S8S3122X16-TCR1 [SAMSUNG]
256K x 16 SDRAM; 256K ×16 SDRAM型号: | S8S3122X16-TCR1 |
厂家: | SAMSUNG |
描述: | 256K x 16 SDRAM |
文件: | 总44页 (文件大小:1162K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
S8S3122X16
CMOS SDRAM
256K x 16 SDRAM
128K x 16bit x 2 Banks
Synchronous DRAM
LVTTL
Version 0.0
Sep 2001
Samsung Electronics reserves the right to change products or specification without notice.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
Revision History
Version 0.0 (Sep. 2001)
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
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LVTTL, 3 . 0 V, 3 . 0 V
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Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
128K x 16Bit x 2 Banks Synchronous DRAM
FEATURES
GENERAL DESCRIPTION
• 3.3V power supply
The S8S3122X16 is 4,194,304 bits synchronous high data rate
Dynamic RAM organized as 2 x131,072 words by 16 bits, fabri-
cated with SAMSUNG¢s high performance CMOS technology.
Synchronous design allows precise cycle control with the use of
system clock I/O transactions are possible on every clock cycle.
Range of operating frequencies, programmable burst length
and programmable latencies allow the same device to be useful
for a variety of high bandwidth, high performance memory sys-
tem applications.
• LVTTL compatible with multiplexed address
• Dual banks operation
• MRS cycle with address key programs
-. CAS Latency ( 2 & 3)
-. Burst Length (1, 2, 4, 8 & full page)
-. Burst Type (Sequential & Interleave)
• All inputs are sampled at the positive going edge of the system
clock
• Burst Read Single-bit Write operation
• DQM for masking
ORDERING INFORMATION
• Auto & self refresh
Part NO.
MAX Freq.
100MHz(CL2)
100MHz(CL3)
Interface Package
• 15.6us refresh duty cycle (1K/16ms)
S8S3122X16-TCR2
S8S3122X16-TCR1
50
LVTTL
TSOP(II)
FUNCTIONAL BLOCK DIAGRAM
LWE
Data Input Register
LDQM
Bank Select
128K x 16
128K x 16
DQi
CLK
ADD
Column Decoder
Latency & Burst Length
LCKE
Programming Register
LWCBR
LRAS
LCBR
LWE
LCAS
LDQM
Timing Register
CLK
CKE
CS
RAS
CAS
WE
L(U)DQM
Samsung Electronics reserves the right to
change products or specification without
notice.
*
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
PIN CONFIGURATION (TOP VIEW)
VDD
DQ0
DQ1
VSSQ
DQ2
DQ3
VDDQ
DQ4
DQ5
VSSQ
DQ6
DQ7
VDDQ
LDQM
WE
CAS
RAS
CS
BA
A8/AP
A0
A1
A2
A3
VDD
1
2
3
4
5
6
7
8
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
VSS
DQ15
DQ14
VSSQ
DQ13
DQ12
VDDQ
DQ11
DQ10
VSSQ
DQ9
DQ8
VDDQ
N.C/RFU
UDQM
CLK
CKE
N.C
N.C
N.C
A7
A6
A5
A4
VSS
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
50PIN TSOP (II)
(400mil x 825mil)
(0.8 mm PIN PITCH)
PIN FUNCTION DESCRIPTION
Pin
Name
System Clock
Input Function
CLK
CS
Active on the positive going edge to sample all inputs.
Disables or enables device operation by masking or enabling all inputs except
CLK, CKE and L(U)DQM
Chip Select
Masks system clock to freeze operation from the next clock cycle.
CKE should be enabled at least one cycle prior to new command.
Disable input buffers for power down in standby.
CKE
Clock Enable
Row / column addresses are multiplexed on the same pins.
Row address : RA0 ~ RA8, column address : CA0 ~ CA7
A0 ~ A8/AP
BA
Address
Selects bank to be activated during row address latch time.
Selects bank for read/write during column address latch time.
Bank Select Address
Row Address Strobe
Latches row addresses on the positive going edge of the CLK with RAS low.
Enables row access & precharge.
RAS
Latches column addresses on the positive going edge of the CLK with CAS low.
Enables column access.
CAS
Column Address Strobe
Write Enable
Enables write operation and row precharge.
Latches data in starting from CAS, WE active.
WE
Makes data output Hi-Z, tSHZ after the clock and masks the output.
Blocks data input when L(U)DQM active.
L(U)DQM
Data Input/Output Mask
DQ0 ~ 15
VDD/VSS
Data Input/Output
Data inputs/outputs are multiplexed on the same pins.
Power and ground for the input buffers and the core logic.
Power Supply/Ground
Isolated power supply and ground for the output buffers to provide improved noise
immunity.
VDDQ/VSSQ
N.C/RFU
Data Output Power/Ground
No Connection/
Reserved for Future Use
This pin is recommended to be left No Connection on the device.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
ABSOLUTE MAXIMUM RATINGS
Parameter
Voltage on any pin relative to Vss
Voltage on VDD supply relative to Vss
Storage temperature
Symbol
VIN, VOUT
VDD, VDDQ
TSTG
Value
-1.0 ~ 4.6
-1.0 ~ 4.6
-55 ~ +150
1
Unit
V
V
°C
W
Power dissipation
PD
Short circuit current
IOS
50
mA
Note :
Permanent device damage may occur if ABSOLUTE MAXIMUM RATINGS are exceeded.
Functional operation should be restricted to recommended operating condition.
Exposure to higher than recommended voltage for extended periods of time could affect device reliability.
DC OPERATING CONDITIONS
Recommended operating conditions (Voltage referenced to VSS = 0V, TA = 0 to 70°C)
Parameter
Supply voltage
Symbol
VDD, VDDQ
VIH
Min
3.0
2.0
-0.3
2.4
-
Typ
Max
Unit
V
Note
3.3
3.6
Input logic high votlage
Input logic low voltage
Output logic high voltage
Output logic low voltage
Input leakage current
3.0
VDDQ+0.3
V
1
VIL
0
-
0.8
-
V
2
VOH
V
IOH = -2mA
IOL = 2mA
3
VOL
-
0.4
10
V
ILI
-10
-
uA
Note :
:
1. VIH (max) = 5.6V AC. The overshoot voltage duration is £ 3ns.
2. VIL (min) = -2.0V AC. The undershoot voltage duration is £ 3ns.
3. Any input 0V £ VIN £ VDDQ.
Input leakage currents include HI-Z output leakage for all bi-directional buffers with Tri-State outputs.
CAPACITANCE (VDD = 3.3V, TA = 23°C, f = 1MHz, VREF =1.4V ± 200 mV)
Pin
Symbol
CCLK
CIN
Min
2
Max
Unit
pF
Clock
RAS, CAS, WE, CS, CKE, L(U)DQM
Address
4
4
4
5
2
pF
CADD
COUT
2
pF
DQ0 ~ DQ15
3
pF
DECOUPLING CAPACITANCE GUIDE LINE
Recommended decoupling capacitance added to power line at board.
Parameter
Symbol
CDC1
Value
Unit
uF
Decoupling Capacitance between VDD and VSS
Decoupling Capacitance between VDDQ and VSSQ
0.1 + 0.01
0.1 + 0.01
CDC2
uF
Note :
1. VDD and VDDQ pins are separated each other.
All VDD pins are connected in chip. All VDDQ pins are connected in chip.
