COP8SBE9HVA9/NOPB [TI]
IC,MICROCONTROLLER,8-BIT,COP800 CPU,CMOS,LDCC,44PIN,PLASTIC;
| 型号： | COP8SBE9HVA9/NOPB |
| 厂家： | 
TEXAS INSTRUMENTS |
| 描述： | IC,MICROCONTROLLER,8-BIT,COP800 CPU,CMOS,LDCC,44PIN,PLASTIC 微控制器 |
| 文件： | 总74页 (文件大小：896K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
PRELIMINARY
March 2004
COP8SBE9/SCE9
8-Bit CMOS Flash Microcontroller with 8k Memory,
Virtual EEPROM and Brownout Reset
single-chip CMOS device is suited for applications requiring
1.0 General Description
a full featured, in-system reprogrammable controller with
The COP8SBE9/SCE9 Flash microcontrollers are highly in-
large memory and low EMI. The same device is used for
™
tegrated COP8
Feature core devices, with 8k Flash
development, pre-production and volume production with a
range of COP8 software and hardware development tools.
memory and advanced features including Virtual EEPROM,
High Speed Timers, USART, and Brownout Reset. This
Devices included in this datasheet:
Max Input
I/O
Flash Program
Memory (bytes) (bytes)
RAM
Brownout
Voltage
Device
Clock
Packages
Temperature
Pins
Frequency
44 LLP, 44PLCC,
48 TSSOP
COP8SBE9
COP8SCE9
8k
8k
256
256
2.7V to 2.9V
4.17V to 4.5V
3.33 MHz
10 MHz
37,39
0˚C to +70˚C
0˚C to +70˚C
−40˚C to
44 LLP, 44PLCC,
48 TSSOP
37,39
+125˚C
n MICROWIRE/PLUS (Serial Peripheral Interface
Compatible)
n Clock Doubler
— 20 MHz operation from 10 MHz Oscillator
(COP8SCE9) with 0.5 µs Instruction Cycle
— 6.67 MHz operation from 3.33 MHz Oscillator
(COP8SBE9) with 1.5 µs Instruction Cycle
n Eleven multi-source vectored interrupts servicing:
— External Interrupt
— USART (2)
— Idle Timer T0
— Two Timers (each with 2 interrupts)
— MICROWIRE/PLUS Serial peripheral interface
— Multi-Input Wake-up
2.0 Features
KEY FEATURES
n 8k bytes Flash Program Memory with Security Feature
n Virtual EEPROM using Flash Program Memory
n 256byte volatile RAM
n USART with onchip baud generator
n 2.7V – 5.5V In-System Programmability of Flash
n High endurance -100k Read/Write Cycles
n Superior Data Retention - 100 years
n Dual Clock Operation with HALT/IDLE Power Save
Modes
n Two 16-bit timers:
— Timer T2 can operate at high speed (50 ns
resolution)
— Processor Independent PWM mode
— External Event counter mode
— Input Capture mode
— Software Trap
n Idle Timer with programmable interrupt interval
n 8-bit Stack Pointer SP (stack in RAM)
n Two 8-bit Register Indirect Data Memory Pointers
n True bit manipulation
n Brown-out Reset
n WATCHDOG and Clock Monitor logic
n Software selectable I/O options
— TRI-STATE Output/High Impedance Input
— Push-Pull Output
n High Current I/Os
— B0 – B3: 10 mA 0.3V
— All others: 10 mA 1.0V
@
@
OTHER FEATURES
n Single supply operation:
— 2.7V–5.5V (0˚C to +70˚C)
— 4.5V–5.5V (−40˚C to +125˚C)
n Quiet Design (low radiated emissions)
n Multi-Input Wake-up with optional interrupts
— Weak Pull Up Input
n Schmitt trigger inputs on I/O ports
n Temperature range: 0˚C to +70˚C and –40˚C to +125˚C
(COP8SCE9)
n Packaging: 44 PLCC, 44 LLP and 48 TSSOP
™
COP8 is a trademark of National Semiconductor Corporation.
© 2004 National Semiconductor Corporation
DS200327
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3.0 Block Diagram
20032763
4.0 Ordering Information
Part Numbering Scheme
9
COP8
SB
E
H
VA
8
Program
Memory
Size
Program
Memory
Type
Family and Feature Set
Indicator
Package
Type
No. Of Pins
Temperature
SB = Low Brownout Voltage
SC = High Brownout Voltage
E = 8k
9 = Flash
H = 44 Pin
I = 48 Pin
LQ = LLP
7 = -40 to +125˚C
9 = 0 to +70˚C
MT = TSSOP
VA = PLCC
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2
Table of Contents
1.0 General Description ..................................................................................................................................... 1
2.0 Features ....................................................................................................................................................... 1
3.0 Block Diagram .............................................................................................................................................. 2
4.0 Ordering Information .................................................................................................................................... 2
5.0 Connection Diagrams ................................................................................................................................... 6
6.0 Architectural Overview ................................................................................................................................. 8
6.1 EMI REDUCTION ...................................................................................................................................... 8
6.2 IN-SYSTEM PROGRAMMING AND VIRTUAL EEPROM ........................................................................ 8
6.3 DUAL CLOCK AND CLOCK DOUBLER ................................................................................................... 8
6.4 TRUE IN-SYSTEM EMULATION .............................................................................................................. 8
6.5 ARCHITECTURE ..................................................................................................................................... 8
6.6 INSTRUCTION SET ................................................................................................................................. 8
6.6.1 Key Instruction Set Features ............................................................................................................... 8
6.6.2 Single Byte/Single Cycle Code Execution ......................................................................................... 8
6.6.3 Many Single-Byte, Multi-Function Instructions .................................................................................... 8
6.6.4 Bit-Level Control .................................................................................................................................. 9
6.6.5 Register Set ......................................................................................................................................... 9
6.7 PACKAGING/PIN EFFICIENCY ................................................................................................................ 9
7.0 Absolute Maximum Ratings ....................................................................................................................... 10
8.0 Electrical Characteristics ............................................................................................................................ 10
9.0 Pin Descriptions ......................................................................................................................................... 15
9.1 EMULATION CONNECTION ................................................................................................................... 16
10.0 Functional Description .............................................................................................................................. 18
10.1 CPU REGISTERS ................................................................................................................................. 18
10.2 PROGRAM MEMORY ........................................................................................................................... 18
10.3 DATA MEMORY .................................................................................................................................... 18
10.4 DATA MEMORY SEGMENT RAM EXTENSION .................................................................................. 18
10.4.1 Virtual EEPROM .............................................................................................................................. 19
10.5 OPTION REGISTER ............................................................................................................................. 19
10.6 SECURITY ............................................................................................................................................ 20
10.7 RESET ................................................................................................................................................... 20
10.7.1 External Reset ................................................................................................................................. 21
10.7.2 On-Chip Brownout Reset ................................................................................................................. 21
10.8 OSCILLATOR CIRCUITS ...................................................................................................................... 23
10.8.1 Oscillator .......................................................................................................................................... 23
10.8.2 Clock Doubler .................................................................................................................................. 24
10.9 CONTROL REGISTERS ....................................................................................................................... 24
10.9.1 CNTRL Register (Address X'00EE) ................................................................................................. 24
10.9.2 PSW Register (Address X'00EF) ..................................................................................................... 24
10.9.3 ICNTRL Register (Address X'00E8) ................................................................................................ 24
10.9.4 T2CNTRL Register (Address X'00C6) ............................................................................................. 24
10.9.5 HSTCR Register (Address X'00AF) ................................................................................................ 24
10.9.6 ITMR Register (Address X'00CF) .................................................................................................... 25
11.0 In-System Programming ........................................................................................................................... 25
11.1 INTRODUCTION ................................................................................................................................... 25
11.2 FUNCTIONAL DESCRIPTION .............................................................................................................. 25
11.3 REGISTERS .......................................................................................................................................... 25
11.3.1 ISP Address Registers ..................................................................................................................... 25
11.3.2 ISP Read Data Register .................................................................................................................. 25
11.3.3 ISP Write Data Register ................................................................................................................... 26
11.3.4 ISP Write Timing Register ................................................................................................................ 26
11.4 MANEUVERING BACK AND FORTH BETWEEN FLASH MEMORY AND BOOT ROM ..................... 27
11.5 FORCED EXECUTION FROM BOOT ROM ......................................................................................... 27
11.6 RETURN TO FLASH MEMORY WITHOUT HARDWARE RESET ....................................................... 28
11.7 MICROWIRE/PLUS ISP ........................................................................................................................ 28
11.8 USER ISP AND VIRTUAL E2 ................................................................................................................ 28
11.9 RESTRICTIONS ON SOFTWARE WHEN CALLING ISP ROUTINES IN BOOT ROM ....................... 31
11.10 FLASH MEMORY DURABILITY CONSIDERATIONS ........................................................................ 31
12.0 Timers ....................................................................................................................................................... 32
12.1 TIMER T0 (IDLE TIMER) ...................................................................................................................... 32
12.1.1 ITMR Register .................................................................................................................................. 32
12.2 TIMER T1 AND TIMER T2 .................................................................................................................... 33
3
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Table of Contents (Continued)
12.2.1 Timer Operating Speeds .................................................................................................................. 33
12.2.2 Mode 1. Processor Independent PWM Mode ................................................................................. 33
12.2.3 Mode 2. External Event Counter Mode ........................................................................................... 34
12.2.4 Mode 3. Input Capture Mode .......................................................................................................... 34
12.3 TIMER CONTROL FLAGS .................................................................................................................... 35
13.0 Power Saving Features ............................................................................................................................ 36
13.1 POWER SAVE MODE CONTROL REGISTER .................................................................................... 36
13.2 OSCILLATOR STABILIZATION ............................................................................................................. 37
13.3 HIGH SPEED MODE OPERATION ...................................................................................................... 37
13.3.1 High Speed Halt Mode .................................................................................................................... 37
13.3.1.1 Entering The High Speed Halt Mode ......................................................................................... 37
13.3.1.2 Exiting The High Speed Halt Mode ........................................................................................... 37
13.3.1.3 HALT Exit Using Reset .............................................................................................................. 37
13.3.1.4 HALT Exit Using Multi-Input Wake-up ....................................................................................... 37
13.3.1.5 Options ....................................................................................................................................... 38
13.3.2 High Speed Idle Mode ..................................................................................................................... 38
13.4 DUAL CLOCK MODE OPERATION ...................................................................................................... 39
13.4.1 Dual Clock HALT Mode ................................................................................................................... 39
13.4.1.1 Entering The Dual Clock Halt Mode .......................................................................................... 39
13.4.1.2 Exiting The Dual Clock Halt Mode ............................................................................................. 39
13.4.1.3 HALT Exit Using Reset .............................................................................................................. 39
13.4.1.4 HALT Exit Using Multi-Input Wake-up ....................................................................................... 39
13.4.1.5 Options ....................................................................................................................................... 39
13.4.2 Dual Clock Idle Mode ...................................................................................................................... 39
13.5 LOW SPEED MODE OPERATION ....................................................................................................... 40
13.5.1 Low Speed HALT Mode ................................................................................................................... 40
13.5.1.1 Entering The Low Speed Halt Mode ......................................................................................... 40
13.5.1.2 Exiting The Low Speed Halt Mode ............................................................................................ 40
13.5.1.3 HALT Exit Using Reset .............................................................................................................. 40
13.5.1.4 HALT Exit Using Multi-Input Wake-up ....................................................................................... 40
13.5.1.5 Options ....................................................................................................................................... 40
13.5.2 Low Speed Idle Mode ...................................................................................................................... 40
13.6 MULTI-INPUT WAKE-UP ...................................................................................................................... 42
14.0 USART ..................................................................................................................................................... 42
14.1 USART CONTROL AND STATUS REGISTERS ................................................................................... 43
14.2 DESCRIPTION OF USART REGISTER BITS ...................................................................................... 43
14.3 ASSOCIATED I/O PINS ........................................................................................................................ 44
14.4 USART OPERATION ............................................................................................................................ 45
14.4.1 Asynchronous Mode ........................................................................................................................ 45
14.4.2 Synchronous Mode .......................................................................................................................... 45
14.5 FRAMING FORMATS ............................................................................................................................ 45
14.6 USART INTERRUPTS .......................................................................................................................... 46
14.7 BAUD CLOCK GENERATION .............................................................................................................. 46
14.8 EFFECT OF HALT/IDLE ....................................................................................................................... 48
14.9 DIAGNOSTIC ........................................................................................................................................ 48
14.10 ATTENTION MODE ............................................................................................................................. 48
14.11 BREAK GENERATION ........................................................................................................................ 48
15.0 Interrupts .................................................................................................................................................. 49
15.1 INTRODUCTION ................................................................................................................................... 49
15.2 MASKABLE INTERRUPTS ................................................................................................................... 49
15.3 VIS INSTRUCTION ............................................................................................................................... 50
15.3.1 VIS Execution .................................................................................................................................. 51
15.4 NON-MASKABLE INTERRUPT ............................................................................................................ 52
15.4.1 Pending Flag .................................................................................................................................... 52
15.4.2 Software Trap .................................................................................................................................. 52
15.4.2.1 Programming Example: External Interrupt ................................................................................. 53
15.5 PORT L INTERRUPTS .......................................................................................................................... 54
15.6 INTERRUPT SUMMARY ....................................................................................................................... 54
16.0 WATCHDOG/Clock Monitor ..................................................................................................................... 54
16.1 CLOCK MONITOR ................................................................................................................................ 55
16.2 WATCHDOG/CLOCK MONITOR OPERATION .................................................................................... 55
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4
Table of Contents (Continued)
16.3 WATCHDOG AND CLOCK MONITOR SUMMARY .............................................................................. 56
16.4 DETECTION OF ILLEGAL CONDITIONS ............................................................................................ 56
17.0 MICROWIRE/PLUS .................................................................................................................................. 56
17.1 MICROWIRE/PLUS OPERATION ......................................................................................................... 57
17.1.1 MICROWIRE/PLUS Master Mode Operation .................................................................................. 57
17.1.2 MICROWIRE/PLUS Slave Mode Operation .................................................................................... 57
17.1.2.1 Alternate SK Phase Operation and SK Idle Polarity ................................................................. 58
18.0 Memory Map ............................................................................................................................................ 59
19.0 Instruction Set .......................................................................................................................................... 60
19.1 INTRODUCTION ................................................................................................................................... 60
19.2 INSTRUCTION FEATURES .................................................................................................................. 60
19.3 ADDRESSING MODES ......................................................................................................................... 60
19.3.1 Operand Addressing Modes ............................................................................................................ 60
19.3.2 Tranfer-of-Control Addressing Modes .............................................................................................. 61
19.4 INSTRUCTION TYPES ......................................................................................................................... 62
19.4.1 Arithmetic Instructions ...................................................................................................................... 62
19.4.2 Transfer-of-Control Instructions ....................................................................................................... 62
19.4.3 Load and Exchange Instructions ..................................................................................................... 62
19.4.4 Logical Instructions .......................................................................................................................... 63
19.4.5 Accumulator Bit Manipulation Instructions ....................................................................................... 63
19.4.6 Stack Control Instructions ................................................................................................................ 63
19.4.7 Memory Bit Manipulation Instructions ............................................................................................. 63
19.4.8 Conditional Instructions ................................................................................................................... 63
19.4.9 No-Operation Instruction .................................................................................................................. 63
19.5 REGISTER AND SYMBOL DEFINITION .............................................................................................. 63
19.6 INSTRUCTION SET SUMMARY .......................................................................................................... 64
19.7 INSTRUCTION EXECUTION TIME ...................................................................................................... 65
20.0 Development Support .............................................................................................................................. 68
20.1 TOOLS ORDERING NUMBERS FOR THE COP8 FLASH FAMILY DEVICES ................................... 68
20.2 COP8 TOOLS OVERVIEW ................................................................................................................... 70
20.3 WHERE TO GET TOOLS ..................................................................................................................... 71
21.0 Revision History ....................................................................................................................................... 72
22.0 Physical Dimensions ................................................................................................................................ 73
5
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5.0 Connection Diagrams
20032764
Top View
Plastic Chip Package
See NS Package Number V44A
20032759
Top View
TSSOP Package
See NS Package Number MTD48
20032755
Top View
LLP Package
See NS Package Number LQA44A
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6
Pinouts for 44- and 48-Pin Packages
In System
48-Pin
TSSOP
Port
Type
Alt. Function
Emulation
Mode
44-Pin LLP
44-Pin PLCC
L0
L1
L2
L3
L4
L5
L6
L7
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I
MIWU or Low Speed OSC In
16
17
18
19
20
21
22
23
7
11
12
13
14
15
16
17
18
2
11
12
13
14
15
16
17
18
2
MIWU or CKX or Low Speed OSC Out
MIWU or TDX
MIWU or RDX
MIWU or T2A
MIWU or T2B
MIWU
MIWU
G0
G1
G2
G3
G4
G5
G6
G7
H0
INT
WDOUTa
Input
POUT
Output
Clock
8
3
3
T1B
9
4
4
T1A
10
11
12
13
14
42
43
44
1
5
5
SO
6
6
SK
7
7
SI
8
8
I
CKO
9
9
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
37
38
39
40
41
42
43
44
41
42
43
44
45
46
47
48
33
34
35
36
37
38
39
40
19
20
21
22
23
24
25
26
32
27
10
1
H1
H2
H3
H4
2
H5
3
H6
4
H7
5
A0
A1
A2
36
37
38
39
40
41
24
25
26
27
28
29
30
31
35
32
15
6
31
32
33
34
35
36
19
20
21
22
23
24
25
26
30
27
10
1
A3
A4
A5
A6
A7
B0
B1
B2
B3
B4
B5
B6
B7
DVCC
DGND
CKI
RESET
VCC
GND
I
I
RESET
a. G1 operation as WDOUT is controlled by Option Register bit 2.
