( BC_2, RXCB,
"213 ( BC_2, nDCDB,
"214 ( BC_2, nCTSB,
"215 ( BC_1, TXDB,
"216 ( BC_1, nRTSB,
"217 ( BC_2, RXDB,
"218 ( BC_1, nDTRB,
output2, X) ," &
input, X) ," &
input, X) ," &
input, X) ," &
output2, X) ," &
output2, X) ," &
input, X) ," &
output2, X) ," &
"219 ( BC_1, *,
"220 ( BC_1, TXCA,
"221 ( BC_2, TXCA,
controlr, 1), " & --TXCAEN
output3, X, 219, 1, Z) ," &
input, X) ," &
A-22
S3C4510B
APPENDIX A
"222 ( BC_1, nSYNCA,
"223 ( BC_2, RXCA,
"224 ( BC_2, nDCDA,
"225 ( BC_2, nCTSA,
"226 ( BC_1, TXDA,
"227 ( BC_1, nRTSA,
"228 ( BC_2, RXDA,
"229 ( BC_1, nDTRA,
"230 ( BC_1, nUADSR1,
"231 ( BC_1, UATXD1,
"232 ( BC_2, nUADTR1,
end S3C4510B;
output2, X) ," &
input, X) ," &
input, X) ," &
input, X) ," &
output2, X) ," &
output2, X) ," &
input, X) ," &
output2, X) ," &
output2, X) ," &
output2, X) ," &
input, X) ";
A-23
APPENDIX A
S3C4510B
NOTES
A-24
相关型号：
SI9130DB
5- and 3.3-V Step-Down Synchronous ConvertersWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9135LG-T1
SMBus Multi-Output Power-Supply ControllerWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9135LG-T1-E3
SMBus Multi-Output Power-Supply ControllerWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9135_11
SMBus Multi-Output Power-Supply ControllerWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9136_11
Multi-Output Power-Supply ControllerWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9130CG-T1-E3
Pin-Programmable Dual Controller - Portable PCsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9130LG-T1-E3
Pin-Programmable Dual Controller - Portable PCsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9130_11
Pin-Programmable Dual Controller - Portable PCsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9137
Multi-Output, Sequence Selectable Power-Supply Controller for Mobile ApplicationsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9137DB
Multi-Output, Sequence Selectable Power-Supply Controller for Mobile ApplicationsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9137LG
Multi-Output, Sequence Selectable Power-Supply Controller for Mobile ApplicationsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9122E
500-kHz Half-Bridge DC/DC Controller with Integrated Secondary Synchronous Rectification DriversWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
©2020 ICPDF网 联系我们和版权申明