2. VSS and VSSQ pins are separated each other
All VSS pins are connected in chip. All VSSQ pins are connected in chip.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
DC CHARACTERISTICS
(Recommended operating condition unless otherwise noted, TA = 0 to 70°C)
Version
Sym-
bol
CAS
Latency
Parameter
Test Condition
Unit Note
-TCR2 -TCR1
Burst Length =1
tRC³ tRC(min)
Io = 0 mA
3
2
100
100
90
90
Operating Current
(One Bank Active)
ICC1
mA
mA
2
ICC2P
CKE£VIL(max), tCC = 15ns
2
2
Precharge Standby Cur-
rent in power-down mode
ICC2PS CKE & CLK£VIL(max), tCC = ¥
CKE³ VIH(min), CS³ VIH(min), tCC = 15ns
Input signals are changed one time during 30ns
ICC2N
15
5
Precharge Standby Current
in non power-down mode
mA
mA
CKE³ VIH(min), CLK£VIL(max), tCC = ¥
Input signals are stable
ICC2NS
ICC3P
CKE£VIL(max), tCC = 15ns
3
3
Active Standby Current
in power-down mode
ICC3PS CKE & CLK£VIL(max), tCC = ¥
CKE³ VIH(min), CS³ VIH(min), tCC = 15ns
ICC3N
25
15
mA
mA
Active Standby Current
in non power-down mode
(One Bank Active)
Input signals are changed one time during 30ns
CKE³ VIH(min), CLK£VIL(max), tCC = ¥
ICC3NS
Input signals are stable
3
2
100
95
100
95
Io = 0 mA
Page Burst 2Banks Activated
tCCD = 2CLKs
Operating Current
(Burst Mode)
ICC4
mA
2
3
3
2
100
100
90
90
Refresh Current
ICC5
ICC6
tRC³ tRC(min)
CKE£0.2V
mA
mA
Self Refresh Current
2
Note :
1. Unless otherwise notes, Input level is CMOS(VIH/VIL=VDDQ/VSSQ) in LVTTL.
2. Measured with outputs open. Addresses are changed only one time during tcc(min).
3. Refresh period is 16ms. Addresses are changed only one time during tcc(min).
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
*2
AC OPERATING TEST CONDITIONS (VDD = 3.3V±0.3V , TA = 0 to 70°C)
Parameter
Input levels (Vih/Vil)
Value
2.4 / 0.4
1.4
Unit
V
Input timing measurement reference level
Input rise and fall time
V
tr / tf = 1 / 1
1.4
ns
V
Output timing measurement reference level
Output load condition
See Fig. 2
3.3V
Vtt=1.4V
1200W
50W
VOH (DC) = 2.4V, IOH = -2mA
VOL (DC) = 0.4V, IOL = 2mA
Output
Output
Z0=50W
50pF
50pF
870W
(Fig. 1) DC Output Load Circuit
(Fig. 2) AC Output Load Circuit
OPERATING AC PARAMETER
(AC operating conditions unless otherwise noted)
version
Symbol
Parameter
Unit
Note
-TCR2
-TCR1
CAS Latency
CLK cycle time
CL
3
2
3
2
CLK
ns
tCC(min)
10 10 10 12
2
Row active to row active delay
RAS to CAS delay
tRRD(min)
tRCD(min)
tRP(min)
CLK
CLK
CLK
CLK
us
1
1
1
1
2
2
5
2
2
5
2
2
5
2
2
4
Row precharge time
tRAS(min)
tRAS(max)
Row active time
Row cycle time
100
tRC(min)
7
7
7
6
CLK
1
Last data in to row precharge
Last data in to new col.address delay
Last data in to burst stop
tRDL(min)
tCDL(min)
tBDL(min)
tCCD(min)
tMRS(min)
1
1
1
1
2
2
1
CLK
CLK
CLK
CLK
CLK
2
2
2
Col. address to col. address delay
Mode Register Set cycle time
CAS Latency=3
CAS Latency=2
Number of valid output data
ea
4
Notes :
1. The minimum number of clock cycles is determined by dividing the minimum time required with clock cycle time and then
rounding off to the next higher integer. Refer to the following clock unit based AC conversion table
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
version
Parameter
Symbol
Unit
-TCR2
-TCR1
10
CLK cycle time
tCC(min)
10
20
20
20
48
ns
ns
ns
ns
ns
us
ns
Row active to row active delay
RAS to CAS delay
tRRD(min)
tRCD(min)
tRP(min)
20
20
Row precharge time
20
tRAS(min)
tRAS(max)
tRC(min)
48
Row active time
Row cycle time
100
70
70
2. Minimum delay is required to complete write.
3. All parts allow every cycle column address change.
4. In case of row precharge interrupt, auto precharge and read burst stop.
AC CHARACTERISTICS (AC operating conditions unless otherwise noted)
-TCR2
-TCR1
Parameter
Symbol
tCC
Unit Note
Min Max Min Max
CAS Latency=3
10
10
-
10
12
-
CLK cycle time
1000
1000 ns
1
CAS Latency=2
CAS Latency=3
CAS Latency=2
6
6
-
6
8
-
CLK to valid
output delay
tSAC
ns
1, 2
-
-
Output data
tOH
tCH
2.5
2.5
ns
ns
2
3
CAS Latency=3
CAS Latency=2
CAS Latency=3
CAS Latency=2
CAS Latency=3
CAS Latency=2
CLK high pulse width
3
3
2
-
-
-
3.5
3.5
2.5
-
-
-
CLK low pulse width
Input setup time
tCL
tSS
ns
ns
3
3
Input hold time
tSH
1
1
-
-
-
1
1
-
-
-
ns
ns
3
2
CLK to output in Low-Z
tSLZ
CAS Latency=3
CAS Latency=2
6
6
6
8
CLK to output
in Hi-Z
tSHZ
ns
-
-
Note :
1. Parameters depend on programmed CAS latency.
2. If clock rising time is longer than 1ns, (tr/2-0.5)ns should be added to the parameter.
3. Assumed input rise and fall time (tr & tf)=1ns.
If tr & tf is longer than 1ns, transient time compensation should be considered,
i.e., [(tr + tf)/2-1]ns should be added to the parameter.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
SIMPLIFIED TRUTH TABLE
CKEn-1
CKEn
CS
RAS
CAS
WE
DQM
BA
A8/AP
A7~ A0
Note
1, 2
3
COMMAND
Register
Refresh
Mode Register Set
Auto Refresh
H
X
H
L
L
L
L
L
X
OP CODE
H
L
L
L
L
H
X
X
X
X
Entry
3
Self
Refresh
L
H
L
H
X
L
H
X
H
H
X
H
3
Exit
H
3
Bank Active & Row Addr.
H
H
X
X
X
X
V
V
Row Address
Column
Address
(A0~A7)
Read &
Auto Precharge Disable
Auto Precharge Enable
Auto Precharge Disable
Auto Precharge Enable
L
4
4, 5
4
L
L
H
H
L
L
H
L
Column Address
H
Column
Address
(A0~A7)
Write &
L
H
X
X
V
Column Address
H
4, 5
6
Burst Stop
Precharge
H
H
X
X
L
L
H
L
H
H
L
L
X
X
X
Bank Selection
Both Banks
V
X
L
X
H
H
L
X
V
X
X
H
X
X
V
X
X
H
X
V
X
V
X
X
H
X
V
Entry
H
L
X
Clock Suspend or
Active Power Down
X
Exit
L
H
L
X
H
L
X
X
Entry
H
Precharge Power Down Mode
X
H
L
Exit
L
H
X
X
V
X
DQM
H
H
V
X
X
X
7
H
L
X
H
X
H
X
H
No Operation Command
(V=Valid, X=Don¢t Care, H=Logic High, L=Logic Low)
Note :
1. OP Code : Operand Code
A0 ~ A8/AP, BA : Program keys. (@MRS)
2. MRS can be issued only at both banks precharge state.
A new command can be issued after 2 clock cycle of MRS.
3. Auto refresh functions are as same as CBR refresh of DRAM.
The automatical precharge without row precharge command is meant by "Auto".
Auto/self refresh can be issued only at both banks precharge state.
4. BA : Bank select address.
If "Low" at read, write, row active and precharge, bank A is selected.
If "High" at read, write, row active and precharge, bank B is selected.
If A8/AP is "High" at row precharge, BA is ignored and both banks are selected.
5. During burst read or write with auto precharge, new read/write command can not be issued.
Another bank read/write command can be issued after the end of burst.
New row active of the assoiated bank can be issued at tRP after the end of burst.
6. Burst stop command is valid at every burst length.
7. DQM sampled at positive going edge of a CLK masks the data-in at the very CLK (Write DQM latency is 0),
but makes Hi-Z state the data-out of 2 CLK cycles after. (Read DQM latency is 2)
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
MODE REGISTER FIELD TABLE TO PROGRAM MODES
Register Programmed with MRS
Address
Function
A8/AP
A7
A6
A5
A4
A3
A2
A1
A0
BA
TM
CAS Latency
BT
Burst Length
W.B.L
Test Mode
CAS Latency
Burst Type
Burst Length
Type
A6
0
A5
0
A4
0
Latency
Reserved
-
A3
Type
A2
0
A1 A0
BT = 0
BT = 1
A8/AP
A7
0
0
1
1
Sequential
Interleave
1
0
0
1
1
Mode Register Set
Reserved
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
0
1
2
2
1
0
0
1
0
4
8
2
4
8
0
Reserved
0
0
1
1
3
1
Reserved
0
1
0
0
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Write Burst Length
Length
1
1
0
1
Reserved Reserved
Reserved
1
BA
0
1
1
0
Reserved
Full Page Reserved
1
Burst
1
1
1
1
1
Single Bit
Full Page Length : x4 (512), x8 (256), x16 (256)
POWER UP SEQUENCE
SDRAMs must be powered up and initialized in a predefined manner to prevent undefined operations.