7
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be bypassed by jumpers on the final application board, can
provide for software and hardware debugging using actual
production units.
6.0 Architectural Overview
6.1 EMI REDUCTION
The COP8SBE9/SCE9 devices incorporate circuitry that
guards against electromagnetic interference - an increasing
problem in today’s microcontroller board designs. National’s
patented EMI reduction technology offers low EMI clock
circuitry, gradual turn-on output drivers (GTOs) and internal
Icc smoothing filters, to help circumvent many of the EMI
issues influencing embedded control designs. National has
achieved 15 dB–20 dB reduction in EMI transmissions when
designs have incorporated its patented EMI reducing cir-
cuitry.
6.5 ARCHITECTURE
The COP8 family is based on a modified Harvard architec-
ture, which allows data tables to be accessed directly from
program memory. This is very important with modern
microcontroller-based applications, since program memory
is usually ROM or EPROM, while data memory is usually
RAM. Consequently constant data tables need to be con-
tained in non-volatile memory, so they are not lost when the
microcontroller is powered down. In a modified Harvard ar-
chitecture, instruction fetch and memory data transfers can
be overlapped with a two stage pipeline, which allows the
next instruction to be fetched from program memory while
the current instruction is being executed using data memory.
This is not possible with a Von Neumann single-address bus
architecture.
6.2 IN-SYSTEM PROGRAMMING AND VIRTUAL
EEPROM
The device includes a program in a boot ROM that provides
the capability, through the MICROWIRE/PLUS serial inter-
face, to erase, program and read the contents of the Flash
memory.
The COP8 family supports a software stack scheme that
allows the user to incorporate many subroutine calls. This
capability is important when using High Level Languages.
With a hardware stack, the user is limited to a small fixed
number of stack levels.
Additional routines are included in the boot ROM, which can
be called by the user program, to enable the user to custom-
ize in system software update capability if MICROWIRE/
PLUS is not desired.
Additional functions will copy blocks of data between the
RAM and the Flash Memory. These functions provide a
virtual EEPROM capability by allowing the user to emulate a
variable amount of EEPROM by initializing nonvolatile vari-
ables from the Flash Memory and occasionally restoring
these variables to the Flash Memory.
6.6 INSTRUCTION SET
In today’s 8-bit microcontroller application arena cost/
performance, flexibility and time to market are several of the
key issues that system designers face in attempting to build
well-engineered products that compete in the marketplace.
Many of these issues can be addressed through the manner
in which a microcontroller’s instruction set handles process-
ing tasks. And that’s why the COP8 family offers a unique
and code-efficient instruction set - one that provides the
flexibility, functionality, reduced costs and faster time to mar-
ket that today’s microcontroller based products require.
The contents of the boot ROM have been defined by Na-
tional. Execution of code from the boot ROM is dependent
on the state of the FLEX bit in the Option Register on exit
from RESET. If the FLEX bit is a zero, the Flash Memory is
assumed to be empty and execution from the boot ROM
begins. For further information on the FLEX bit, refer to
Section 4.5, Option Register.
Code efficiency is important because it enables designers to
pack more on-chip functionality into less program memory
space (ROM, OTP or Flash). Selecting a microcontroller with
less program memory size translates into lower system
costs, and the added security of knowing that more code can
be packed into the available program memory space.
6.3 DUAL CLOCK AND CLOCK DOUBLER
The device includes a versatile clocking system and two
oscillator circuits designed to drive a crystal or ceramic
resonator. The primary oscillator operates at high speed up
to 10 MHz. The secondary oscillator is optimized for opera-
tion at 32.768 kHz.
6.6.1 Key Instruction Set Features
The COP8 family incorporates a unique combination of in-
struction set features, which provide designers with optimum
code efficiency and program memory utilization.
The user can, through specified transition sequences
(please refer to Section 13.0 Power Saving Features), switch
execution between the high speed and low speed oscillators.
The unused oscillator can then be turned off to minimize
power dissipation. If the low speed oscillator is not used, the
pins are available as general purpose bidirectional ports.
6.6.2 Single Byte/Single Cycle Code Execution
The efficiency is due to the fact that the majority of instruc-
tions are of the single byte variety, resulting in minimum
program space. Because compact code does not occupy a
substantial amount of program memory space, designers
can integrate additional features and functionality into the
microcontroller program memory space. Also, the majority
instructions executed by the device are single cycle, result-
ing in minimum program execution time. In fact, 77% of the
instructions are single byte single cycle, providing greater
code and I/O efficiency, and faster code execution.
The operation of the CPU will use a clock at twice the
frequency of the selected oscillator (up to 20 MHz for high
speed operation and 65.536 kHz for low speed operation).
This doubled clock will be referred to in this document as
‘MCLK’. The frequency of the selected oscillator will be
referred to as CKI. Instruction execution occurs at one tenth
the selected MCLK rate.
6.4 TRUE IN-SYSTEM EMULATION
6.6.3 Many Single-Byte, Multi-Function Instructions
On-chip emulation capability has been added which allows
the user to perform true in-system emulation using final
production boards and devices. This simplifies testing and
evaluation of software in real environmental conditions. The
user, merely by providing for a standard connector which can
The COP8 instruction set utilizes many single-byte, multi-
function instructions. This enables a single instruction to
accomplish multiple functions, such as DRSZ, DCOR, JID,
LD (Load) and
X (Exchange) instructions with post-
incrementing and post-decrementing, to name just a few
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8
board space. All members of the COP8 family provide the
ability to set, reset and test any individual bit in the data
memory address space, including memory-mapped I/O ports
and associated registers.
6.0 Architectural Overview (Continued)
examples. In many cases, the instruction set can simulta-
neously execute as many as three functions with the same
single-byte instruction.
6.6.5 Register Set
JID: (Jump Indirect); Single byte instruction decodes exter-
nal events and jumps to corresponding service routines
(analogous to “DO CASE” statements in higher level lan-
guages).
Three memory-mapped pointers handle register indirect ad-
dressing and software stack pointer functions. The memory
data pointers allow the option of post-incrementing or post-
decrementing with the data movement instructions (LOAD/
EXCHANGE). And 15 memory-mapped registers allow de-
signers to optimize the precise implementation of certain
specific instructions.
LAID: (Load Accumulator-Indirect); Single byte look up table
instruction provides efficient data path from the program
memory to the CPU. This instruction can be used for table
lookup and to read the entire program memory for checksum
calculations.
6.7 PACKAGING/PIN EFFICIENCY
RETSK: (Return Skip); Single byte instruction allows return
from subroutine and skips next instruction. Decision to
branch can be made in the subroutine itself, saving code.
Real estate and board configuration considerations demand
maximum space and pin efficiency, particularly given today’s
high integration and small product form factors. Microcon-
troller users try to avoid using large packages to get the I/O
needed. Large packages take valuable board space and
increase device cost, two trade-offs that microcontroller de-
signs can ill afford.
AUTOINC/DEC: (Auto-Increment/Auto-Decrement); These
instructions use the two memory pointers B and X to effi-
ciently process a block of data (simplifying “FOR NEXT” or
other loop structures in higher level languages).
The COP8 family offers a wide range of packages and does
not waste pins.
6.6.4 Bit-Level Control
Bit-level control over many of the microcontroller’s I/O ports
provides a flexible means to ease layout concerns and save
9
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7.0 Absolute Maximum Ratings (Note
Total Current out of GND Pin (Sink)
Storage Temperature Range
ESD Protection Level
100 mA
−65˚C to +140˚C
2 kV (Human Body
Model)
1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Note 1: Absolute maximum ratings indicate limits beyond which damage to
the device may occur. DC and AC electrical specifications are not ensured
when operating the device at absolute maximum ratings.
Supply Voltage (VCC
Voltage at Any Pin
)
7V
−0.3V to VCC +0.3V
100 mA
Total Current into VCC Pin (Source)
8.0 Electrical Characteristics
DC Electrical Characteristics (0˚C ≤ TA ≤ +70˚C)
Datasheet min/max specification limits are guaranteed by design, test, or statistical analysis.
Parameter
Conditions
Min
2.7
10
Typ
Max
5.5
50 x 106
Units
V
Operating Voltage
Power Supply Rise Time
Power Supply Ripple (Note 2)
Supply Current (Note 3)
High Speed Mode
ns
Peak-to-Peak
0.1 VCC
V
CKI = 10 MHz
VCC = 5.5V, tC = 0.5 µs
VCC = 4.5V, tC = 1.5 µs
13.2
6
mA
mA
CKI = 3.33 MHz
Dual Clock Mode
CKI = 10 MHz, Low Speed OSC = 32 kHz
CKI = 3.33 MHz, Low Speed OSC = 32 kHz
Low Speed Mode
VCC = 5.5V, tC = 0.5 µs
VCC = 4.5V, tC = 1.5 µs
13.2
6
mA
mA
Low Speed OSC = 32 kHz
HALT Current with BOR Disabled (Note 4)
High Speed Mode
VCC = 5.5V
60
103
µA
<
<
VCC = 5.5V, CKI = 0 MHz
VCC = 5.5V, CKI = 0 MHz,
Low Speed OSC = 32 kHz
VCC = 5.5V, CKI = 0 MHz,
Low Speed OSC = 32 kHz
2
5
10
17
µA
µA
Dual Clock Mode
Low Speed Mode
<
5
17
µA
Idle Current (Note 3)
High Speed Mode
CKI = 10 MHz
VCC = 5.5V, tC = 0.5 µs
VCC = 4.5V, tC = 1.5 µs
2.5
1.2
mA
mA
CKI = 3.33 MHz
Dual Clock Mode
CKI = 10 MHz, Low Speed OSC = 32 kHz
CKI = 3.33 MHz, Low Speed OSC = 32 kHz
Low Speed Mode
VCC = 5.5V, tC = 0.5 µs
VCC = 4.5V, tC = 1.5 µs
2.5
1.2
mA
mA
Low Speed OSC = 32 kHz
Supply Current When Programming In ISP
Supply Current for BOR Feature
High Brownout Trip Level (COP8SCE9)
Low Brownout Trip Level (COP8SBE9)
Input Levels (VIH, VIL)
VCC = 5.5V
15
26
30
µA
mA
µA
V
VCC = 5.0V, tC = 0.5 µs
VCC = 5.5V
45
4.5
2.9
4.17
2.7
4.28
2.78
V
Logic High
0.8 VCC
V
V
Logic Low
0.16 VCC
2.5
Internal Bias Resistor for the CKI
Crystal/Resonator Oscillator
Hi-Z Input Leakage
0.3
1.0
MΩ
VCC = 5.5V
−0.5
−50
+0.5
µA
µA
V
Input Pullup Current
VCC = 5.5V, VIN = 0V
−210
Port Input Hysteresis
0.25 VCC
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10
8.0 Electrical Characteristics (Continued)
DC Electrical Characteristics (0˚C ≤ TA ≤ +70˚C) (Continued)
Datasheet min/max specification limits are guaranteed by design, test, or statistical analysis.