1. Apply power and start clock. Must maintain CKE= "H", DQM= "H" and the other pins are NOP condition at the inputs.
2. Maintain stable power, stable clock and NOP input condition for a minimum of 200us.
3. Issue precharge commands for all banks of the devices.
4. Issue 2 or more auto-refresh commands.
5. Issue a mode register set command to initialize the mode register.
cf.) Sequence of 4 & 5 is regardless of the order.
The device is now ready for normal operation.
Note : 1. If BA is high during MRS cycle, "Burst Read Single Bit Write" function will be enabled.
2. RFU (Reserved for future use) should stay "0" during MRS cycle.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
BURST SEQUENCE (BURST LENGTH = 4)
Initial Address
Sequential
Interleave
A1
A0
0
0
1
1
0
1
0
1
0
1
2
3
1
2
3
0
2
3
0
1
3
0
1
2
0
1
2
3
1
0
3
2
2
3
0
1
3
2
1
0
BURST SEQUENCE (BURST LENGTH = 8)
Initial Address
Sequential
Interleave
A2
A1
A0
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
2
3
4
5
6
7
1
2
3
4
5
6
7
0
2
3
4
5
6
7
0
1
3
4
5
6
7
0
1
2
4
5
6
7
0
1
2
3
5
6
7
0
1
2
3
4
6
7
0
1
2
3
4
5
7
0
1
2
3
4
5
6
0
1
2
3
4
5
6
7
1
0
3
2
5
4
7
6
2
3
0
1
6
7
4
5
3
2
1
0
7
6
5
4
4
5
6
7
0
1
2
3
5
4
7
6
1
0
3
2
6
7
4
5
2
3
0
1
7
6
5
4
3
2
1
0
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
DEVICE OPERATIONS
CLOCK (CLK)
ADDRESS INPUTS
: In case x 4 (A0 ~ A9/AP)
The clock input is used as the reference for all SDRAM opera-
tions. All operations are synchronized to the positive going edge
of the clock. The clock transitions must be monotonic between
VIL and VIH. During operation with CKE high all inputs are
assumed to be in a valid state (low or high) for the duration of
set-up and hold time around positive edge of the clock in order
to function well Q perform and ICC specifications.
The 19 address bits are required to decode the 524,288 word
locations are multiplexed into 10 address input pins (A0 ~ A9/
AP). The 10 bit row addresses are latched along with RAS and
BA during bank activate command. The 9 bit column addresses
are latched along with CAS, WE and BA during read or write
command.
CLOCK ENABLE (CKE)
: In case x 8 (A0 ~ A9/AP)
The clock enable(CKE) gates the clock onto SDRAM. If CKE
goes low synchronously with clock (set-up and hold time are the
same as other inputs), the internal clock is suspended from the
next clock cycle and the state of output and burst address is fro-
zen as long as the CKE remains low. All other inputs are ignored
from the next clock cycle after CKE goes low. When all banks
are in the idle state and CKE goes low synchronously with clock,
the SDRAM enters the power down mode from the next clock
cycle. The SDRAM remains in the power down mode ignoring
the other inputs as long as CKE remains low. The power down
exit is synchronous as the internal clock is suspended. When
CKE goes high at least "1CLK + tSS" before the high going edge
of the clock, then the SDRAM becomes active from the same
clock edge accepting all the input commands.
The 18 address bits are required to decode the 262,144 word
locations are multiplexed into 10 address input pins (A0 ~ A9/
AP). The 10 bit row addresses are latched along with RAS and
BA during bank activate command. The 8 bit column addresses
are latched along with CAS, WE and BA during read or write
command.
: In case x 16 (A0 ~ A8/AP)
The 17 address bits are required to decode the 131,072 word
locations are multiplexed into 9 address input pins (A0 ~ A8/AP).
The 9 bit row addresses are latched along with RAS and BA dur-
ing bank activate command. The 8 bit column addresses are
latched along with CAS, WE and BA during read or write com-
mand.
BANK ADDRESS (BA)
: In case x 4
NOP and DEVICE DESELECT
When RAS, CAS and WE are high, the SDRAM performs no
operation (NOP). NOP does not initiate any new operation, but
is needed to complete operations which require more than sin-
gle clock cycle like bank activate, burst read, auto refresh, etc.
The device deselect is also a NOP and is entered by asserting
CS high. CS high disables the command decoder so that RAS,
CAS, WE and all the address inputs are ignored.
This SDRAM is organized as two independent banks of 524,288
words x 4 bits memory arrays. The BA input is latched at the
time of assertion of RAS and CAS to select the bank to be used
for the operation. The bank select BA is latched at bank active,
read, write, mode register set and precharge operations.
: In case x 8
POWER-UP
This SDRAM is organized as two independent banks of 262,144
words x 8 bits memory arrays. The BA input is latched at the
time of assertion of RAS and CAS to select the bank to be used
for the operation. The bank select BA is latched at bank active,
read, write, mode register set and precharge operations.
SDRAMs must be powered up and initialized in a pre-
defined manner to prevent undefined operations.
1. Apply power and start clock. Must maintain CKE= "H", DQM=
"H" and the other pins are NOP condition at the inputs.
2. Maintain stable power, stable clock and NOP input condition
: In case x 16
for a minimum of 200us.
This SDRAM is organized as two independent banks of 131,072
words x 16 bits memory arrays. The BA input is latched at the
time of assertion of RAS and CAS to select the bank to be used
for the operation. The bank select BA is latched at bank active,
read, write, mode register set and precharge operations.
3. Issue precharge commands for both banks of the devices.
4. Issue 2 or more auto-refresh commands.
5. Issue a mode register set command to initialize the mode reg-
ister.
cf.) Sequence of 4 & 5 is regardless of the order.
The device is now ready for normal operation.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
DEVICE OPERATIONS (Continued)
active to initiate sensing and restoring the complete row of
dynamic cells is determined by tRAS(min). Every SDRAM bank
activate command must satisfy tRAS(min) specification before a
precharge command to that active bank can be asserted. The
maximum time any bank can be in the active state is determined
by tRAS(max). The number of cycles for both tRAS(min) and
tRAS(max) can be calculated similar to tRCD specification.
MODE REGISTER SET (MRS)
The mode register stores the data for controlling the various
operating modes of SDRAM. It programs the CAS latency, burst
type, burst length, test mode and various vendor specific options
to make SDRAM useful for variety of different applications. The
default value of the mode register is not defined, therefore the
mode register must be written after power up to operate the
SDRAM. The mode register is written by asserting low on CS,
RAS, CAS and WE (The SDRAM should be in active mode with
CKE already high prior to writing the mode register). The state of
address pins A0 ~ A8/AP and BA in the same cycle as CS, RAS,
CAS and WE going low is the data written in the mode register.
Two clock cycles is required to complete the write in the mode
register. The mode register contents can be changed using the
same command and clock cycle requirements during operation
as long as all banks are in the idle state. The mode register is
divided into various fields depending on the fields of functions.
The burst length field uses A0 ~ A2, burst type uses A3, CAS
latency (read latency from column address) uses A4 ~ A6, ven-
dor specific options or test mode use A7 ~ A8/AP. The write
burst length is programmed using BA. A7 ~ A8/AP must be set to
low for normal SDRAM operation, Refer to the table for specific
codes for various burst length, burst type and CAS latencies.
BURST READ
The burst read command is used to access burst of data on con-
secutive clock cycles from an active row in an active bank. The
burst read command is issued by asserting low on CS and CAS
with WE being high on the positive edge of the clock. The bank
must be active for at least tRCD(min) before the burst read com-
mand is issued. The first output appears in CAS latency number
of clock cycles after the issue of burst read command. The burst
length, burst sequence and latency from the burst read com-
mand is determined by the mode register which is already pro-
grammed. The burst read can be initiated on any column
address of the active row. The address wraps around if the initial
address does not start from a boundary such that number of out-
puts from each I/O are equal to the burst length programmed in
the mode register. The output goes into high-impedance at the
end of the burst, unless a new burst read was initiated to keep
the data output gapless. The burst read can be terminated by
issuing another burst read or burst write in the same bank or the
other active bank or a precharge command to the same bank.
The burst stop command is valid at every page burst length.
BANK ACTIVATE
The bank activate command is used to select a random row in
an idle bank. By asserting low on RAS and CS with desired row
and bank address, a row access is initiated. The read or write
operation can occur after a time delay of tRCD(min) from the time
of bank activation. tRCD is an internal timing parameter of
SDRAM, therefore it is dependent on operating clock frequency.
The minimum number of clock cycles required between bank
activate and read or write command should be calculated by
dividing tRCD(min) with cycle time of the clock and then rounding
off the result to the next higher integer. The SDRAM has two
internal banks in the same chip and shares part of the internal
circuitry to reduce chip area, therefore it restricts the activation
of two banks simultaneously. Also the noise generated during
sensing of each bank of SDRAM is high, requiring some time for
power supplies to recover before the other bank can be sensed
reliably. tRRD(min) specifies the minimum time required between
activating different bank. The number of clock cycles required
between different bank activation must be calculated similar to
tRCD specification. The minimum time required for the bank to be
BURST WRITE
The burst write command is similar to burst read command and
is used to write data into the SDRAM on consecutive clock
cycles in adjacent addresses depending on burst length and
burst sequence. By asserting low on CS, CAS and WE with valid
column address, a write burst is initiated. The data inputs are
provided for the initial address in the same clock cycle as the
burst write command. The input buffer is deselected at the end
of the burst length, even though the internal writing can be com-
pleted yet. The writing can be completed by issuing a burst read
and DQM for blocking data inputs or burst write in the same or
another active bank. The burst stop command is valid at every
burst length. The write burst can also be terminated by using
DQM for blocking data and procreating the bank tRDL after the
last data input to be written into the active row. See DQM
OPERATION also.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
DEVICE OPERATIONS (Continued)
AUTO REFRESH
DQM OPERATION
The DQM is used to mask input and output operations. It works
similar to OE during read operation and inhibits writing during
write operation. The read latency is two cycles from DQM and
zero cycle for write, which means DQM masking occurs two
cycles later in read cycle and occurs in the same cycle during
write cycle. DQM operation is synchronous with the clock. The
DQM signal is important during burst interruptions of write with
read or precharge in the SDRAM. Due to asynchronous nature
of the internal write, the DQM operation is critical to avoid
unwanted or incomplete writes when the complete burst write is
not required. Please refer to DQM timing diagram also.
The storage cells of SDRAM need to be refreshed every 16ms
to maintain data. An auto refresh cycle accomplishes refresh of
a single row of storage cells. The internal counter increments
automatically on every auto refresh cycle to refresh all the rows.
An auto refresh command is issued by asserting low on CS,
RAS and CAS with high on CKE and WE. The auto refresh com-
mand can only be asserted with both banks being in idle state
and the device is not in power down mode (CKE is high in the
previous cycle). The time required to complete the auto refresh
operation is specified by tRFC(min). The minimum number of
clock cycles required can be calculated by driving tRFC with
clock cycle time and them rounding up to the next higher integer.
The auto refresh command must be followed by NOP's until the
auto refresh operation is completed. Both banks will be in the
idle state at the end of auto refresh operation. The auto refresh
is the preferred refresh mode when the SDRAM is being used
for normal data transactions. The auto refresh cycle can be per-
formed once in 15.6us or a burst of 1024 auto refresh cycles
once in 16ms.
PRECHARGE
The precharge operation is performed on an active bank by
asserting low on CS, RAS, WE and A8/AP with valid BA of the
bank to be precharged. The precharge command can be
asserted anytime after tRAS(min) is satisfied from the bank active
command in the desired bank. tRP is defined as the minimum
number of clock cycles required to complete row precharge is
calculated by dividing tRP with clock cycle time and rounding up
to the next higher integer. Care should be taken to make sure
that burst write is completed or DQM is used to inhibit writing
before precharge command is asserted. The maximum time any
bank can be active is specified by tRAS(max). Therefore, each
bank activate command. At the end of precharge, the bank
enters the idle state and is ready to be activated again. Entry to
Power down, Auto refresh, Self refresh and Mode register set
etc. is possible only when both banks are in idle state.
SELF REFRESH
The self refresh is another refresh mode available in the
SDRAM. The self refresh is the preferred refresh mode for data
retention and low power operation of SDRAM. In self refresh
mode, the SDRAM disables the internal clock and all the input
buffers except CKE. The refresh addressing and timing are
internally generated to reduce power consumption.
The self refresh mode is entered from both banks idle state by
asserting low on CS, RAS, CAS and CKE with high on WE.
Once the self refresh mode is entered, only CKE state being low
matters, all the other inputs including the clock are ignored in
order to remain in the self refresh mode.
AUTO PRECHARGE
The precharge operation can also be performed by using auto
precharge. The SDRAM internally generates the timing to satisfy
tRAS(min) and "tRP" for the programmed burst length and CAS
latency. The auto precharge command is issued at the same
time as burst read or burst write by asserting high on A8/AP. If
burst read or burst write by asserting high on A8/AP, the bank is
The self refresh is exited by restarting the external clock and
then asserting high on CKE. This must be followed by NOP's for
a minimum time of tRFC before the SDRAM reaches idle state to
begin normal operation. If the system uses burst auto refresh
during normal operation, it is recommended to use burst 1024
auto refresh cycles immediately after exiting in self refresh
mode.
left active until
a new command is asserted. Once auto
precahrge command is given, no new commands are possible to
that particular bank until the bank achieves idle state.
BOTH BANKS PRECHARGE
Both banks can be precharged at the same time by using pre-
charge all command. Asserting low on CS, RAS, and WE with
high on A8/AP after both banks have satisfied tRAS(min) require-
ment, performs precharge on both banks. At the end of tRP after
performing precharge to all the banks, both banks are in idle
state.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
BASIC FEATURE AND FUNCTION DESCRIPTIONS
1. CLOCK Suspend
1) Clock Suspended During Write (BL=4)
2) Clock Suspended During Read (BL=4)
CLK
CMD
CKE
WR
RD
Masked by CKE
Masked by CKE
Internal
CLK
Q1
DQ(CL2)
DQ(CL3)
D0
D0
D1
D1
D2
D2
D3
D3
Q0
Q2
Q1
Q3
Q2
Q3
Q0
Not Written
SuspendedDout
2. DQM Operation
1) Write Mask (BL=4)
2) Read Mask (BL=4)
CLK
WR
RD
CMD
DQM
Masked by DQM
Masked by DQM
Hi-Z
Hi-Z
DQ(CL2)
DQ(CL3)
D0
D0
D1
D1
D3
D3
Q0
Q2
Q1
Q3
Q2
Q3
DQM to Data-in Mask = 0
DQM to Data-out Mask = 2
3) DQM with Clock Suspended (Full Page Read) Note 2
CLK
CMD
RD
CKE
DQM
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
DQ(CL2)
DQ(CL3)
Q6
Q5
Q0
Q2
Q1
Q4
Q3
Q7
Q6
Q8
Q7
*Note : 1. CKE to CLK disable/enable = 1CLK.
2. DQM makes data out Hi-Z after 2CLKs which should masked by CKE " L"
3. DQM masks both data-in and data-out.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
3. CAS Interrupt (I)
Note 1
1) Read interrupted by Read (BL=4)
CLK
CMD
ADD
RD RD
A
B
DQ(CL2)
DQ(CL3)
QA0 QB0 QB1 QB2 QB3
QA0 QB0 QB1 QB2 QB3
tCCD
Note 2
2) Write interrupted by Write (BL=2)
CLK
3) Write interrupted by Read (BL=2)
WR RD
WR WR
CMD
tCCD
Note 2
tCCD
Note 2
A
B
A
B
ADD
DQ
DQ(CL2)
DQ(CL3)
DA0
DA0
QB0 QB1
QB0 QB1
DA0 DB0 DB1
tCDL
Note 3
tCDL
Note 3
*Note : 1. By " Interrupt", It is meant to stop burst read/write by external command before the end of burst.