Parameter
Output Current Levels
Conditions
Min
Typ
Max
Units
B0-B3 Outputs
Source (Weak Pull-Up Mode)
VCC = 4.5V, VOH = 3.8V
VCC = 2.7V, VOH = 1.8V
VCC = 4.5V, VOH = 4.2V
VCC = 2.7V, VOH = 2.4V
VCC = 4.5V, VOL = 0.3V
VCC = 2.7V, VOL = 0.3V
−10
-5
µA
µA
Source (Push-Pull Mode) (Note 7)
Sink (Push-Pull Mode) (Note 7)
−10
−6
10
6
mA
mA
mA
mA
mA
Allowable Sink and Source Current per Pin
All Others
20
Source (Weak Pull-Up Mode)
VCC = 4.5V, VOH = 3.8V
VCC = 2.7V, VOH = 1.8V
VCC = 4.5V, VOH = 3.8V
VCC = 2.7V, VOH = 1.8V
VCC = 4.5V, VOL = 1.0V
VCC = 2.7V, VOL = 0.4V
−10
−5
µA
µA
mA
mA
mA
mA
mA
µA
mA
V
Source (Push-Pull Mode)
−7
−4
Sink (Push-Pull Mode) (Note 7)
10
3.5
Allowable Sink and Source Current per Pin
TRI-STATE Leakage
15
VCC = 5.5V
−0.5
2.0
+0.5
200
Maximum Input Current without Latchup (Note 5)
RAM Retention Voltage, VR (in HALT Mode)
Input Capacitance
7
pF
Voltage on G6 to Force Execution from Boot
ROM(Note 8)
G6 rise time must be slower
than 100 ns
2 x VCC
100
VCC + 7
V
G6 Rise Time to Force Execution from Boot ROM
nS
µA
>
Input Current on G6 when Input VCC
VIN = 11V, VCC = 5.5V
25˚C
500
100
Flash Memory Data Retention
yrs
Flash Memory Number of Erase/Write Cycles
See Table 13, Typical Flash
Memory Endurance
cycles
105
AC Electrical Characteristics (0˚C ≤ TA ≤ +70˚C)
Datasheet min/max specification limits are guaranteed by design, test, or statistical analysis.
Parameter
Instruction Cycle Time (tC)
Crystal/Resonator
Conditions
Min
Typ
Max
Units
(COP8SBE9)
2.7V ≤ VCC ≤ 5.5V
4.5V ≤ VCC ≤ 5.5V
1.5
(Note
10)
DC
DC
µs
µs
(COP8SCE9)
0.5
(Note
9)
Flash Memory Page Erase Time
See Table 13, Typical
Flash Memory
Endurance
1
8
ms
Flash Memory Mass Erase Time
Frequency of MICROWIRE/PLUS in
Slave Mode
ms
2
MHz
MICROWIRE/PLUS Setup Time (tUWS
)
20
20
ns
ns
MICROWIRE/PLUS Hold Time (tUWH
)
11
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AC Electrical Characteristics (0˚C ≤ TA ≤ +70˚C) (Continued)
Datasheet min/max specification limits are guaranteed by design, test, or statistical analysis.
Parameter
Conditions
Min
Typ
Max
Units
MICROWIRE/PLUS Output Propagation
150
ns
Delay (tUPD
)
Input Pulse Width
Interrupt Input High Time
Interrupt Input Low Time
Timer 1 Input High Time
Timer 1 Input Low Time
Timer 2 Input High Time (Note 6)
Timer 2 Input Low Time (Note 6)
Output Pulse Width
1
1
1
1
1
1
tC
tC
tC
tC
MCLK or tC
MCLK or tC
Timer 2 Output High Time
Timer 2 Output Low Time
USART Bit Time when using External
CKX
150
150
ns
ns
6 CKI
periods
USART CKX Frequency when being
Driven by Internal Baud Rate Generator
Reset Pulse Width
2
MHz
tC
1
t
= instruction cycle time.
C
<
Note 2: Maximum rate of voltage change must be 0.5 V/ms.
Note 3: Supply and IDLE currents are measured with CKI driven with a square wave Oscillator, CKO driven 180˚ out of phase with CKI, inputs connected to V
CC
and outputs driven low but not connected to a load.
Note 4: The HALT mode will stop CKI from oscillating. Measurement of I HALT is done with device neither sourcing nor sinking current; with A. B, G0, G2–G5,
DD
H and L programmed as low outputs and not driving a load; all inputs tied to V ; A/D converter and clock monitor and BOR disabled. Parameter refers to HALT
CC
mode entered via setting bit 7 of the G Port data register.
>
Note 5: Pins G6 and RESET are designed with a high voltage input network. These pins allow input voltages
V
and the pins will have sink current to V when
CC CC
>
biased at voltages
V
(the pins do not have source current when biased at a voltage below V ). These two pins will not latch up. The voltage at the pins must
be limited to 14V. WARNING: Voltages in excess of 14V will cause damage to the pins. This warning excludes ESD transients.
C
C
C
C
<
Note 6: If timer is in high speed mode, the minimum time is 1 MCLK. If timer is not in high speed mode, the minimum time is 1 t
Note 7: Absolute Maximum Ratings should not be exceeded.
.
C
Note 8: V must be valid and stable before G6 is raised to a high voltage.
cc
Note 9: Corresponds to 10 MHz maximum input clock frequency.
Note 10: Corresponds to 3.33 MHz maximum input clock frequency.
www.national.com
12
DC Electrical Characteristics (−40˚C ≤ TA ≤ +125˚C)
Datasheet min/max specification limits are guaranteed by design, test, or statistical analysis.
Parameter
Conditions
Min
4.5
10
Typ
Max
5.5
50 x 106
Units
V
Operating Voltage
Power Supply Rise Time
Power Supply Ripple (Note 2)
Supply Current (Note 3)
High Speed Mode
ns
Peak-to-Peak
0.1 VCC
V
CKI = 10 MHz
VCC = 5.5V, tC = 0.5 µs
VCC = 4.5V, tC = 1.5 µs
14.5
7.0
mA
mA
CKI = 3.33 MHz
Dual Clock Mode
CKI = 10 MHz, Low Speed OSC = 32 kHz
CKI = 3.33 MHz, Low Speed OSC = 32 kHz
Low Speed Mode
VCC = 5.5V, tC = 0.5 µs
VCC = 4.5V, tC = 1.5 µs
14.5
7.0
mA
mA
Low Speed OSC = 32 kHz
HALT Current with BOR Disabled (Note 4)
High Speed Mode
VCC = 5.5V
65
110
µA
<
<
VCC = 5.5V, CKI = 0 MHz
VCC = 5.5V, CKI = 0 MHz,
Low Speed OSC = 32 kHz
VCC = 5.5V, CKI = 0 MHz,
Low Speed OSC = 32 kHz
4
9
40
50
µA
µA
Dual Clock Mode
Low Speed Mode
<
9
50
µA
Idle Current (Note 3)
High Speed Mode
CKI = 10 MHz
VCC = 5.5V, tC = 0.5 µs
VCC = 5.5V, tC = 0.5 µs
2.7
2.7
70
mA
mA
Dual Clock Mode
CKI = 10 MHz, Low Speed OSC = 32 kHz
Low Speed Mode
Low Speed OSC = 32 kHz
Supply Current When Programming In ISP
Supply Current for BOR Feature
High Brownout Trip Level
Input Levels (VIH, VIL)
VCC = 5.5V
30
26
µA
mA
µA
V
VCC = 5.0V, tC = 0.5 µs
VCC = 5.5V
45
4.17
4.28
4.5
Logic High
0.8 VCC
V
V
Logic Low
0.16 VCC
2.5
Internal Bias Resistor for the CKI Crystal/Resonator
Oscillator
0.3
1.0
MΩ
Hi-Z Input Leakage
VCC = 5.5V
−3
−40
+3
µA
µA
V
Input Pullup Current
VCC = 5.5V, VIN = 0V
−250
Port Input Hysteresis
0.25 VCC
Output Current Levels
B0-B3 Outputs
Source (Weak Pull-Up Mode)
Source (Push-Pull Mode)
Sink (Push-Pull Mode) (Note 7)
Allowable Sink and Source Current per Pin
All Others
VCC = 4.5V, VOH = 3.8V
VCC = 4.5V, VOH = 4.2V
VCC = 4.5V, VOL = 0.3V
−9
−9
9
µA
mA
mA
mA
15
Source (Weak Pull-Up Mode)
Source (Push-Pull Mode)
Sink (Push-Pull Mode) (Note 7)
Allowable Sink and Source Current per Pin
TRI-STATE Leakage
VCC = 4.5V, VOH = 3.8V
VCC = 4.5V, VOH = 3.8V
VCC = 4.5V, VOL = 1.0V
−9
−6.3
9
µA
mA
mA
mA
µA
12
VCC = 5.5V
−3
+3
Maximum Input Current without Latchup (Note 5)
200
mA
13
www.national.com
DC Electrical Characteristics (−40˚C ≤ TA ≤ +125˚C) (Continued)
Datasheet min/max specification limits are guaranteed by design, test, or statistical analysis.
Parameter
RAM Retention Voltage, VR (in HALT Mode)
Input Capacitance
Conditions
Min
Typ
Max
Units
V
2.0
7
pF
Voltage on G6 to Force Execution from Boot
ROM(Note 8)
G6 rise time must be slower
than 100 ns
2 x VCC
100
VCC + 7
V
G6 Rise Time to Force Execution from Boot ROM
nS
µA
>
Input Current on G6 when Input VCC
VIN = 11V, VCC = 5.5V
500
AC Electrical Characteristics (−40˚C ≤ TA ≤ +125˚C)
Datasheet min/max specification limits are guaranteed by design, test, or statistical analysis.
Parameter
Instruction Cycle Time (tC)
Crystal/Resonator
Conditions
Min
Typ
Max
Units
4.5V ≤ VCC ≤ 5.5V
0.5
DC
2
µs
Output Propagation Delay
Frequency of MICROWIRE/PLUS in Slave
Mode
RL =2.2k, CL = 100 pF
MHz
MICROWIRE/PLUS Setup Time (tUWS
MICROWIRE/PLUS Hold Time (tUWH
MICROWIRE/PLUS Output Propagation Delay
(tUPD
)
20
20
ns
ns
)
150
ns
)
Input Pulse Width
Interrupt Input High Time
1
1
1
1
1
1
tC
Interrupt Input Low Time
tC
tC
Timer 1 Input High Time
Timer 1 Input Low Time
tC
Timer 2, 3 Input High Time (Note 6)
Timer 2, 3 Input Low Time (Note 6)
Output Pulse Width
MCLK or tC
MCLK or tC
Timer 2, 3 Output High Time
Timer 2, 3 Output Low Time
USART Bit Time when using External CKX
150
150
ns
ns
6 CKI
periods
USART CKX Frequency when being Driven by
Internal Baud Rate Generator
Reset Pulse Width
2
MHz
tC
0.5
t
= instruction cycle time.
C
<
Note 11: Maximum rate of voltage change must be 0.5 V/ms.
Note 12: Supply and IDLE currents are measured with CKI driven with a square wave Oscillator, CKO driven 180˚ out of phase with CKI, inputs connected to V
CC
and outputs driven low but not connected to a load.
Note 13: The HALT mode will stop CKI from oscillating. Measurement of I
HALT is done with device neither sourcing nor sinking current; with L. A. B, C, E, F,
DD
G0, and G2–G5 programmed as low outputs and not driving a load; all D outputs programmed low and not driving a load; all inputs tied to V ; A/D converter and
CC
clock monitor and BOR disabled. Parameter refers to HALT mode entered via setting bit 7 of the G Port data register.
>
Note 14: Pins G6 and RESET are designed with a high voltage input network. These pins allow input voltages
V
and the pins will have sink current to V
CC CC
>
when biased at voltages
V
(the pins do not have source current when biased at a voltage below V ). These two pins will not latch up. The voltage at the pins
+ 7V. WARNING: Voltages in excess of 14V will cause damage to the pins. This warning excludes ESD transients.
C
C
C
C
<
must be limited to (V
CC
Note 15: If timer is in high speed mode, the minimum time is 1 MCLK. If timer is not in high speed mode, the minimum time is 1 t
Note 16: Absolute Maximum Ratings should not be exceeded.
.
C
Note 17: V must be valid and stable before G6 is raised to a high voltage.
cc
www.national.com
14
20032705
FIGURE 1. MICROWIRE/PLUS Timing
dently configured as an input (Schmitt trigger inputs on ports
L and G), output or TRI-STATE under program control. Three
data memory address locations are allocated for each of
these I/O ports. Each I/O port has three associated 8-bit
memory mapped registers, the CONFIGURATION register,
the output DATA register and the Pin input register. (See the
memory map for the various addresses associated with the
I/O ports.) Figure 3 shows the I/O port configurations. The
DATA and CONFIGURATION registers allow for each port bit
to be individually configured under software control as
shown below:
9.0 Pin Descriptions
The COP8SBE/SCE I/O structure enables designers to re-
configure the microcontroller’s I/O functions with a single
instruction. Each individual I/O pin can be independently
configured as output pin low, output high, input with high
impedance or input with weak pull-up device. A typical ex-
ample is the use of I/O pins as the keyboard matrix input
lines. The input lines can be programmed with internal weak
pull-ups so that the input lines read logic high when the keys
are all open. With a key closure, the corresponding input line
will read a logic zero since the weak pull-up can easily be
overdriven. When the key is released, the internal weak
pull-up will pull the input line back to logic high. This elimi-
nates the need for external pull-up resistors. The high cur-
rent options are available for driving LEDs, motors and
speakers. This flexibility helps to ensure a cleaner design,
with less external components and lower costs. Below is the
general description of all available pins.
CONFIGURATION
Register
DATA
Port Set-Up
Hi-Z Input
Register
0
0
(TRI-STATE Output)
Input with Weak Pull-Up
Push-Pull Zero Output
Push-Pull One Output
0
1
1
1
0
1
VCC and GND are the power supply pins. All VCC and GND
pins must be connected.
Port A is an 8-bit I/O port. All A pins have Schmitt triggers on
the inputs. The 44-pin packages do not have a full 8-bit port
and contain some unbonded, floating pads internally on the
chip. The binary value read from these bits is undetermined.
The application software should mask out these unknown
bits when reading the Port A register, or use only bit-access
program instructions when accessing Port A. These uncon-
nected bits draw power only when they are addressed (i.e.,
in brief spikes).
Users of the LLP package are cautioned to be aware that the
central metal area and the pin 1 index mark on the bottom of
the package may be connected to GND. See figure below:
Port B is an 8-bit I/O port. All B pins have Schmitt triggers on
the inputs.
Port G is an 8-bit port. Pin G0, G2–G5 are bi-directional I/O
ports. Pin G6 is always a general purpose Hi-Z input. All pins
have Schmitt Triggers on their inputs. Pin G1 serves as the
dedicated WATCHDOG output with weak pull-up if the
WATCHDOG feature is selected by the Option register.
The pin is a general purpose I/O if WATCHDOG feature is
not selected. If WATCHDOG feature is selected, bit 1 of the
Port G configuration and data register does not have any
effect on Pin G1 setup. G7 serves as the dedicated output
pin for the CKO clock output.
20032770
Since G6 is an input only pin and G7 is the dedicated CKO
clock output pin, the associated bits in the data and configu-
ration registers for G6 and G7 are used for special purpose
functions as outlined below. Reading the G6 and G7 data
bits will return zeros.
FIGURE 2.
CKI is the clock input. This can be connected (in conjunction
with CKO) to an external crystal circuit to form a crystal
oscillator. See Oscillator Description section.
The device will be placed in the HALT mode by writing a “1”
to bit 7 of the Port G Data Register. Similarly the device will
be placed in the IDLE mode by writing a “1” to bit 6 of the
Port G Data Register.
RESET is the master reset input. See Reset description
section.