By "CAS Interrupt", to stop burst read/write by CAS access ; read and write.
2. tCCD : CAS to CAS delay. (=1CLK)
3. tCDL : Last data in to new column address delay. (=1CLK)
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
4. CAS Interrupt (II) : Read Interrupted by Write & DQM
(a) CL=2, BL=4
CLK
i) CMD
DQM
DQ
ii) CMD
RD WR
D0
D1
D2
D3
D2
RD
WR
DQM
DQ
Hi-Z
D0
D1
D3
RD
WR
iii) CMD
DQM
DQ
Hi-Z
D0
D1
D2
D1
D3
D2
RD
WR
iv) CMD
DQM
DQ
Hi-Z
Q0
D0
D3
Note 1
(b) CL=3, BL=4
CLK
i) CMD
RD WR
DQM
DQ
D0
D1
D2
D3
D2
ii) CMD
RD
WR
DQM
DQ
D0
D1
D3
D2
RD
RD
WR
iii) CMD
DQM
DQ
D0
D1
D3
WR
iii) CMD
DQM
DQ
Hi-Z
D0
D1
D2
D1
D3
D2
RD
WR
iv) CMD
DQM
DQ
Hi-Z
D0
D3
Q0
Note 1
*Note : 1. To prevent bus contention, there should be at least one gap between data in and data out.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
5. Write Interrupted by Precharge & DQM
CLK
Note 3
Note 2
WR
D0
PRE
D3
CMD
DQM
DQ
D1
D2
Masked by DQM
*Note : 2. To inhibit invalid write, DQM should be issued.
3. This precharge command and burst write command should be of the same bank, otherwise it is not precharge
interrupt but only the other bank precharge of dual banks operation.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
6. Precharge
1) Normal Write (BL=4)
CLK
WR
D0
PRE
CMD
DQ
D1
D2
D3
tRDL
Note 2
2) Normal Read (BL=4)
CLK
CMD
RD
PRE
1
DQ(CL2)
DQ(CL3)
Q0
Q1
Q0
Q2
Q1
Q3
Q2
Note 2
Q3
2
7. Auto Precharge
1) Normal Write (BL=4)
CLK
WR
D0
CMD
DQ
D1
D2
D3
Note 3
Auto Precharge Starts
2) Normal Read (BL=4)
CLK
CMD
RD
DQ(CL2)
DQ(CL3)
Q0
Q1
Q0
Q2
Q1
Q3
Q2
Q3
Note 3
Auto Precharge Starts
*Note : 1. tRDL : Last data in to row precharge delay
2. Number of valid output data after row precharge : 1, 2 for CAS Latency =2, 3 respectively.
3. The row active command of the precharge bank can be issued after tRP from this point.
The new read/write command of the other activated bank can be issued from this point.
At burst read/write with auto precharge, CAS interrupt of the same/other bank is illegal.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
8. Burst Stop & Interrupted by Precharge
1) Normal Write (BL=4)
CLK
2) Write Burst Stop (BL=8)
CLK
WR
STOP
CMD
DQM
DQ
WR
PRE
D3
CMD
DQM
DQ
D0
D1
D2
D0
D1
D2
D3
D4
D5
tRDL Note 1
tBDL Note 2
3) Read Interrupted by Precharge (BL=4)
CLK
4) Read Burst Stop (BL=4)
CLK
CMD
DQ(CL2)
DQ(CL3)
RD
PRE
Q0
CMD
RD
STOP
Q0
1
1
Q1
Q0
DQ(CL2)
DQ(CL3)
Q1
Q0
Note 3
Note 3
2
2
Q1
Q1
9. MRS
1) Mode Register Set
CLK
Note 4
CMD
MRS
ACT
PRE
tRP
tMRS = 2CLK
*Note : 1. tRDL : 1 CLK
2. tBDL : 1 CLK ; Last data in to burst stop delay.
Read or write burst stop command is valid at every burst length.
3. Number of valid output data after row precharge or burst stop : 1, 2 for CAS latency= 2, 3 respectiviely.
4. PRE : Both banks precharge if necessary.
MRS can be issued only at both banks precharge state.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
10. Clock Suspend Exit & Power Down Exit
1) Clock Suspend (=Active Power Down) Exit
CLK
2) Power Down (=Precharge Power Down)
CLK
CKE
CKE
tSS
tSS
Internal
CLK
Note 1
Internal
CLK
Note 2
CMD
CMD
ACT
NOP
RD
11. Auto Refresh & Self Refresh
Note 3
1) Auto Refresh & Self Refresh
CLK
¡ó
¡ó
Note 4
Note 5
CMD
CKE
PRE
AR
CMD
¡ó
¡ó
tRP
tRFC
Note 6
2) Self Refresh
CLK
¡ó
¡ó
Note 4
CMD
CKE
PRE
SR
CMD
¡ó
tRP
tRFC
*Note : 1. Active power down : one or both banks active state.
2. Precharge power down : both banks precharge state.
3. The auto refresh is the same as CBR refresh of conventional DRAM.
No precharge commands are required after auto refresh command.
During tRFC from auto refresh command, any other command can not be accepted.
4. Before executing auto/self refresh command, both banks must be idle state.
5. MRS, Bank Active, Auto/Self Refresh, Power Down Mode Entry.
6. During self refresh mode, refresh interval and refresh operation are perfomed internally.
After self refresh entry, self refresh mode is kept while CKE is low.
During self refresh mode, all inputs expect CKE will be don't cared, and outputs will be in Hi-Z state.
For the time interval of tRFC from self refresh exit command, any other command can not be accepted. Before/After self refresh mode, burst
auto refresh cycle (1024 cycles) is recommended.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
12. About Burst Type Control
At MRS A3 = "0". See the BURST SEQUENCE TABLE. (BL=4,8)
BL=1, 2, 4, 8 and full page.At Full page wrap-around.
Sequential Counting
Basic
MODE
At MRS A3 = "1". See the BURST SEQUENCE TABLE. (BL=4,8)
BL=4, 8. At BL=1, 2 Interleave Counting = Sequential Counting
Interleave Counting
Every cycle Read/Write Command with random column address can realize
Random Column Access.
That is similar to Extended Data Out (EDO) Operation of conventional DRAM.
Random
MODE
Random column Access
tCCD = 1 CLK
13. About Burst Length Control
At MRS A2,1,0 = "000".
At auto precharge, tRAS should not be violated.
1
At MRS A2,1,0 = "001".
At auto precharge, tRAS should not be violated.
2
Basic
MODE
4
At MRS A2,1,0 = "010".
At MRS A2,1,0 = "011".
8
At MRS A2,1,0 = "111".
Full Page
Wrap around mode(Infinite burst length)should be stopped by burst stop,
RAS interrupt or CAS interrupt.
At MRS BA = "1".
Read burst=1,2,4,8,full page Write burst=1
At auto precharge of write, tRAS should not be violate
Special
BRSW
MODE
tBDL= 1, Valid DQ after burst stop is 1, 2 for CAS latency 2, 3 respectively
Using burst stop command, any burst length control is possible.
Random
Burst Stop
MODE
Before the end of burst, Row precharge command of the same bank stops read/write
burst with Row precharge.
RAS Interrupt
tRDL= 1 with DQM, valid DQ after burst stop is 1, 2 for CAS latency 2, 3 respectively.
During read/write burst with auto precharge, RAS interrupt can not be issued.
(Interrupted by Precharge)
Interrupt
MODE
Before the end of burst, new read/write stops read/write burst and starts new
read/write burst.
CAS Interrupt
During read/write burst with auto precharge, CAS interrupt can not be issued.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
FUNCTION TRUTH TABLE (TABLE 1)
Current
State
CS
RAS
CAS
WE
BA
ADDR
ACTION
Note
H
L
L
L
L
L
L
L
H
L
L
L
L
L
L
L
H
L
L
L
L
L
L
L
H
L
L
L
L
L
L
L
H
L
L
L
L
L
H
L
L
L
L
L
H
L
L
L
L
L
X
H
H
H
L
X
H
H
L
X
H
L
X
X
X
NOP
X
NOP
X
X
ILLEGAL
ILLEGAL
2
2
X
H
L
BA
BA
BA
X
CA, A8/AP
IDLE
H
H
L
RA
Row (& Bank) Active ; Latch RA
L
A8/AP
NOP
4
5
5
L
H
L
X
Auto Refresh or Self Refresh
L
L
OP code
X
OP code
Mode Register Access
X
H
H
H
H
L
X
H
H
L
X
H
L
X
NOP
X
X
NOP
X
X
ILLEGAL
2
H
L
BA
BA
BA
BA
X
CA, A8/AP
Begin Read ; latch CA ; determine AP
Begin Write ; latch CA ; determine AP
ILLEGAL
Row
Active
L
CA, A8/AP
H
H
L
H
L
RA
2
L
A8/AP
Precharge
L
X
X
H
L
X
ILLEGAL
X
H
H
H
H
L
X
H
H
L
X
X
NOP (Continue Burst to End --> Row Active)
NOP (Continue Burst to End --> Row Active)
Term burst --> Row active
Term burst, New Read, Determine AP
Term burst, New Write, Determine AP
ILLEGAL
X
X
X
X
H
L
BA
BA
BA
BA
X
CA, A8/AP
Read
L
CA, A8/AP
3
2
H
H
L
H
L
RA
L
A8/AP
Term burst, Precharge timing for Reads
ILLEGAL
L
X
X
H
L
X
X
H
H
H
H
L
X
H
H
L
X
X
NOP (Continue Burst to End --> Row Active)
NOP (Continue Burst to End --> Row Active)
Term burst --> Row active
Term burst, New read, Determine AP
Term burst, New Write, Determine AP
ILLEGAL
X
X
X
X
H
L
BA
BA
BA
BA
X
CA, A8/AP
3
3
2
3
Write
L
CA, A8/AP
H
H
L
H
L
RA
L
A8/AP
Term burst, precharge timing for Writes
ILLEGAL
L
X
X
H
L
X
X
H
H
H
L
X
H
H
L
X
X
NOP (Continue Burst to End --> Precharge)
NOP (Continue Burst to End --> Precharge)
ILLEGAL
X
X
Read with
Auto
Precharge
X
X
X
X
X
X
H
L
BA
BA
X
CA, A8/AP
ILLEGAL
H
L
RA, RA8
ILLEGAL
2
2
L
X
ILLEGAL
X
H
H
H
L
X
H
H
L
X
X
NOP (Continue Burst to End --> Precharge)
NOP (Continue Burst to End --> Precharge)
ILLEGAL
X
X
Write with
Auto
Precharge
X
X
X
X
X
X
H
L
BA
BA
X
CA, A8/AP
ILLEGAL
H
L
RA, RA8
ILLEGAL
L
X
X
ILLEGAL
X
H
H
H
L
X
H
H
L
X
NOP --> Idle after tRP
X
X
NOP --> Idle after tRP
Pre-
charging
X
X
ILLEGAL
2
2
2
4
X
H
L
BA
BA
BA
CA
RA
A8/AP
ILLEGAL
H
H
ILLEGAL
L
NOP --> Idle after tRP
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
FUNCTION TRUTH TABLE (TABLE 1)
Current
State
CS
RAS
CAS
WE
BA
ADDR
ACTION
Note
L
H
L
L
L
L
L
L
H
L
L
L
L
H
L
L
L
L
L
X
H
H
H
L
L
X
H
H
L
X
X
H
L
X
X
X
X
ILLEGAL
NOP --> Row Active after tRCD
NOP --> Row Active after tRCD
ILLEGAL
X
X
Row
Activating
X
X
2
2
2
2
X
H
L
BA
BA
BA
X
CA
RA
A8/AP
X
ILLEGAL
H
H
L
ILLEGAL
L
ILLEGAL
L
X
X
X
X
X
X
X
H
L
ILLEGAL
X
H
H
L
X
H
L
X
X
NOP --> Idle after tRFC
NOP --> Idle after tRFC
ILLEGAL
X
X
Refreshing
X
X
H
L
X
X
ILLEGAL
L
X
X
ILLEGAL
X
H
H
H
L
X
H
H
L
X
X
NOP --> Idle after 2 clocks
NOP --> Idle after 2 clocks
ILLEGAL
X
X
Mode
Register
Accessing
X
X
X
X
X
X
ILLEGAL
X
X
X
ILLEGAL
Abbreviations : RA = Row Address
NOP = No Operation Command
BA = Bank Address
CA = Column Address
AP = Auto Precharge
*Note : 1. All entries assume the CKE was active (High) during the precharge clock and the current clock cycle.
2. Illegal to bank in specified state ; Function may be Iegal in the bank indicated by BA, depending on the
state of that bank.
3. Must satisfy bus contention, bus turn around, and/or write recovery requirements.
4. NOP to bank precharging or in idle state. May precharge bank indicated by BA (and A8/AP).
5. Illegal if any bank is not idle.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
FUNCTION TRUTH TABLE (TABLE 2)
CKE
n
CKE
(n-1)
Current
State
CS
RAS
CAS
WE
ADDR
ACTION
Note
H
L
X
H
H
H
H
H
L
X
H
L
X
X
H
H
H
L
X
X
H
H
L
X
X
H
L
X
INVALID
X
Exit Self Refresh --> Idle after tRFC (ABI)
Exit Self Refresh --> Idle after tRFC (ABI)
ILLEGAL
6
6
L
X
Self
Refresh
L
L
X
L
L
X
X
X
X
X
H
L
X
ILLEGAL
L
L
X
X
X
X
H
H
L
X
ILLEGAL
L
X
X
H
L
X
X
X
H
H
H
L
X
NOP (Maintain Self Refresh)
INVALID
H
L
X
H
H
H
H
H
L
X
X
Exit Power Down --> ABI
Exit Power Down --> ABI
ILLEGAL
All
Banks
Precharge
Power
L
X
7
7
L
L
X
L
L
X
X
X
X
X
H
L
X
ILLEGAL
Down
L
L
X
X
X
X
H
H
L
X
ILLEGAL
L
X
X
H
L
X
X
X
H
H
H
L
X
NOP (Maintain Low Power Mode)
Refer to Table 1
H
H
H
H
H
H
H
H
L
H
L
X
X
Enter Power Down
Enter Power Down
ILLEGAL
L
X
8
8
L
L
X
All
Banks
Idle
L
L
X
H
H
L
X
ILLEGAL
L
L
H
L
RA
Row (& Bank) Active
Enter Self Refresh
Mode Register Access
NOP
L
L
L
X
8
L
L
L
L
OP Code
L
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
H
H
L
H
L
Refer to Operations in Table 1
Begin Clock Suspend next cycle
Exit Clock Suspend next cycle
Maintain Clcok Suspend
Any State
other than
Listed
9
9
H
L
above
L
Abbreviations : ABI = All Banks Idle, RA = Row Address
*Note : 6. CKE low to high transition is asynchronous.
7. CKE low to high transition is asynchronous if restarts internal clock.
A minimum setup time 1CLK + tSS must be satisfied before any command other than exit.
8. Power down and self refresh can be entered only from the both banks idle state.
9. Must be a legal command.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
Single Bit Read-Write-Read Cycle(Same Page) @CAS Latency=3, Burst Length=1
tCH
1
2
3
10
4
5
6
7
8
0
9
11
12
13
14
15
16
17
18
19
CLOCK
tCL
tCC
HIGH
CKE
CS
tRAS
tRC
tSH
*Note 1
tRP
tRCD
tSS
tSH
tSS
RAS
CAS
ADDR
BA
tCCD
tSH
tSS
tSS
tSH
Ra
Ca
Cb
tSH
Cc
Rb
tSS
*Note 2
*Note 2,3
*Note 2,3
*Note 2,3 *Note 4
*Note 2
BS
BS
BS
BS
BS
BS
*Note 3
*Note 3
*Note 3 *Note 4
Ra
A8/AP
DQ
Rb
tRAC
tSH
tSAC
tSLZ
Qa
tOH
Db
Qc
tSS
tSH
WE
tSS
tSS
tSH
DQM
Row Active
Read
Write
Read
Row Active
Precharge
: Don't care
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
*Note : 1. All inputs expect CKE & DQM can be don ¡Ç t care when CS is high at the CLK high going edge.
2. Bank active & read/write are controlled by BA.
BA
0
Active & Read/Write
Bank A
1
Bank B
3. Enable and disable auto precharge function are controlled by A8/AP in read/write command.
A8/AP BA
Operation
0
Disable auto precharge, leave bank A active at end of burst.