The device contains up to six bidirectional 8-bit I/O ports (A,
B, G, H and L), where each individual bit may be indepen-
15
www.national.com
9.0 Pin Descriptions (Continued)
Writing a “1” to bit 6 of the Port G Configuration Register
enables the MICROWIRE/PLUS to operate with the alter-
nate phase of the SK clock. The G7 configuration bit, if set
high, enables the clock start up delay after HALT when the
R/C clock configuration is used.
Config. Reg.
CLKDLY
Alternate SK
Data Reg.
HALT
IDLE
G7
G6
Port G has the following alternate features:
G7 CKO Oscillator dedicated output
G6 SI (MICROWIRE/PLUS Serial Data Input)
G5 SK (MICROWIRE/PLUS Serial Clock)
G4 SO (MICROWIRE/PLUS Serial Data Output)
G3 T1A (Timer T1 I/O)
20032761
FIGURE 4. I/O Port Configurations—Output Mode
G2 T1B (Timer T1 Capture Input)
G1 WDOUT WATCHDOG and/or Clock Monitor if WATCH-
DOG enabled, otherwise it is a general purpose I/O
G0 INTR (External Interrupt Input)
G0 through G3 are also used for In-System Emulation.
Port H is an 8-bit I/O port. All H pins have Schmitt triggers on
the inputs.
Port L is an 8-bit I/O port. All L-pins have Schmitt triggers on
the inputs.
Port L supports the Multi-Input Wake-up feature on all eight
pins. Port L has the following alternate pin functions:
L7 Multi-Input Wake-up
L6 Multi-Input Wake-up
20032762
L5 Multi-Input Wake-up or T2B (Timer T2B Input)
L4 Multi-input Wake-up or T2A (Timer T2A Input/Output)
L3 Multi-Input Wake-up and/or RDX (USART Receive)
L2 Multi-Input Wake-up or TDX (USART Transmit)
FIGURE 5. I/O Port Configurations—Input Mode
9.1 EMULATION CONNECTION
L1 Multi-Input Wake-up and/or CKX (USART Clock) (Low
Speed Oscillator Output)
Connection to the emulation system is made via a 2 x 7
connector which interrupts the continuity of the RESET, G0,
G1, G2 and G3 signals between the COP8 device and the
rest of the target system (as shown in Figure 6). This con-
nector can be designed into the production pc board and can
be replaced by jumpers or signal traces when emulation is
no longer necessary. The emulator will replicate all functions
of G0 - G3 and RESET. For proper operation, no connection
should be made on the device side of the emulator connec-
tor.
L0 Multi-Input Wake-up (Low Speed Oscillator Input)
20032760
FIGURE 3. I/O Port Configurations
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16
9.0 Pin Descriptions (Continued)
20032709
FIGURE 6. Emulation Connection
17
www.national.com
RAM address 06F Hex. The SP is decremented as items are
pushed onto the stack. SP points to the next available loca-
tion on the stack.
10.0 Functional Description
The architecture of the device is a modified Harvard archi-
tecture. With the Harvard architecture, the program memory
(Flash) is separate from the data store memory (RAM). Both
Program Memory and Data Memory have their own separate
addressing space with separate address buses. The archi-
tecture, though based on the Harvard architecture, permits
transfer of data from Flash Memory to RAM.
All the CPU registers are memory mapped with the excep-
tion of the Accumulator (A) and the Program Counter (PC).
10.2 PROGRAM MEMORY
The program memory consists of 8192 bytes of Flash
Memory. These bytes may hold program instructions or con-
stant data (data tables for the LAID instruction, jump vectors
for the JID instruction, and interrupt vectors for the VIS
instruction). The program memory is addressed by the 15-bit
program counter (PC). All interrupts in the device vector to
program memory location 00FF Hex. The program memory
reads 00 Hex in the erased state. Program execution starts
at location 0 after RESET.
10.1 CPU REGISTERS
The CPU can do an 8-bit addition, subtraction, logical or shift
operation in one instruction (tC) cycle time.
There are six CPU registers:
A is the 8-bit Accumulator Register
PC is the 15-bit Program Counter Register
PU is the upper 7 bits of the program counter (PC)
PL is the lower 8 bits of the program counter (PC)
If a Return instruction is executed when the SP contains 6F
(hex), instruction execution will continue from Program
Memory location 7FFF (hex). If location 7FFF is accessed by
an instruction fetch, the Flash Memory will return a value of
00. This is the opcode for the INTR instruction and will cause
a Software Trap.
B is an 8-bit RAM address pointer, which can be optionally
post auto incremented or decremented.
X is an 8-bit alternate RAM address pointer, which can be
optionally post auto incremented or decremented.
For the purpose of erasing and rewriting the Flash Memory,
S is the 8-bit Data Segment Address Register used to extend
the lower half of the address range (00 to 7F) into 256 data
segments of 128 bytes each.
it is organized in pages of 64 bytes as show in Table 1.
SP is the 8-bit stack pointer, which points to the subroutine/
interrupt stack (in RAM). With reset the SP is initialized to
TABLE 1. Available Memory Address Ranges
Maximum
RAM
Address
(HEX)
Program
Memory
Size (Flash)
Flash Memory
Page Size
(Bytes)
Option Register Data Memory
Segments
Available
Device
Address (Hex)
Size (RAM)
COP8SBE9
COP8SCE9
8192
64
1FFF
256
0-1
017F
10.3 DATA MEMORY
The data store memory is either addressed directly by a
single byte address within the instruction, or indirectly rela-
tive to the reference of the B, X, or SP pointers (each
contains a single-byte address). This single-byte address
allows an addressing range of 256 locations from 00 to FF
hex. The upper bit of this single-byte address divides the
data store memory into two separate sections as outlined
previously. With the exception of the RAM register memory
from address locations 00F0 – 00FF, all RAM memory is
memory mapped with the upper bit of the single-byte ad-
dress being equal to zero. This allows the upper bit of the
single-byte address to determine whether or not the base
address range (from 0000 – 00FF) is extended. If this upper
bit equals one (representing address range 0080 – 00FF),
then address extension does not take place. Alternatively, if
this upper bit equals zero, then the data segment extension
register S is used to extend the base address range from
0000 – 007F to XX00 – XX7F, where XX represents the 8
bits from the S register. Thus the 128-byte data segment
extensions are located from addresses 0100 – 017F for data
segment 1, 0200 – 027F for data segment 2, etc., up to FF00
– FF7F for data segment 255. The base address range from
0000 – 007F represents data segment 0.
The data memory address space includes the on-chip RAM
and data registers, the I/O registers (Configuration, Data and
Pin), the control registers, the MICROWIRE/PLUS SIO shift
register, and the various registers, and counters associated
with the timers and the USART (with the exception of the
IDLE timer). Data memory is addressed directly by the in-
struction or indirectly by the B, X and SP pointers.
The data memory consists of 256 bytes of RAM. Sixteen
bytes of RAM are mapped as “registers” at addresses 0F0 to
0FF Hex. These registers can be loaded immediately, and
also decremented and tested with the DRSZ (decrement
register and skip if zero) instruction. The memory pointer
registers X, SP, B and S are memory mapped into this space
at address locations 0FC to 0FF Hex respectively, with the
other registers being available for general usage.
The instruction set permits any bit in memory to be set, reset
or tested. All I/O and registers (except A and PC) are
memory mapped; therefore, I/O bits and register bits can be
directly and individually set, reset and tested. The accumu-
lator (A) bits can also be directly and individually tested.
Note: RAM contents are undefined upon power-up.
Refer to Table 1, to determine available RAM segments for
this device.
10.4 DATA MEMORY SEGMENT RAM EXTENSION
Data memory address 0FF is used as a memory mapped
location for the Data Segment Address Register (S).
Figure 7 illustrates how the S register data memory exten-
sion is used in extending the lower half of the base address
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18
stack (used with subroutine linkage and interrupts) is always
located in the base segment. The stack pointer will be initial-
ized to point at data memory location 006F as a result of
reset.
10.0 Functional Description
(Continued)
range (00 to 7F hex) into 256 data segments of 128 bytes
each, with a total addressing range of 32 kbytes from XX00
to XX7F. This organization allows a total of 256 data seg-
ments of 128 bytes each with an additional upper base
segment of 128 bytes. Furthermore, all addressing modes
are available for all data segments. The S register must be
changed under program control to move from one data
segment (128 bytes) to another. However, the upper base
segment (containing the 16 memory registers, I/O registers,
control registers, etc.) is always available regardless of the
contents of the S register, since the upper base segment
(address range 0080 to 00FF) is independent of data seg-
ment extension.
The 128 bytes of RAM contained in the base segment are
split between the lower and upper base segments. The first
112 bytes of RAM are resident from address 0000 to 006F in
the lower base segment, while the remaining 16 bytes of
RAM represent the 16 data memory registers located at
addresses 00F0 to 00FF of the upper base segment. No
RAM is located at the upper sixteen addresses (0070 to
007F) of the lower base segment.
Additional RAM beyond these initial 128 bytes, however, will
always be memory mapped in groups of 128 bytes (or less)
at the data segment address extensions (XX00 to XX7F) of
the lower base segment. The additional 128 bytes of RAM in
this device are memory mapped at address locations 0100
through 017F.
The instructions that utilize the stack pointer (SP) always
reference the stack as part of the base segment (Segment
0), regardless of the contents of the S register. The S register
is not changed by these instructions. Consequently, the
20032710
FIGURE 7. RAM Organization
10.4.1 Virtual EEPROM
10.5 OPTION REGISTER
The Flash memory and the User ISP functions (see Section
5.7), provide the user with the capability to use the flash
program memory to back up user defined sections of RAM.
This effectively provides the user with the same nonvolatile
data storage as EEPROM. Management, and even the
amount of memory used, are the responsibility of the user,
however the flash memory read and write functions have
been provided in the boot ROM.
The Option register, located at address 0x3FFF (hex) in the
Flash Program Memory, is used to configure the user select-
able security, WATCHDOG, and HALT options. The register
can be programmed only in external Flash Memory program-
ming or ISP Programming modes. Therefore, the register
must be programmed at the same time as the program
memory. The contents of the Option register shipped from
the factory read 00 Hex.
One typical method of using the Virtual EEPROM feature
would be for the user to copy the data to RAM during system
initialization, periodically, and if necessary, erase the page of
Flash and copy the contents of the RAM back to the Flash.
The format of the Option register is as follows:
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
WATCH
DOG
Reserved
SECURITY
Reserved
HALT
FLEX
Bits 7, 6 These bits are reserved and must be 0.
19
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enforced by the user when the contents of the Flash
Memory are accessed via the user ISP or Virtual EE-
PROM capability.
10.0 Functional Description
(Continued)
Bit 5
If the security feature is enabled, then any attempt to exter-
nally read the contents of the Flash Memory will result in the
value FF (hex) being read from all program locations (except
the Option Register). In addition, with the security feature
enabled, the write operation to the Flash program memory
and Option Register is inhibited. Page Erases are also inhib-
ited when the security feature is enabled. The Option Reg-
ister is readable regardless of the state of the security bit by
accessing location FFFF (hex). Mass Erase Operations are
possible regardless of the state of the security bit.
= 1
= 0
Security enabled. Flash Memory read and write
are not allowed except in User ISP/Virtual E2 com-
mands. Mass Erase is allowed.
Security disabled. Flash Memory read and write
are allowed.
Bits 4, 3 These bits are reserved and must be 0.
Bit 2
= 1
WATCHDOG feature disabled. G1 is a general
purpose I/O.
The security bit can be erased only by a Mass Erase of the
entire contents of the Flash unless Flash operation is under
the control of User ISP functions.
= 0
WATCHDOG feature enabled. G1 pin is
WATCHDOG output with weak pullup.
Note: The actual memory address of the Option Register is
0x3FFF (hex), however the MICROWIRE/PLUS ISP routines
require the address FFFF (hex) to be used to read the
Option Register when the Flash Memory is secured.
Bit 1
= 1
= 0
HALT mode disabled.
HALT mode enabled.
Bit 0
The entire Option Register must be programmed at one time
and cannot be rewritten without first erasing the entire last
page of Flash Memory.
= 1
Execution following RESET will be from Flash
Memory.
= 0
Flash Memory is erased. Execution following RE-
SET will be from Boot ROM with the MICROWIRE/
PLUS ISP routines.
10.7 RESET
The device is initialized when the RESET pin is pulled low or
the On-chip Brownout Reset is activated.
The COP8 assembler defines a special ROM section type,
CONF, into which the Option Register data may be coded.
The Option Register is programmed automatically by pro-
grammers that are certified by National.
The user needs to ensure that the FLEX bit will be set when
the device is programmed.
The following examples illustrate the declaration of the Op-
tion Register.
20032711
Syntax:
[label:].sect
.db
config, conf
value ;1 byte,
FIGURE 8. Reset Logic
;configures
;options
The following occurs upon initialization:
Port A: TRI-STATE (High Impedance Input)
Port B: TRI-STATE (High Impedance Input)
.endsect
Example: The following sets a value in the Option Register
and User Identification for a COP8SBE9HVA7. The Option
Register bit values shown select options: Security disabled,
WATCHDOG enabled HALT mode enabled and execution
will commence from Flash Memory.
Port G: TRI-STATE (High Impedance Input). Exceptions: If
Watchdog is enabled, then G1 is Watchdog output. G0
and G2 have their weak pull-up enabled during RESET.
Port H: TRI-STATE (High Impedance Input)
Port L: TRI-STATE (High Impedance Input)
PC: CLEARED to 0000
.chip
.sect
.db
8SBE
option, conf
0x01
;wd, halt, flex
PSW, CNTRL and ICNTRL registers: CLEARED
SIOR:
.endsect
...
UNAFFECTED after RESET with power already applied
RANDOM after RESET at power-on
T2CNTRL: CLEARED
.end
start
Note: All programmers certified for programming this family
of parts will support programming of the Option Register.
Please contact National or your device programmer supplier
for more information.
HSTCR: CLEARED
ITMR: Cleared except Bit 6 (HSON) = 1
Accumulator, Timer 1 and Timer 2:
RANDOM after RESET
10.6 SECURITY
The device has a security feature which, when enabled,
prevents external reading of the Flash program memory. The
security bit in the Option Register determines, whether se-
curity is enabled or disabled. If the security feature is dis-
abled, the contents of the internal Flash Memory may be
read by external programmers or by the built in
MICROWIRE/PLUS serial interface ISP. Security must be
WKEN, WKEDG: CLEARED
WKPND: RANDOM
SP (Stack Pointer):
Initialized to RAM address 06F Hex
B and X Pointers:
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20
RESET may also be used to cause an exit from the HALT
mode.
10.0 Functional Description
(Continued)
A recommended reset circuit for this device is shown in
UNAFFECTED after RESET with power already applied
RANDOM after RESET at power-on
S Register: CLEARED
Figure 9.
RAM:
UNAFFECTED after RESET with power already applied
RANDOM after RESET at power-on
USART:
PSR, ENU, ENUR, ENUI: Cleared except the TBMT bit
which is set to one.
ISP CONTROL:
ISPADLO: CLEARED
20032712
ISPADHI: CLEARED
PGMTIM: PRESET TO VALUE FOR 10 MHz CKI
WATCHDOG (if enabled):
FIGURE 9. Reset Circuit Using External Reset
The device comes out of reset with both the WATCHDOG
logic and the Clock Monitor detector armed, with the
WATCHDOG service window bits set and the Clock Moni-
tor bit set. The WATCHDOG and Clock Monitor circuits
are inhibited during reset. The WATCHDOG service win-
dow bits being initialized high default to the maximum
WATCHDOG service window of 64k T0 clock cycles. The
Clock Monitor bit being initialized high will cause a Clock
Monitor error following reset if the clock has not reached
the minimum specified frequency at the termination of
reset. A Clock Monitor error will cause an active low error
output on pin G1. This error output will continue until
16–32 T0 clock cycles following the clock frequency
reaching the minimum specified value, at which time the
G1 output will go high.
10.7.2 On-Chip Brownout Reset
The device generates an internal reset as VCC rises. While
VCC is less than the specified brownout voltage (Vbor), the
device is held in the reset condition and the Idle Timer is
preset with 00Fx (240–256 tC). When VCC reaches a value
greater than Vbor, the Idle Timer starts counting down. Upon
underflow of the Idle Timer, the internal reset is released and
the device will start executing instructions. This internal reset
will perform the same functions as external reset. Once VCC
is above Vbor and this initial Idle Timer time-out takes place,
instruction execution begins and the Idle Timer can be used
normally. If, however, VCC drops below the selected Vbor, an
internal reset is generated, and the Idle Timer is preset with
00Fx. The device now waits until VCC is greater than Vbor
and the countdown starts over. When enabled, the functional
operation of the device, at frequency, is guaranteed down to
the Vbor level.
10.7.1 External Reset
The RESET input, when pulled low, initializes the device.
The RESET pin must be held low for a minimum of one
instruction cycle to guarantee a valid reset.
21
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10.0 Functional Description (Continued)
20032713
FIGURE 10. Brownout Reset Operation
One exception to the above is that the brownout circuit will
insert a delay of approximately 3 ms on power up or any time
VCC drops below a voltage of about 1.8V. The device will be
held in Reset for the duration of this delay before the Idle
Timer starts counting the 240 to 256 tC. This delay starts as
soon as the VCC rises above the trigger voltage (approxi-
mately 1.8V). This behavior is shown in Figure 10.
filtering of VCC be done to ensure that the brownout feature
works correctly. Power supply decoupling is vital even in
battery powered systems.
There are two optional brownout voltages. The part numbers
for the two versions of this device are:
COP8SBE, Vbor = low voltage range
COP8SCE, Vbor = high voltage range
In Case 1, VCC rises from 0V and the on-chip RESET is
undefined until the supply is greater than approximately
1.0V. At this time the brownout circuit becomes active and
holds the device in RESET. As the supply passes a level of
about 1.8V, a delay of about 3 ms (td) is started and the Idle
Timer is preset to a value between 00F0 and 00FF (hex).
Once VCC is greater than Vbor and td has expired, the Idle
Timer is allowed to count down (tid).
Refer to the device specifications for the actual Vbor volt-
ages.
High brownout voltage devices are guaranteed to operate at
10MHz down to the high brownout voltage. Low brownout
voltage devices are guaranteed to operate at 3.33MHz down
to the low brownout voltage. Low brownout voltage de-
vices are not guaranteed to operate at 10MHz down to
the low brownout voltage.
Case 2 shows a subsequent dip in the supply voltage which
goes below the approximate 1.8V level. As VCC drops below
Vbor, the internal RESET signal is asserted. When VCC rises
back above the 1.8V level, td is started. Since the power
supply rise time is longer for this case, td has expired before
VCC rises above Vbor and tid starts immediately when VCC is
Under no circumstances should the RESET pin be allowed
to float. If only the on-chip Brownout Reset feature is being
used, the RESET pin should be connected directly to VCC
.
The RESET input may also be connected to an external
pull-up resistor or to other external circuitry. The output of the
brownout reset detector will always preset the Idle Timer to a
value between 00F0 and 00FF (240 to 256 tC). At this time,
the internal reset will be generated.
greater than Vbor
.
Case 3 shows a dip in the supply where VCC drops below
Vbor, but not below 1.8V. On-chip RESET is asserted when
VCC goes below Vbor and tid starts as soon as the supply
The contents of data registers and RAM are unknown fol-
lowing the on-chip reset.
goes back above Vbor
.
The internal reset will not be turned off until the Idle Timer
underflows. The internal reset will perform the same func-
tions as external reset. The device is guaranteed to operate
at the specified frequency down to the specified brownout
voltage. After the underflow, the logic is designed such that
no additional internal resets occur as long as VCC remains
above the brownout voltage.
The device is relatively immune to short duration negative-
going VCC transients (glitches). It is essential that good
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22
Section 7.0 Power Saving Features. The low speed oscillator
utilizes the L0 and L1 port pins. References in the following
text to CKI will also apply to L0 and references to G7/CKO
will also apply to L1.
10.0 Functional Description
(Continued)
10.8.1 Oscillator
CKI is the clock input while G7/CKO is the clock generator
output to the crystal. An on-chip bias resistor connected
between CKI and CKO is provided to reduce system part
count. The value of the resistor is in the range of 0.5M to 2M
(typically 1.0M). Table 2 shows the component values re-
quired for various standard crystal values. Resistor R2 is
on-chip, for the high speed oscillator, and is shown for
reference. Figure 12 shows the crystal oscillator connection
diagram. A ceramic resonator of the required frequency may
be used in place of a crystal if the accuracy requirements are
not quite as strict.
20032714
FIGURE 11. Reset Circuit Using Power-On Reset
10.8 OSCILLATOR CIRCUITS
The device has two crystal oscillators to facilitate low power
operation while maintaining throughput when required. Fur-
ther information on the use of the two oscillators is found in
High Speed Oscillator
Low Speed Oscillator
20032716
20032715
FIGURE 12. Crystal Oscillator
C2 can be trimmed to obtain the desired frequency. C2
should be less than or equal to C1.
TABLE 2. Crystal Oscillator Configuration,
TA = 25˚C, VCC = 5V
Note: The low power design of the low speed oscillator
makes it extremely sensitive to board layout and load ca-
pacitance. The user should place the crystal and load ca-
pacitors within 1cm. of the device and must ensure that the
above equation for load capacitance is strictly followed. If
these conditions are not met, the application may have
problems with startup of the low speed oscillator.
CKI Freq.
(MHz)
10
R1 (kΩ) R2 (MΩ)
C1 (pF)
C2 (pF)
0
0
On Chip
On Chip
On Chip
On Chip
20
18
18
18
18
5
0
18–36
100
**
18–36
100–156
**
1
5.6
0
0.455
32.768
kHz*
TABLE 3. Startup Times
CKI Frequency
10 MHz
Startup Time
1–10 ms
*Applies to connection to low speed oscillator on port pins L0 and L1 only.
**See Note below.
The crystal and other oscillator components should be
placed in close proximity to the CKI and CKO pins to mini-
mize printed circuit trace length.
3.33 MHz
3–10 ms
1 MHz
3–20 ms
455 kHz
10–30 ms
2–5 sec
The values for the external capacitors should be chosen to
obtain the manufacturer’s specified load capacitance for the
crystal when combined with the parasitic capacitance of the
trace, socket, and package (which can vary from 0 to 8 pF).
The guideline in choosing these capacitors is:
32 kHz (low speed oscillator)
Manufacturer’s specified load cap = (C1 * C2) / (C1 + C2) +
Cparasitic
23
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10.9.3 ICNTRL Register (Address X'00E8)
10.0 Functional Description
(Continued)
Unused LPEN
Bit 7
T0PND
T0EN µWPND µWEN T1PNDB
T1ENB
Bit 0
10.8.2 Clock Doubler
This device contains a frequency doubler that doubles the
frequency of the oscillator selected to operate the main
microcontroller core. The details of how to select either the
high speed oscillator or low speed oscillator are described in,
Power Saving Features. When the high speed oscillator
connected to CKI operates at 10 MHz, the internal clock
frequency is 20 MHz, resulting in an instruction cycle time of
0.5 µs. When the 32 kHz oscillator connected to L0 and L1 is
selected, the internal clock frequency is 64 kHz, resulting in
an instruction cycle of 152.6 µs. The output of the clock
doubler is called MCLK and is referenced in many places
within this document.
The ICNTRL register contains the following bits:
LPEN Port Interrupt Enable
Wake-up/Interrupt)
T0PND Timer T0 Interrupt pending
T0EN Timer T0 Interrupt Enable (Bit 12 toggle)
µWPND MICROWIRE/PLUS interrupt pending
µWEN Enable MICROWIRE/PLUS interrupt
L
(Multi-Input
T1PNDB Timer T1 Interrupt Pending Flag for T1B capture
edge
T1ENB Timer T1 Interrupt Enable for T1B Input capture
edge
10.9 CONTROL REGISTERS
10.9.4 T2CNTRL Register (Address X'00C6)
10.9.1 CNTRL Register (Address X'00EE)
T2C3
Bit 7
T2C2
T2C1
T2C0
T2PNDA T2ENA T2PNDB T2ENB
Bit 0
T1C3
Bit 7
T1C2
T1C1
T1C0
MSEL
IEDG
SL1
SL0
Bit 0
The T2CNTRL register contains the following bits:
T2C3
T2C2
T2C1
T2C0
Timer T2 mode control bit
Timer T2 mode control bit
Timer T2 mode control bit
The Timer1 (T1) and MICROWIRE/PLUS control register
contains the following bits:
T1C3
T1C2
T1C1
T1C0
Timer T1 mode control bit
Timer T1 mode control bit
Timer T1 mode control bit
Timer T2 Start/Stop control in timer
modes 1 and 2, Timer T2 Underflow Interrupt
Pending Flag in timer mode 3
Timer T1 Start/Stop control in timer
modes 1 and 2. T1 Underflow Interrupt
Pending Flag in timer mode 3
T2PNDA Timer T2 Interrupt Pending Flag (Autoreload
RA in mode 1, T2 Underflow in mode 2, T2A
capture edge in mode 3)
MSEL
IEDG
Selects G5 and G4 as MICROWIRE/PLUS
signals SK and SO respectively
T2ENA
Timer T2 Interrupt Enable for Timer Underflow
or T2A Input capture edge
External interrupt edge polarity select
(0 = Rising edge, 1 = Falling edge)
T2PNDB Timer T2 Interrupt Pending Flag for T2B cap-
ture edge
SL1 & SL0 Select the MICROWIRE/PLUS clock divide
by (00 = 2, 01 = 4, 1x = 8)
T2ENB
Timer T2 Interrupt Enable for T2B Input capture
edge
10.9.2 PSW Register (Address X'00EF)
10.9.5 HSTCR Register (Address X'00AF)
HC
C
T1PNDA
T1ENA
EXPND
BUSY
EXEN
GIE
Reserved
T2HS
Bit 0
Bit 7
Bit 0
Bit 7
The PSW register contains the following select bits:
The HSTCR register contains the following bits:
T2HS Places Timer T2 in High Speed Mode.
HC
C
Half Carry Flag
Carry Flag
T1PNDA Timer T1 Interrupt Pending Flag (Autoreload RA
in mode 1, T1 Underflow in Mode 2, T1A capture
edge in mode 3)
T1ENA Timer T1 Interrupt Enable for Timer Underflow
or T1A Input capture edge
EXPND External interrupt pending
BUSY
EXEN
GIE
MICROWIRE/PLUS busy shifting flag
Enable external interrupt
Global interrupt enable (enables interrupts)
The Half-Carry flag is also affected by all the instructions that
affect the Carry flag. The SC (Set Carry) and R/C (Reset
Carry) instructions will respectively set or clear both the carry
flags. In addition to the SC and R/C instructions, ADC,
SUBC, RRC and RLC instructions affect the Carry and Half
Carry flags.
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24
executing from the flash memory or the Boot ROM. The user
must program the FLEX bit as appropriate for the applica-
tion. In the erased state, the FLEX bit = 0 and the device will
power-up executing from Boot ROM. When FLEX = 0, this
assumes that either the MICROWIRE/PLUS ISP routine or
external programming is being used to program the device. If
using the MICROWIRE/PLUS ISP routine, the software in
the boot ROM will monitor the MICROWIRE/PLUS for com-
mands to program the flash memory. When programming
the flash program memory is complete, the FLEX bit will
have to be programmed to a 1 and the device will have to be
reset, either by pulling external Reset to ground or by a
MICROWIRE/PLUS ISP EXIT command, before execution
from flash program memory will occur.
10.0 Functional Description
(Continued)
10.9.6 ITMR Register (Address X'00CF)
CCKS
EL
LSON HSON
Bit 7
DCEN
RSVD
ITSEL2
ITSEL1 ITSEL0
Bit 0
The ITMR register contains the following bits:
LSON
HSON
DCEN
Turns the low speed oscillator on or off.
Turns the high speed oscillator on or off.
Selects the high speed oscillator or the low
speed oscillator as the Idle Timer Clock.
CCKSEL Selects the high speed oscillator or the low
speed oscillator as the primary CPU clock.
If FLEX = 1, upon exiting Reset, the device will begin ex-
ecuting from location 0000 in the flash program memory. The
assumption, here, is that either the application is not using
ISP, is using MICROWIRE/PLUS ISP by jumping to it within
the application code, or is using a customized ISP routine. If
a customized ISP routine is being used, then it must be
programmed into the flash memory by means of the
MICROWIRE/PLUS ISP or external programming as de-
scribed in the preceding paragraph.
RSVD
This bit is reserved and must be 0.
ITSEL2 Idle Timer period select bit.
ITSEL1 Idle Timer period select bit.
ITSEL0 Idle Timer period select bit.
11.0 In-System Programming
11.3 REGISTERS
11.1 INTRODUCTION
There are six registers required to support ISP: Address
Register Hi byte (ISPADHI), Address Register Low byte
(ISPADLO), Read Data Register (ISPRD), Write Data Reg-
ister (ISPWR), Write Timing Register (PGMTIM), and the
Control Register (ISPCNTRL). The ISPCNTRL Register is
not available to the user.
This device provides the capability to program the program
memory while installed in an application board. This feature
is called In System Programming (ISP). It provides a means
of ISP by using the MICROWIRE/PLUS, or the user can
provide his own, customized ISP routine. The factory in-
stalled ISP uses the MICROWIRE/PLUS port. The user can
provide his own ISP routine that uses any of the capabilities
of the device, such as USART, parallel port, etc.
11.3.1 ISP Address Registers
The address registers (ISPADHI & ISPADLO) are used to
specify the address of the byte of data being written or read.