Disable auto precharge, leave bank B active at end of burst.
Enable auto precharge, precharge bank A at end of burst.
Enable auto precharge, precharge bank B at end of burst.
0
1
0
1
1
4. A8/AP and BA control bank precharge when precharge command is asserted.
BA
0
Precharge
Bank A
A8/AP
0
0
1
1
Bank B
X
Both Banks
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
Power Up Sequence
1
2
3
10
4
5
6
7
8
0
9
11
12
13
14
15
16
17
18
19
CLOCK
High level is necessary
CKE
CS
tRC
tRP
tRC
RAS
CAS
Key
RAa
ADDR
BA
RAa
A8/AP
High-Z
DQ
WE
DQM
High level is necessary
Precharge
(All Banks)
Auto Refresh
Auto Refresh
Mode Register Set
Row Active
(A-Bank)
: Don't care
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
Read & Write Cycle at Same Bank @Burst Length=4
1
2
3
10
4
5
6
7
8
0
9
11
12
13
14
15
16
17
18
19
CLOCK
CKE
HIGH
*Note 1
tRC
CS
tRCD
RAS
CAS
*Note 2
Ra
Ca0
Rb
Cb0
ADDR
BA
Ra
Rb
A8/AP
tOH
Qa0 Qa1 Qa2 Qa3
Db0 Db1 Db2 Db3
CL=2
DQ
tRAC
tRDL
tRDL
*Note 4
tSAC
tSHZ
*Note 3
tOH
Qa0 Qa1 Qa2 Qa3
CL=3
WE
Db0 Db1 Db2 Db3
tRAC
*Note 3
tSAC
*Note 4
tSHZ
DQM
Row Active
(A-Bank)
Read
(A-Bank)
Precharge
(A-Bank)
Row Active
(A-Bank)
Write
(A-Bank)
Precharge
(A-Bank)
: Don't care
*Note : 1. Minimum row cycle times is required to complete internal DRAM operation.
2. Row precharge can interrupt burst on any cycle. [CAS Latency - 1] number of valid output data
is available after Row precharge. Last valid output will be Hi-Z(tSHZ) after the clcok.
3. Access time from Row active command. tCC *(tRCD + CAS latency - 1) + tSAC
4. Ouput will be Hi-Z after the end of burst. (1, 2, 4, 8 & Full page bit burst wrap-around).
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
Page Read & Write Cycle at Same Bank @Burst Length=4
1
2
3
10
4
5
6
7
8
0
9
11
12
13
14
15
16
17
18
19
CLOCK
CKE
HIGH
CS
tRCD
RAS
CAS
*Note 2
Ra
Ca0
Cb0
Cc0
Cd0
ADDR
BA
Ra
A8/AP
tRDL
Qa0 Qa1 Qb0 Qb1 Qb2
Qa0 Qa1 Qb0 Qb1
Dc0 Dc1 Dd0 Dd1
DQ
CL=2
CL=3
Dc0 Dc1 Dd0 Dd1
tCDL
WE
*Note 1
*Note 3
DQM
Row Active
(A-Bank)
Read
(A-Bank)
Read
(A-Bank)
Write
(A-Bank)
Write
(A-Bank)
Precharge
(A-Bank)
: Don't care
*Note : 1. To write data before burst read ends, DQM should be asserted three cycle prior to write
command to avoid bus contention.
2. Row precharge will interrupt writing. Last data input, tRDL before Row precharge, will be written.
3. DQM should mask invalid input data on precharge command cycle when asserting precharge
before end of burst. Input data after Row precharge cycle will be masked internally.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
Page Read Cycle at Different Bank @Burst Length=4
1
2
3
10
4
5
6
7
8
0
9
11
12
13
14
15
16
17
18
19
CLOCK
CKE
HIGH
*Note 1
CS
RAS
CAS
*Note 2
CAc
CAe
RAa
CAa RBb
CBb
CBd
ADDR
BA
RAa
RBb
A8/AP
QAa0 QAa1 QAa2 QAa3 QBb0 QBb1 QBb2 QBb3 QAc0 QAc1 QBd0 QBd1 QAe0 QAe1
DQ CL=2
CL=3
QAa0 QAa1 QAa2 QAa3 QBb0 QBb1 QBb2 QBb3 QAc0 QAc1 QBd0 QBd1 QAe0 QAe1
WE
DQM
Row Active
(A-Bank)
Row Active
(B-Bank)
Read
(B-Bank)
Read
(A-Bank)
Read
(B-Bank)
Read
(A-Bank)
Precharge
(A-Bank)
Read
(A-Bank)
: Don't care
*Note : 1. CS can be don't cared when RAS, CAS and WE are high at the clock high going dege.
2. To interrupt a burst read by row precharge, both the read and the precharge banks must be the same.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
Page Write Cycle at Different Bank @Burst Length=4
1
2
3
10
4
5
6
7
8
0
9
11
12
13
14
15
16
17
18
19
CLOCK
CKE
HIGH
CS
RAS
*Note 2
CAS
ADDR
BA
RAa
CAa RBb
CBb
CAc
CBd
RAa
RBb
A8/AP
DQ
DAa0 DAa1 DAa2 DAa3 DBb0 DBb1 DBb2 DBb3 DAc0 DAc1 DBd0 DBd1
tCDL
tRDL
WE
*Note 1
DQM
Row Active
(A-Bank)
Row Active
(B-Bank)
Write
(B-Bank)
Write
(A-Bank)
Precharge
(Both Banks)
Write
(A-Bank)
Write
(B-Bank)
: Don't care
*Note : 1. To interrupt burst write by Row precharge, DQM should be asserted to mask invalid input data.
2. To interrupt burst write by Row precharge, both the write and the precharge banks must be the same.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
Read & Write Cycle at Different Bank @Burst Length=4
1
2
3
10
4
5
6
7
8
0
9
11
12
13
14
15
16
17
18
19
CLOCK
CKE
HIGH
CS
RAS
CAS
ADDR
BA
RAa
RAa
CAa
RBb
RBb
CBb RAc
CAc
RAc
A8/AP
*Note 1
tCDL
DBb0 DBb1 DBb2 DBb3
QAc0 QAc1 QAc2
QAc0 QAc1
QAa0 QAa1 QAa2 QAa3
DQ CL=2
CL=3
QAa0 QAa1 QAa2 QAa3
DBb0 DBb1 DBb2 DBb3
WE
DQM
Row Active
(A-Bank)
Read
(A-Bank)
Precharge
(A-Bank)
Write
(B-Bank)
Read
(A-Bank)
Row Active
(B-Bank)
Row Active
(A-Bank)
: Don't care
*Note : 1. tCDL should be met to complete write.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
Read & Write Cycle with Auto Precharge I @Burst Length=4
1
2
3
10
4
5
6
7
8
0
9
11
12
13
14
15
16
17
18
19
CLOCK
CKE
HIGH
CS
RAS
CAS
ADDR
BA
Ra
Rb
Ca
Ra
Ca
Cb
A8/AP
Ra
Rb
Ra
Qb3
Da0
Da0
Da1
Da1
Qa0
Qa1
Qb0
Qb1
Qb0
Qb2
DQ CL=2
Qa0
Qa1
Qb1 Qb2
Qb3
CL=3
WE
DQM
Read without Auto
precharge(B-Bank)
Auto Precharge
Start Point
Write with
Auto Precharge
(A-Bank)
Read with
Auto Pre
charge
Row Active
(A-Bank)
Row Active
(A-Bank)
Precharge
(B-Bank)
(A-Bank)
(A-Bank)*
Row Active
(B-Bank)
: Don't care
*Note:
* When Read(Write) command with auto precharge is issued at A-Bank after A and B Bank activation.
- if Read(Write) command without auto precharge is issued at B-Bank before A Bank auto precharge starts, A Bank
auto precharge will start at B Bank read command input point .