For page erase operations, the address of the beginning of
the page should be loaded. For mass erase operations,
0000 must be placed into the address registers. When read-
ing the Option register, FFFF (hex) should be placed into the
address registers. Registers ISPADHI and ISPADLO are
cleared to 00 on Reset. These registers can be loaded from
either flash program memory or Boot ROM and must be
maintained for the entire duration of the operation.
11.2 FUNCTIONAL DESCRIPTION
The organization of the ISP feature consists of the user flash
program memory, the factory boot ROM, and some registers
dedicated to performing the ISP function. See Figure 13 for
a simplified block diagram. The factory installed ISP that
uses MICROWIRE/PLUS is located in the Boot ROM. The
size of the Boot ROM is 1k bytes and also contains code to
facilitate in system emulation capability. If a user chooses to
write his own ISP routine, it must be located in the flash
program memory.
Note: The actual memory address of the Option Register is
0x3FFF (hex), however the MICROWIRE/PLUS ISP routines
require the address FFFF (hex) to be used to read the
Option Register when the Flash Memory is secured.
TABLE 4. High Byte of ISP Address
ISPADHi
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Addr 15 Addr 14 Addr 13 Addr 12 Addr 11 Addr 10 Addr 9 Addr 8
TABLE 5. Low Byte of ISP Address
ISPADLO
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Addr 7
Addr 6
Addr 5
Addr 4
Addr 3
Addr 2
Addr 1 Addr 0
20032717
11.3.2 ISP Read Data Register
The Read Data Register (ISPRD) contains the value read
back from a read operation. This register can be accessed
from either flash program memory or Boot ROM. This regis-
ter is undefined on Reset.
FIGURE 13. Block Diagram of ISP
As described in Section 10.5 OPTION REGISTER, there is a
bit, FLEX, that controls whether the device exits RESET
25
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11.3.4 ISP Write Timing Register
11.0 In-System Programming
The Write Timing Register (PGMTIM) is used to control the
width of the timing pulses for write and erase operations. The
value to be written into this register is dependent on the
frequency of CKI and is shown in Table 8. This register must
be written before any write or erase operation can take
place. It only needs to be loaded once, for each value of CKI
frequency. This register can be loaded from either flash
program memory or Boot ROM and must be maintained for
the entire duration of the operation. The MICROWIRE/PLUS
ISP routine that is resident in the boot ROM requires that this
Register be defined prior to any access to the Flash memory.
Refer to Section 11.7 MICROWIRE/PLUS ISP for more in-
formation on available ISP commands. On Reset, the PG-
MTIM register is loaded with the value that corresponds to
10 MHz frequency for CKI.
(Continued)
TABLE 6. ISP Read Data Register
ISPRD
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
11.3.3 ISP Write Data Register
The Write Data Register (ISPWR) contains the data to be
written into the specified address. This register is undeter-
mined on Reset. This register can be accessed from either
flash program memory or Boot ROM. The Write Data register
must be maintained for the entire duration of the operation.
TABLE 7. ISP Write Data Register
ISPWR
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
TABLE 8. PGMTIM Register Format
PGMTIM
Register Bit
CKI Frequency Range
7
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
R
6
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
5
0
4
0
3
0
2
0
1
0
0
1
25 kHz–33.3 kHz
37.5 kHz–50 kHz
50 kHz–66.67 kHz
62.5 kHz–83.3 kHz
75 kHz–100 kHz
0
0
0
0
1
0
0
0
0
0
1
1
0
0
0
1
0
0
0
0
0
1
0
1
0
0
0
1
1
1
100 kHz–133 kHz
112.5 kHz–150 kHz
150 kHz–200 kHz
200 kHz–266.67 kHz
225 kHz–300 kHz
300 kHz–400 kHz
375 kHz–500 kHz
500 kHz–666.67 kHz
600 kHz–800 kHz
800 kHz–1.067 MHz
1 MHz–1.33 MHz
1.125 MHz–1.5 MHz
1.5 MHz–2 MHz
0
0
1
0
0
0
0
0
1
0
1
1
0
0
1
1
1
1
0
1
0
0
0
1
0
1
0
1
1
1
0
1
1
1
0
1
1
0
0
1
1
1
1
0
1
1
1
1
1
1
1
1
1
1
0
0
0
1
1
1
0
0
1
0
0
0
0
0
1
0
1
1
0
0
1
1
1
1
2 MHz–2.67 MHz
2.625 MHz–3.5 MHz
3.5 MHz–4.67 MHz
4.5 MHz–6 MHz
0
1
0
1
0
0
0
1
1
0
1
1
1
0
0
0
1
1
1
0
1
1
1
1
6 MHz–8 MHz
1
1
1
0
1
1
7.5 MHz–10 MHz
R/W
R/W
R/W
R/W
R/W
R/W
R/W
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26
memory and reprogram it. If the device is subsequently reset
before the Flex bit has been erased by specific Page Erase
or Mass Erase ISP commands, execution will start from
location 0000 in the Flash program memory. The high volt-
age (2 x VCC) on G6 will not erase either the Flex or the
Security bit in the Option Register. The Security bit, if set,
can only be erased by a Mass Erase of the entire contents of
the Flash Memory unless under the control of User ISP
routines in the Application Program.
11.0 In-System Programming
(Continued)
11.4 MANEUVERING BACK AND FORTH BETWEEN
FLASH MEMORY AND BOOT ROM
When using ISP, at some point, it will be necessary to
maneuver between the flash program memory and the Boot
ROM, even when using customized ISP routines. This is
because it’s not possible to execute from the flash program
memory while it’s being programmed.
While the G6 pin is at high voltage, the Load Clock will be
output onto G5, which will look like an SK clock to the
MICROWIRE/PLUS routine executing in slave mode. How-
ever, when G6 is at high voltage, the G6 input will also look
like a logic 1. The MICROWIRE/PLUS routine in Boot ROM
monitors the G6 input, waits for it to go low, debounces it,
and then enables the ISP routine. CAUTION: The Load clock
on G5 could be in conflict with the user’s external SK. It is up
to the user to resolve this conflict, as this condition is con-
sidered a minor issue that’s only encountered during soft-
ware development. The user should also be cautious of
the high voltage applied to the G6 pin. This high voltage
could damage other circuitry connected to the G6 pin
(e.g. the parallel port of a PC). The user may wish to
disconnect other circuitry while G6 is connected to the high
voltage.
Two instructions are available to perform the jumping back
and forth: Jump to Boot (JSRB) and Return to Flash (RETF).
The JSRB instruction is used to jump from flash memory to
Boot ROM, and the RETF is used to return from the Boot
ROM back to the flash program memory. See Section 19.0
Instruction Set for specific details on the operation of these
instructions.
The JSRB instruction must be used in conjunction with the
Key register. This is to prevent jumping to the Boot ROM in
the event of run-away software. For the JSRB instruction to
actually jump to the Boot ROM, the Key bit must be set. This
is done by writing the value shown in Table 9 to the Key
register. The Key is a 6 bit key and if the key matches, the
KEY bit will be set for 8 instruction cycles. The JSRB instruc-
tion must be executed while the KEY bit is set. If the KEY
does not match, then the KEY bit will not be set and the
JSRB will jump to the specified location in the flash memory.
In emulation mode, if a breakpoint is encountered while the
KEY is set, the counter that counts the instruction cycles will
be frozen until the breakpoint condition is cleared. If an
interrupt occurs while the key is set, the key will expire
before interrupt service is complete. It is recommended
that the software globally disable interrupts before set-
ting the key and re-enable interrupts on completion of
Boot ROM execution. The Key register is a memory
mapped register. Its format when writing is shown in Table 9.
VCC must be valid and stable before high voltage is applied
to G6.
The correct sequence to be used to force execution from
Boot ROM is :
1. Disconnect G6 from the source of data for MICROWIRE/
PLUS ISP.
2. Apply VCC to the device.
3. Pull RESET Low.
4. After VCC is valid and stable, connect a voltage between
2 x VCC and VCC+7V to the G6 pin. Ensure that the rise
time of the high voltage on G6 is slower than the mini-
mum in the Electrical Specifications. Figure 14 shows a
TABLE 9. KEY Register Write Format
possible circuit dliagram for implementing the 2 x VCC
.
Be aware of the typical input current on the G6 pin when
the high voltage is applied. The resistor used in the RC
network, and the high voltage used, should be chosen to
keep the high voltage at the G6 pin between 2 x VCC and
VCC+7V.
KEY When Writing
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
1
0
0
1
1
0
X
X
Bits 7–2: Key value that must be written to set the KEY bit.
Bits 1–0: Don’t care.
5. Pull RESET High.
6. After a delay of at least three instruction cycles, remove
the high voltage from G6.
11.5 FORCED EXECUTION FROM BOOT ROM
When the user is developing a customized ISP routine, code
lockups due to software errors may be encountered. The
normal, and preferred, method to recover from these condi-
tions is to reprogram the device with the corrected code by
either an external parallel programmer or the emulation
tools. As a last resort, when this equipment is not available,
there is a hardware method to get out of these lockups and
force execution from the Boot ROM MICROWIRE/PLUS
routine. The customer will then be able to erase the Flash
Memory code and start over.
20032766
The method to force this condition is to drive the G6 pin to
high voltage (2 x VCC) and activate Reset. The high voltage
condition on G6 must not be applied before VCC is valid and
stable, and must be held for at least 3 instruction cycles
longer than Reset is active. This special condition will by-
pass checking the state of the Flex bit in the Option Register
and will start execution from location 0000 in the Boot ROM.
In this state, the user can input the appropriate commands,
using MICROWIRE/PLUS, to erase the flash program
FIGURE 14. Circuit Diagram for Implementing the 2 x
VCC
27
www.national.com
Manual, available from the same web site. This document
includes details of command format and delays necessary
between command bytes.
11.0 In-System Programming
(Continued)
11.6 RETURN TO FLASH MEMORY WITHOUT
HARDWARE RESET
The MICROWIRE/PLUS ISP supports the following features
and commands:
After programming the entire program memory, including
options, it is necessary to exit the Boot ROM and return to
the flash program memory for program execution. Upon
receipt and completion of the EXIT command through the
MICROWIRE/PLUS ISP, the ISP code will reset the part and
begin execution from the flash program memory as de-
scribed in the Reset section. This assumes that the FLEX bit
in the Option register was programmed to 1.
•
Write a value to the ISP Write Timing Register. NOTE:
This must be the first command after entering
MICROWIRE/PLUS ISP mode.
•
•
•
•
•
•
•
•
Erase the entire flash program memory (mass erase).
Erase a page at a specified address.
Read Option register.
Read a byte from a specified address.
Write a byte to a specified address.
11.7 MICROWIRE/PLUS ISP
Read multiple bytes starting at a specified address.
Write multiple bytes starting at a specified address.
Exit ISP and return execution to flash program memory.
National Semiconductor provides a program, which is avail-
able from our web site at www.national.com/cop8, that is
capable of programming a device from the parallel port of a
PC. The software accepts manually input commands and is
capable of downloading standard Intel HEX Format files.
The following table lists the MICROWIRE/PLUS ISP com-
mands and provides information on required parameters and
return values.
Users who wish to write their own MICROWIRE/PLUS ISP
host software should refer to the COP8 FLASH ISP User
TABLE 10. MICROWIRE/PLUS ISP Commands
Command
Value (Hex)
0x3B
Command
PGMTIM_SET
Function
Parameters
Return Data
Write Pulse Timing
Register
Value
N/A
N/A
PAGE_ERASE
MASS_ERASE
READ_BYTE
Page Erase
0xB3
0xBF
0x1D
Starting Address of
Page
Mass Erase
Read Byte
Confirmation Code
N/A (The entire Flash
Memory will be erased)
Address High, Address Data Byte if Security not
Low
set. 0xFF if Security set.
Option Register if address
= 0xFFFF, regardless of
Security
BLOCKR
Block Read
0xA3
Address High, Address n Data Bytes if Security
Low, Byte Count (n)
High, Byte Count (n)
Low
not set.
n Bytes of 0xFF if
Security set.
0 ≤ n ≤ 32767
WRITE_BYTE
BLOCKW
Write Byte
Block Write
0x71
0x8F
Address High, Address N/A
Low, Data Byte
Address High, Address N/A
Low, Byte Count (0 ≤ n
≤ 16), n Data Bytes
EXIT
EXIT
N/A
0xD3
N/A
N/A (Device will Reset)
N/A
INVALID
Any other invalid
command will be
ignored
Note: The user must ensure that Block Writes do not cross a 64 byte boundary within one operation.
11.8 USER ISP AND VIRTUAL E2
•
Erase the entire flash program memory (mass erase).
NOTE: Execution of this command will force the device
into the MICROWIRE/PLUS ISP mode.
The following commands will support transferring blocks of
data from RAM to flash program memory, and vice-versa.
The user is expected to enforce application security in this
case.
•
•
•
Erase a page of flash memory at a specified address.
Read a byte from a specified address.
Write a byte to a specified address.
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28
mand entry point is used as an argument to the JSRB
instruction. Table 12 lists the Ram locations and Peripheral
Registers, used for User ISP and Virtual E2, and their ex-
pected contents. Please refer to the COP8 FLASH ISP User
Manual for additional information and programming ex-
amples on the use of User ISP and Virtual E2.
11.0 In-System Programming
(Continued)
•
Copy a block of data from RAM into flash program
memory.
•
Copy a block of data from program flash memory to RAM.
The following table lists the User ISP/Virtual E2 commands,
required parameters and return data, if applicable. The com-
29
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11.0 In-System Programming (Continued)
TABLE 11. User ISP/Virtual E2 Entry Points
Command/
Label
Command
Entry Point
Function
Parameters
Return Data
cpgerase
Page Erase
0x17
Register ISPADHI is loaded by the user N/A (A page of memory beginning at
with the high byte of the address.
Register ISPADLO is loaded by the
user with the low byte of the address.
Accumulator A contains the
ISPADHI, ISPADLO will be erased)
cmserase
creadbf
Mass Erase
Read Byte
0x1A
0x11
N/A (The entire Flash Memory will be
erased)
confirmation key 0x55.
Register ISPADHI is loaded by the user Data Byte in Register ISPRD.
with the high byte of the address.
Register ISPADLO is loaded by the
user with the low byte of the address.
cblockr
Block Read
0x26
Register ISPADHI is loaded by the user n Data Bytes, Data will be returned
with the high byte of the address.
Register ISPADLO is loaded by the
user with the low byte of the address.
X pointer contains the beginning RAM
address where the result(s) will be
returned.
beginning at a location pointed to by
the RAM address in X.
Register BYTECOUNTLO contains the
number of n bytes to read
(0 ≤ n ≤ 255). It is up to the user to
setup the segment register.
cwritebf
cblockw
Write Byte
Block Write
0x14
0x23
Register ISPADHI is loaded by the user N/A
with the high byte of the address.