- any command can not be issued at A Bank during tRP after A Bank auto precharge starts.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
Read & Write Cycle with Auto Precharge II @Burst Length=4
1
2
3
10
4
5
6
7
8
0
9
11
12
13
14
15
16
17
18
19
CLOCK
CKE
HIGH
CS
RAS
CAS
ADDR
BA
Ra
Ca
Cb
Rb
A8/AP
Rb
Ra
Qa0
Qa1
Qa2
Qa3
Qa2
Qb0
Qb1
Qb2
Qb3
DQ CL=2
Qa0
Qa1
Qa3
Qb0
Qb1
Qb2
Qb3
CL=3
WE
DQM
*
Read with
Auto Precharge
(A-Bank)
Auto Precharge
Start Point
(A-Bank)
Row Active
(A-Bank)
Read with
Auto Precharge
(B-Bank)
Auto Precharge
Start Point
(B-Bank)
Row Active
(B-Bank)
: Don't care
*Note :
*
Any command to A-bank is not allowed in this period.
tRP is determined from at auto precharge start point
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
Clock Suspension & DQM Operation Cycle @CAS Latency=2, Burst Length=4
1
2
3
10
4
5
6
7
8
0
9
11
12
13
14
15
16
17
18
19
CLOCK
CKE
CS
RAS
CAS
ADDR
Ra
Ca
Cb
Cc
BA
A8/AP
DQ
Ra
Qb0 Qb1
tSHZ
Dc0
Dc2
Qa0 Qa1
Qa2
Qa3
tSHZ
WE
*Note 1
DQM
Row Active
Read
Clock
Suspension
Read
Write
DQM
Write
DQM
Read DQM
Write
Clock
Suspension
: Don't care
*Note : 1. DQM is needed to prevent bus contention.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
Read Interrupted by Precharge Command & Read Burst Stop Cycle @Burst Length=Full page
1
2
3
10
4
5
6
7
8
0
9
11
12
13
14
15
16
17
18
19
CLOCK
CKE
HIGH
CS
RAS
CAS
RAa
CAa
CAb
ADDR
BA
A8/AP
RAa
1
1
QAa0 QAa1 QAa2 QAa3 QAa4
QAb0 QAb1 QAb2 QAb3 QAb4 QAb5
DQ
CL=2
CL=3
*Note 2
2
2
QAb0 QAb1 QAb2 QAb3 QAb4 QAb5
QAa0 QAa1 QAa2 QAa3 QAa4
WE
DQM
Row Active
(A-Bank)
Read
(A-Bank)
Burst Stop
Read
(A-Bank)
Precharge
(A-Bank)
: Don't care
*Note :
1. At full page mode, burst is wrap-around at the end of burst. So auto precharge is impossible.
2. About the valid DQs after burst stop, it is same as the case of RAS interrupt.
Both cases are illustrated above timing diagram. See the label 0. 1, 2 on them.
But at burst write, Burst stop and RAS interrupt should be compared carefully.
Refer the timing diagram of "Full page write burst stop cycle".
3. Burst stop is valid at every burst length.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
Write Interrupted by Precharge Command & Write Burst Stop Cycle @ Burst Length=Full page
1
2
3
10
4
5
6
7
8
0
9
11
12
13
14
15
16
17
18
19
CLOCK
CKE
HIGH
CS
RAS
CAS
RAa
CAa
CAb
ADDR
BA
A8/AP
DQ
RAa
tBDL
tRDL
*Note 2
DAb0 DAb1 DAb2 DAb3 DAb4 DAb5
DAa0 DAa1 DAa2 DAa3 DAa4
WE
DQM
Row Active
(A-Bank)
Write
(A-Bank)
Burst Stop
Write
(A-Bank)
Precharge
(A-Bank)
: Don't care
*Note : 1. At full page mode, burst is wrap-around at the end of burst. So auto precharge is impossible.
2. Data-in at the cycle of interrupted by precharge can not be written into the corresponding
memory cell. It is defined by AC parameter of tRDL.
DQM at write interrupted by precharge command is needed to prevent invalid write.
DQM should mask invalid input data on precharge command cycle when asserting precharge
before end of burst. Input data after Row precharge cycle will be masked internally.
3. Burst stop is valid at every burst length.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
Burst Read Single bit Write Cycle @Burst Length=2
1
2
3
10
4
5
6
7
8
0
9
11
12
13
14
15
16
17
18
19
CLOCK
CKE
*Note 1
HIGH
CS
RAS
*Note 2
CAS
RAa
CAa RBb CAb
RAc
CBc
CAd
ADDR
BA
RAa
RBb
RAc
A8/AP
DAa0
QAb0 QAb1
DBc0
DBc0
QAd0 QAd1
DQ CL=2
DAa0
QAb0 QAb1
QAd0 QAd1
CL=3
WE
DQM
Row Active
(A-Bank)
Row Active
(B-Bank)
Row Active
(A-Bank)
Read
(A-Bank)
Precharge
(A-Bank)
Write
(A-Bank)
Write with
Auto Precharge
(B-Bank)
Read with
Auto Precharge
(A-Bank)
: Don't care
*Note : 1. BRSW modes is enabled by setting BA "High" at MRS (Mode Register Set).
At the BRSW Mode, the burst length at write is fixed to "1" regaredless of programmed burst length.
2. When BRSW write command with auto precharge is executed, keep it in mind that tRAS should not be violated.
Auto precharge is executed at the burst-end cycle, so in the case of BRSW write command,
the next cycle starts the precharge.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
Active/Precharge Power Down Mode @CAS Latency=2, Burst Length=4
1
2
3
10
4
5
6
7
8
0
9
11
12
13
14
15
16
17
18
19
CLOCK
CKE
tSS
*Note 1
tSS
*Note 2
tSS
*Note 2
*Note 3
CS
RAS
CAS
Ra
Ca
ADDR
BA
Ra
A8/AP
DQ
tSHZ
Qa0
Qa2
Qa1
WE
DQM
Precharge
Power-down
Entry
Row Active
Read
Precharge
Active
Power-down
Exit
Precharge
Power-down
Exit
Active
Power-down
Entry
: Don't care
*Note : 1. Both banks should be in idle state prior to entering precharge power down mode.
2. CKE should be set high at least 1CLK + tss prior to Row active command.
3. Can not violate minimum refresh specification. (16ms)
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
Self Refresh Entry & Exit Cycle
1
2
3
10
4
5
6
7
8
0
9
11
12
13
14
15
16
17
18
19
CLOCK
CKE
*Note 4
*Note 2
tRCmin
*Note 6
*Note 1
*Note 3
tSS
*Note 5
CS
RAS
*Note 7
CAS
ADDR
BA
A8/AP
DQ
Hi-Z
Hi-Z
WE
DQM
Self Refresh Entry
Self Refresh Exit
Auto Refresh
: Don't care
*Note : TO ENTER SELF REFRESH MODE
1. CS, RAS & CAS with CKE should be low at the same clcok cycle.
2. After 1 clock cycle, all the inputs including the system clock can be don't care except for CKE.
3. The device remains in self refresh mode as long as CKE stays "Low".
cf.) Once the device enters self refresh mode, minimum tRAS is required before exit from self refresh.
TO EXIT SELF REFRESH MODE
4. System colck restart and be stable before returning CKE high.
5. CS starts from high.
6. Minimum tRC is required after CKE going high to complete self refresh exit.
7.1K cycle of burst auto refresh is required before self refresh entry and after self refresh exit if the system uses burst refresh.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
Mode Register Set Cycle
Auto Refresh Cycle
0
1
2
3
4
5
6
7
8
9
10
1
2
3
4
5
6
0
CLOCK
CKE
HIGH
HIGH
CS
*Note 2
tRC
RAS
CAS
*Note 1
*Note 3
ADDR
DQ
Key
Ra
Hi-Z
Hi-Z
WE
DQM
MRS
New
Auto Refresh
New Command
Command
: Don't care
* Both banks precharge should be completed before Mode Register Set cycle and auto refresh cycle.
MODE REGISTER SET CYCLE
*Note : 1. CS, RAS, CAS, & WE activation at the same clock cycle with address key will set internal mode register.
2. Minimum 2 clock cycles should be met before new RAS activation.
3. Please refer to Mode Register Set table.
Ver 0.0 Sep. '01
S8S3122X16
CMOS SDRAM
PACKAGE DIMENSIONS
50-TSOP2-400CF
Unit : Millimeters
0~8°
0.25 TYP
#50
#26
#25
#1
+0.075
-0.035
0.125
20.95
± 0.10
1.20MAX
± 0.10
1.00
0.10MAX
0.075MAX
[
]
0.80TYP
[0.80±0.08]
0.05MIN
(0.875)
0.30 +0.10
0.35 +0.10
-0.05
-0.05
Ver 0.0 Sep. '01
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