Register ISPADLO is loaded by the
user with the low byte of the address.
Register ISPWR contains the Data
Byte to be written.
Register ISPADHI is loaded by the user N/A
with the high byte of the address.
Register ISPADLO is loaded by the
user with the low byte of the address.
Register BYTECOUNTLO contains the
number of n bytes to write (0 ≤ n ≤ 16).
The combination of the
BYTECOUNTLO and the ISPADLO
registers must be set such that the
operation will not cross a 64 byte
boundary.
X pointer contains the beginning RAM
address of the data to be written.
It is up to the user to setup the
segment register.
exit
EXIT
0x62
0x00
N/A
N/A
N/A (Device will Reset)
uwisp
MICROWIRE/
PLUS
N/A (Device will be in
MICROWIRE/PLUS ISP Mode. Must be
terminated by MICROWIRE/PLUS ISP
EXIT command which will reset the
device)
ISP Start
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30
11.0 In-System Programming (Continued)
TABLE 12. Register and Bit Name Definitions
Register
Name
RAM
Location
0xA9
Purpose
ISPADHI
High byte of Flash Memory Address
Low byte of Flash Memory Address
ISPADLO
ISPWR
0xA8
The user must store the byte to be written into this register before jumping into the
write byte routine.
0xAB
ISPRD
Data will be returned to this register after the read byte routine execution.
The ISPKEY Register is required to validate the JSRB instruction and must be loaded
within 6 instruction cycles before the JSRB.
0xAA
0xE2
ISPKEY
BYTECOUNTLO
PGMTIM
Holds the count of the number of bytes to be read or written in block operations.
Write Timing Register. This register must be loaded, by the user, with the proper value
before execution of any USER ISP Write or Erase operation. Refer to Table 8 for the
correct value.
0xF1
0xE1
Confirmation Code
KEY
The user must place this code in the accumulator before execution of a Flash Memory
Mass Erase command.
A
Must be transferred to the ISPKEY register before execution of a JSRB instruction.
0x98
11.9 RESTRICTIONS ON SOFTWARE WHEN CALLING
ISP ROUTINES IN BOOT ROM
the same location in Flash memory. Two writes to
the same location without an intervening erase will
produce unpredicatable results including possible
disturbance of unassociated locations.
1. The hardware will disable interrupts from occurring. The
hardware will leave the GIE bit in its current state, and if
set, the hardware interrupts will occur when execution is
returned to Flash Memory. Subsequent interrupts, dur-
ing ISP operation, from the same interrupt source will be
lost. Interrupts may occur between setting the KEY
and executing the JSRB instruction. In this case, the
KEY will expire before the JSRB is executed. It is,
therefore, recommended that the software globally
disable interrupts before setting the Key.
11.10 FLASH MEMORY DURABILITY CONSIDERATIONS
The endurance of the Flash Memory (number of possible
Erase/Write cycles) is a function of the erase time and the
lowest temperature at which the erasure occurs. If the device
is to be used at low temperature, additional erase operations
can be used to extend the erase time. The user can deter-
mine how many times to erase a page based on what
endurance is desired for the application (e.g. four page
erase cycles, each time a page erase is done, may be
required to achieve the typical 100k Erase/Write cycles in an
application which may be operating down to 0˚C). Also, the
customer can verify that the entire page is erased, with
software, and request additional erase operations if desired.
2. The security feature in the MICROWIRE/PLUS ISP is
guaranteed by software and not hardware. When ex-
ecuting the MICROWIRE/PLUS ISP routine, the security
bit is checked prior to performing all instructions. Only
the mass erase command, write PGMTIM register, and
reading the Option register is permitted within the
MICROWIRE/PLUS ISP routine. When the user is per-
forming his own ISP, all commands are permitted. The
entry points from the user’s ISP code do not check for
security. It is the burden of the user to guarantee his own
security. See the Security bit description in Section 10.5
OPTION REGISTER for more details on security.
TABLE 13. Typical Flash Memory Endurance
Low End of Operating Temp Range
Erase
>
25˚C
−40˚C
−20˚C
0˚C
25˚C
Time
1 ms
2 ms
3 ms
4 ms
5 ms
6 ms
7 ms
8 ms
3. When using any of the ISP functions in Boot ROM, the
ISP routines will service the WATCHDOG within the
selected upper window. Upon return to flash memory,
the WATCHDOG is serviced, the lower window is en-
abled, and the user can service the WATCHDOG any-
time following exit from Boot ROM, but must service it
within the selected upper window to avoid a WATCH-
DOG error.
60k
60k
60k
60k
70k
80k
90k
100k
60k
60k
60k
60k
70k
80k
90k
100k
60k
60k
100k
100k
100k
100k
100k
100k
100k
100k
100k
100k
100k
100k
100k
100k
100k
100k
60k
100k
100k
100k
100k
100k
4. Block Writes can start anywhere in the page of Flash
memory, but cannot cross half page or full page bound-
aries.
5. The user must ensure that a page erase or a mass
erase is executed between two consecutive writes to
31
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•
•
•
WATCHDOG logic (See WATCHDOG description)
Start up delay out of the HALT mode
Start up delay from BOR
12.0 Timers
The device contains a very versatile set of timers (T0, T1 and
T2). Timers T1 and T2 and associated autoreload/capture
registers power up containing random data.
Figure 15 is a functional block diagram showing the structure
of the IDLE Timer and its associated interrupt logic.
12.1 TIMER T0 (IDLE TIMER)
Bits 11 through 15 of the ITMR register can be selected for
triggering the IDLE Timer interrupt. Each time the selected
bit underflows (every 4k, 8k, 16k, 32k or 64k selected
clocks), the IDLE Timer interrupt pending bit T0PND is set,
thus generating an interrupt (if enabled), and bit 6 of the Port
G data register is reset, thus causing an exit from the IDLE
mode if the device is in that mode.
The device supports applications that require maintaining
real time and low power with the IDLE mode. This IDLE
mode support is furnished by the IDLE Timer T0, which is a
16-bit timer. The user cannot read or write to the IDLE Timer
T0, which is a count down timer.
As described in Section 13.0 Power Saving Features, the
clock to the IDLE Timer depends on which mode the device
is in. If the device is in High Speed mode, the clock to the
IDLE Timer is the instruction cycle clock (one-fifth of the CKI
frequency). If the device is in Dual Clock mode or Low Speed
mode, the clock to the IDLE Timer is the 32 kHz clock. For
the remainder of this section, the term “selected clock” will
refer to the clock selected by the Power Save mode of the
device. During Dual Clock and Low Speed modes, the divide
by 10 that creates the instruction cycle clock is disabled, to
minimize power consumption.
In order for an interrupt to be generated, the IDLE Timer
interrupt enable bit T0EN must be set, and the GIE (Global
Interrupt Enable) bit must also be set. The T0PND flag and
T0EN bit are bits 5 and 4 of the ICNTRL register, respec-
tively. The interrupt can be used for any purpose. Typically, it
is used to perform a task upon exit from the IDLE mode. For
more information on the IDLE mode, refer to Section 13.0
Power Saving Features.
The Idle Timer period is selected by bits 0–2 of the ITMR
register Bit 3 of the ITMR Register is reserved and should
not be used as a software flag. Bits 4 through 7 of the ITMR
Register are used by the dual clock and are described in
Section 13.0 Power Saving Features.
In addition to its time base function, the Timer T0 supports
the following functions:
•
Exit out of the Idle Mode (See Idle Mode description)
20032718
FIGURE 15. Functional Block Diagram for Idle Timer T0
The ITSEL bits of the ITMR register are cleared on Reset
and the Idle Timer period is reset to 4,096 instruction cycles.
TABLE 14. Idle Timer Window Length
Idle Timer Period
ITSEL2 ITSEL1 ITSEL0
High Speed
Mode
Dual Clock or
12.1.1 ITMR Register
CCK
Low Speed Mode
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
4,096 inst. cycles
8,192 inst. cycles
16,384 inst. cycles
32,768 inst. cycles
65,536 inst. cycles
0.125 seconds
0.25 seconds
0.5 seconds
1 second
LSON HSON DCEN
RSVD ITSEL2 ITSEL1 ITSEL0
Bit 3 Bit 2 Bit 1 Bit 0
SEL
Bit 7
Bit 6
Bit 5
Bit 4
Bits 7–4: Described in Section 13.0 Power Saving
Features.
2 seconds
Note: Documentation for previous COP8 devices, which in-
cluded the Programmable Idle Timer, recommended the user
write zero to the high order bits of the ITMR Register. If
Reserved - Undefined
Reserved - Undefined
Reserved - Undefined
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32
and the reload values are automatically written into the timer
when it counts down through 0, generating interrupt on each
reload. Under software control and with minimal overhead,
the PWM outputs are useful in controlling motors, triacs, the
intensity of displays, and in providing inputs for data acqui-
sition and sine wave generators.
12.0 Timers (Continued)
existing programs are updated to use this device, writing
zero to these bits will cause the device to reset (see Section
13.0 Power Saving Features).
RSVD: This bit is reserved and must be set to 0.
In this mode, the timer Tx counts down at a fixed rate of tC
(T2 may be selected to operate from MCLK). Upon every
underflow the timer is alternately reloaded with the contents
of supporting registers, RxA and RxB. The very first under-
flow of the timer causes the timer to reload from the register
RxA. Subsequent underflows cause the timer to be reloaded
from the registers alternately beginning with the register
RxB.
ITSEL2:0: Selects the Idle Timer period as described in
Table 14, Idle Timer Window Length.
Any time the IDLE Timer period is changed there is the
possibility of generating a spurious IDLE Timer interrupt by
setting the T0PND bit. The user is advised to disable IDLE
Timer interrupts prior to changing the value of the ITSEL bits
of the ITMR Register and then clear the T0PND bit before
attempting to synchronize operation to the IDLE Timer.
Figure 16 shows a block diagram of the timer in PWM mode.
12.2 TIMER T1 AND TIMER T2
The underflows can be programmed to toggle the TxA output
pin. The underflows can also be programmed to generate
interrupts.
The device has a set of two powerful timer/counter blocks,
T1 and T2. Since T1 and T2 are identical, except for the high
speed operation of T2, all comments are equally applicable
to either of the two timer blocks which will be referred to as
Tx. Differences between the timers will be specifically noted.
Underflows from the timer are alternately latched into two
pending flags, TxPNDA and TxPNDB. The user must reset
these pending flags under software control. Two control
enable flags, TxENA and TxENB, allow the interrupts from
the timer underflow to be enabled or disabled. Setting the
timer enable flag TxENA will cause an interrupt when a timer
underflow causes the RxA register to be reloaded into the
timer. Setting the timer enable flag TxENB will cause an
interrupt when a timer underflow causes the RxB register to
be reloaded into the timer. Resetting the timer enable flags
will disable the associated interrupts.
Each timer block consists of a 16-bit timer, Tx, and two
supporting 16-bit autoreload/capture registers, RxA and
RxB. Each timer block has two pins associated with it, TxA
and TxB. The pin TxA supports I/O required by the timer
block, while the pin TxB is an input to the timer block. The
timer block has three operating modes: Processor Indepen-
dent PWM mode, External Event Counter mode, and Input
Capture mode.
Either or both of the timer underflow interrupts may be
enabled. This gives the user the flexibility of interrupting
once per PWM period on either the rising or falling edge of
the PWM output. Alternatively, the user may choose to inter-
rupt on both edges of the PWM output.
The control bits TxC3, TxC2, and TxC1 allow selection of the
different modes of operation.
12.2.1 Timer Operating Speeds
Each of the Tx timers, except T1, have the ability to operate
at either the instruction cycle frequency (low speed) or the
internal clock frequency (MCLK). For 10 MHz CKI, the in-
struction cycle frequency is 2 MHz and the internal clock
frequency is 20 MHz. This feature is controlled by the High
Speed Timer Control Register, HSTCR. Its format is shown
below. To place a timer, Tx, in high speed mode, set the
appropriate TxHS bit to 1. For low speed operation, clear the
appropriate TxHS bit to 0. This register is cleared to 00 on
Reset.
HSTCR
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0
0
0
0
0
0
0
T2HS
12.2.2 Mode 1. Processor Independent PWM Mode
One of the timer’s operating modes is the Processor Inde-
pendent PWM mode. In this mode, the timers generate a
“Processor Independent” PWM signal because once the
timer is set up, no more action is required from the CPU
which translates to less software overhead and greater
throughput. The user software services the timer block only
when the PWM parameters require updating. This capability
is provided by the fact that the timer has two separate 16-bit
reload registers. One of the reload registers contains the
“ON” time while the other holds the “OFF” time. By contrast,
a microcontroller that has only a single reload register re-
quires an additional software to update the reload value
(alternate between the on-time/off-time).
20032719
FIGURE 16. Timer in PWM Mode
If Timer T2 is used in High Speed PWM mode and an SBIT
or RBIT instruction operates on any other bit of the PORT L
Data Register, the PWM output may appear to miss a toggle
and thus be inverted. If the timer causes the PWM output to
toggle in the middle of an SBIT or RBIT operation on the
PORTLD Register, the PWM output may be set back to its
state before the output toggle by the operation of the SBIT/
RBIT. This can have the effect of generating a shortened
pulse (less than one instruction cycle in width) on the PWM
The timer can generate the PWM output with the width and
duty cycle controlled by the values stored in the reload
registers. The reload registers control the countdown values
33
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12.0 Timers (Continued)
output and inverting the PWM duty cycle. If the PWM Timer
is used in low speed mode or if the PWM output toggle is
synchronous with the end of the instruction cycle, this prob-
lem is not seen. The following figure illustrates the PWM
output when the failure is seen. The user should be aware of
the state of Timer T2 before any SBIT or RBIT instructions
are executed which operate on the PORTLD register. If the
PWM output is close to toggling, the user should delay the
SBIT or RBIT instruction. The following program sequence
works to delay the operation. The user may wish to experi-
ment with other sequences to see which best fits the appli-
cation and to make sure that the time between the comple-
tion of the tests and the modification of PORTLD is not too
long.
LD B,#TMR2HI ;POINT B TO THE TIMER
LD A,[B-] ;GET THE VALUE IN THE TIMER
IFGT A,#0 ;IF NON ZERO
JP GOOD ;WE HAVE TIME
20032720
WAIT: IFBIT 6,[B] ;TEST BIT 6 OF THE TIMER
JP GOOD ;TIME TO GET IT DONE SAFELY
JP WAIT ;WAIT A WHILE
FIGURE 17. Timer in External Event Counter Mode
GOOD: SBIT 2,PORTLD ;GO AHEAD AND SET THE
⇒ BIT
The above program uses specific bits of the port for expla-
nation purposes only. The above program uses the SBIT
instruction by way of example. The RBIT instruction will have
the same effect. The above sequence will not work properly
for PWM times shorter than 64 CPU Clock cycles.
12.2.4 Mode 3. Input Capture Mode
The device can precisely measure external frequencies or
time external events by placing the timer block, Tx, in the
input capture mode. In this mode, the reload registers serve
as independent capture registers, capturing the contents of
the timer when an external event occurs (transition on the
timer input pin). The capture registers can be read while
maintaining count, a feature that lets the user measure
elapsed time and time between events. By saving the timer
value when the external event occurs, the time of the exter-
nal event is recorded. Most microcontrollers have a latency
time because they cannot determine the timer value when
the external event occurs. The capture register eliminates
the latency time, thereby allowing the applications program
to retrieve the timer value stored in the capture register.
12.2.3 Mode 2. External Event Counter Mode
This mode is quite similar to the processor independent
PWM mode described above. The main difference is that the
timer, Tx, is clocked by the input signal from the TxA pin after
synchronization to the appropriate internal clock (tC or
MCLK). The Tx timer control bits, TxC3, TxC2 and TxC1
allow the timer to be clocked either on a positive or negative
edge from the TxA pin. Underflows from the timer are latched
into the TxPNDA pending flag. Setting the TxENA control flag
will cause an interrupt when the timer underflows.
In this mode, the timer Tx is constantly running at the fixed tC
or MCLK rate. The two registers, RxA and RxB, act as
capture registers. Each register also acts in conjunction with
a pin. The register RxA acts in conjunction with the TxA pin
and the register RxB acts in conjunction with the TxB pin.
In this mode the input pin TxB can be used as an indepen-
dent positive edge sensitive interrupt input if the TxENB
control flag is set. The occurrence of a positive edge on the
TxB input pin is latched into the TxPNDB flag.
The timer value gets copied over into the register when a
trigger event occurs on its corresponding pin after synchro-
nization to the appropriate internal clock (tC or MCLK). Con-
trol bits, TxC3, TxC2 and TxC1, allow the trigger events to be
specified either as a positive or a negative edge. The trigger
condition for each input pin can be specified independently.
Figure 17 shows a block diagram of the timer in External
Event Counter mode.
Note: The PWM output is not available in this mode since the
TxA pin is being used as the counter input clock.
The trigger conditions can also be programmed to generate
interrupts. The occurrence of the specified trigger condition
on the TxA and TxB pins will be respectively latched into the
pending flags, TxPNDA and TxPNDB. The control flag
TxENA allows the interrupt on TxA to be either enabled or
disabled. Setting the TxENA flag enables interrupts to be
generated when the selected trigger condition occurs on the
TxA pin. Similarly, the flag TxENB controls the interrupts
from the TxB pin.
Underflows from the timer can also be programmed to gen-
erate interrupts. Underflows are latched into the timer TxC0
pending flag (the TxC0 control bit serves as the timer under-
flow interrupt pending flag in the Input Capture mode). Con-
sequently, the TxC0 control bit should be reset when enter-
ing the Input Capture mode. The timer underflow interrupt is
enabled with the TxENA control flag. When a TxA interrupt
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34
TxC2
TxC1
TxC0
Timer mode control
Timer mode control
12.0 Timers (Continued)
occurs in the Input Capture mode, the user must check both
the TxPNDA and TxC0 pending flags in order to determine
whether a TxA input capture or a timer underflow (or both)
caused the interrupt.
Timer Start/Stop control in Modes 1 and 2 (Pro-
cessor Independent PWM and External Event
Counter), where 1 = Start, 0 = Stop
Timer Underflow Interrupt Pending Flag in Mode
3 (Input Capture)
Figure 18 shows a block diagram of the timer T1 in Input
Capture mode. T2 is identical to T1.
TxPNDA Timer Interrupt Pending Flag
TxENA Timer Interrupt Enable Flag
1 = Timer Interrupt Enabled
0 = Timer Interrupt Disabled
TxPNDB Timer Interrupt Pending Flag
TxENB Timer Interrupt Enable Flag
1 = Timer Interrupt Enabled
0 = Timer Interrupt Disabled
The timer mode control bits (TxC3, TxC2 and TxC1) are
detailed in Table 15, Timer Operating Modes.
When the high speed timers are counting in high speed
mode, directly altering the contents of the timer upper or
lower registers, the PWM outputs or the reload registers is
not recommended. Bit operations can be particularly prob-
lematic. Since any of these six registers or the PWM outputs
can change as many as ten times in a single instruction
cycle, performing an SBIT or RBIT operation with the timer
running can produce unpredictable results. The recom-
mended procedure is to stop the timer, perform any changes
to the timer, the PWM outputs or reload register values, and
then re-start the timer. This warning does not apply to the
timer control register. Any type of read/write operation, in-
cluding SBIT and RBIT may be performed on this register in
any operating mode.
20032721
FIGURE 18. Timer in Input Capture Mode
12.3 TIMER CONTROL FLAGS
The control bits and their functions are summarized below.
TxC3
Timer mode control
TABLE 15. Timer Operating Modes
Interrupt A
Interrupt B
Source
Timer Counts
On
Mode
TxC3
TxC2
TxC1
Description
Source
Autoreload RA
Autoreload RA
Timer
1
1
0
0
0
0
1
0
0
PWM: TxA Toggle
Autoreload RB
Autoreload RB
Pos. TxB Edge
tC or MCLK
tC or MCLK
TxA Pos. Edge
1
2
PWM: No TxA Toggle
External Event Counter
Underflow
Timer
0
0
0
1
1
0
External Event Counter
Pos. TxB Edge
Pos. TxB Edge
TxA Neg. Edge
tC or MCLK
Underflow
Pos. TxA Edge
or Timer
Captures:
TxA Pos. Edge
TxB Pos. Edge
Captures:
Underflow
Pos. TxA
1
0
1
1
1
1
0
1
1
Neg. TxB
Edge
tC or MCLK
tC or MCLK
tC or MCLK
TxA Pos. Edge
TxB Neg. Edge
Captures:
Edge or Timer
Underflow
Neg. TxA
3
Pos. TxB
Edge
TxA Neg. Edge
TxB Pos. Edge
Captures:
Edge or Timer
Underflow
Neg. TxA
Neg. TxB
Edge
TxA Neg. Edge
TxB Neg. Edge
Edge or Timer
Underflow
35
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ing modes are: High Speed, Dual Clock, and Low Speed.
Within each operating mode, the two power save modes are:
HALT and IDLE. In the HALT mode of operation, all micro-
controller activities are stopped and power consumption is
reduced to a very low level. In this device, the HALT mode is
enabled and disabled by a bit in the Option register. The
IDLE mode is similar to the HALT mode, except that certain
sections of the device continue to operate, such as: the
on-board oscillator, the IDLE Timer (Timer T0), and the Clock
Monitor. This allows real time to be maintained. During
power save modes of operation, all on board RAM, registers,
I/O states and timers (with the exception of T0) are unal-
tered.
13.0 Power Saving Features
Today, the proliferation of battery-operated applications has
placed new demands on designers to drive power consump-
tion down. Battery operated systems are not the only type of
applications demanding low power. The power budget con-
straints are also imposed on those consumer/industrial ap-
plications where well regulated and expensive power supply
costs cannot be tolerated. Such applications rely on low cost
and low power supply voltage derived directly from the
“mains” by using voltage rectifier and passive components.
Low power is demanded even in automotive applications,
due to increased vehicle electronics content. This is required
to ease the burden from the car battery. Low power 8-bit
microcontrollers supply the smarts to control battery-
operated, consumer/industrial, and automotive applications.
Two oscillators are used to support the three different oper-
ating modes. The high speed oscillator refers to the oscillator
connected to CKI and the low speed oscillator refers to the
32 kHz oscillator connected to pins L0 & L1. When using L0
and L1 for the low speed oscillator, the user must ensure that
the L0 and L1 pins are configured for hi-Z input, L1 is not
using CKX on the USART, and Multi-Input Wake-up for these
pins is disabled.
The device offers system designers a variety of low-power
consumption features that enable them to meet the demand-
ing requirements of today’s increasing range of low-power
applications. These features include low voltage operation,
low current drain, and power saving features such as HALT,
IDLE, and Multi-Input Wake-Up (MIWU).
A diagram of the three modes is shown in Figure 19.
This device supports three operating modes, each of which
have two power save modes of operation. The three operat-
20032722
FIGURE 19. Diagram of Power Save Modes
lator. When HSON = 0, the high speed oscillator
is off. When HSON = 1, the high speed oscillator
is on. There is a startup time associated with this
oscillator. See the startup time table in the Os-
cillator Circuits section.
13.1 POWER SAVE MODE CONTROL REGISTER
The ITMR control register allows for navigation between the
three different modes of operation. It is also used for the Idle
Timer. The register bit assignments are shown below. This
register is cleared to 40 (hex) by Reset as shown below.
DCEN:
This bit selects the clock source for the Idle
Timer. If this bit = 0, then the high speed clock is
the clock source for the Idle Timer. If this bit = 1,
then the low speed clock is the clock source for
the Idle Timer. The low speed oscillator must be
started and stabilized before setting this bit to a
1.
LSON
HSON
DCEN
CCK
SEL
RSVD
ITSEL2 ITSEL1 ITSEL0
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2 Bit 1 Bit 0
LSON:
This bit is used to turn-on the low-speed oscilla-
tor. When LSON = 0, the low speed oscillator is
off. When LSON = 1, the low speed oscillator is
on. There is a startup time associated with this
oscillator. See the Oscillator Circuits section.
CCKSEL: This bit selects whether the high speed clock or
low speed clock is gated to the microcontroller
core. When this bit = 0, the Core clock will be the
HSON:
This bit is used to turn-on the high speed oscil-
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36
13.3.1 High Speed Halt Mode
13.0 Power Saving Features
The fully static architecture of this device allows the state of
the microcontroller to be frozen. This is accomplished by
stopping the internal clock of the device during the HALT
mode. The controller also stops the CKI pin from oscillating
during the HALT mode. The processor can be forced to exit
the HALT mode and resume normal operation at any time.
(Continued)
high speed clock. When this bit = 1, then the
Core clock will be the low speed clock. Before
switching this bit to either state, the appropriate
clock should be turned on and stabilized.
During normal operation, the actual power consumption de-
pends heavily on the clock speed and operating voltage
used in an application and is shown in the Electrical Speci-
fications. In the HALT mode, the device only draws a small
leakage current, plus current for the BOR feature, plus any
current necessary for driving the outputs. Since total power
consumption is affected by the amount of current required to
drive the outputs, all I/Os should be configured to draw
minimal current prior to entering the HALT mode, if possible.
In order to reduce power consumption even further, the
power supply (VCC) can be reduced to a very low level
during the HALT mode, just high enough to guarantee reten-
tion of data stored in RAM. The allowed lower voltage level
(VR) is specified in the Electrical Specs section.
DCEN CCKSEL
0
1
1
0
0
0
1
1
High Speed Mode. Core and Idle Timer
Clock = High Speed
Dual Clock Mode. Core clock = High
Speed; Idle Timer = Low Speed
Low Speed Mode. Core and Idle Timer
Clock = Low Speed
Invalid. If this is detected, the Low
Speed Mode will be forced.
RSVD:
This bit is reserved and must be 0.
Bits 2–0: These are bits used to control the Idle Timer. See
Section 12.1 TIMER T0 (IDLE TIMER) for the
description of these bits.
13.3.1.1 Entering The High Speed Halt Mode
The device enters the HALT mode under software control
when the Port G data register bit 7 is set to 1. All processor
action stops in the middle of the next instruction cycle, and
power consumption is reduced to a very low level.
Table 16 lists the valid contents of the four most significant
bits of the ITMR Register. Any other value is illegal. States
are presented in the only valid sequence. Any other value is
illegal and will result in an unrecoverable loss of a clock to
the CPU core. To prevent this condition, the device will
automatically reset if any illegal value is detected.
13.3.1.2 Exiting The High Speed Halt Mode
There is a choice of methods for exiting the HALT mode: a
chip Reset using the RESET pin or a Multi-Input Wake-up.
TABLE 16. Valid Contents of Dual Clock Control Bits
13.3.1.3 HALT Exit Using Reset
LSON HSON DCEN CCKSEL
Mode
High Speed
A device Reset, which is invoked by a low-level signal on the
RESET input pin, takes the device out of the HALT mode
and starts execution from address 0000H. The initialization
software should determine what special action is needed, if
any, upon start-up of the device from HALT. The initialization
of all registers following a RESET exit from HALT is de-
scribed in the Reset section of this manual.
0
1
1
1
0
0
0
0
High Speed/Dual
Clock Transition
Dual Clock
1
1
1
1
1
1
0
1
Dual Clock/Low
Speed Transition
Low Speed
1
0
1
1
13.3.1.4 HALT Exit Using Multi-Input Wake-up
The device can be brought out of the HALT mode by a
transition received on one of the available Wake-up pins.
The pins used and the types of transitions sensed on the
Multi-input pins are software programmable. For information
on programming and using the Multi-Input Wake-up feature,
refer to the Multi-Input Wake-up section.
13.2 OSCILLATOR STABILIZATION
Both the high speed oscillator and low speed oscillator have
a startup delay associated with them. When switching be-
tween the modes, the software must ensure that the appro-
priate oscillator is started up and stabilized before switching
to the new mode. See Table 3, Startup Times for approxi-
mate startup times for both oscillators.
A start-up delay is required between the device wake-up and
the execution of program instructions, depending on the type
of chip clock. The start-up delay is mandatory, and is imple-
mented whether or not the CLKDLY bit is set. This is be-
cause all crystal oscillators and resonators require some
time to reach a stable frequency and full operating ampli-
tude.
13.3 HIGH SPEED MODE OPERATION
This mode of operation allows high speed operation for both
the main Core clock and also for the Idle Timer. This is the
default mode of the device and will always be entered upon
any of the Reset conditions described in the Reset section. It
can also be entered from Dual Clock mode. It cannot be
directly entered from the Low Speed mode without passing
through the Dual Clock mode first.
The IDLE Timer (Timer T0) provides a fixed delay from the
time the clock is enabled to the time the program execution
begins. Upon exit from the HALT mode, the IDLE Timer is
enabled with a starting value of 256 and is decremented with
each instruction cycle. (The instruction clock runs at one-fifth
the frequency of the high speed oscillator.) An internal
Schmitt trigger connected to the on-chip CKI inverter en-
sures that the IDLE Timer is clocked only when the oscillator
has a large enough amplitude. (The Schmitt trigger is not
part of the oscillator closed loop.) When the IDLE Timer
To enter from the Dual Clock mode, the following sequence
must be followed using two separate instructions:
1. Software clears DCEN to 0.
2. Software clears LSON to 0.
37
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13.3.1.5 Options
13.0 Power Saving Features
This device has two options associated with the HALT mode.
The first option enables the HALT mode feature, while the
second option disables HALT mode operation. Selecting the
disable HALT mode option will cause the microcontroller to
ignore any attempts to HALT the device under software
control. Note that this device can still be placed in the HALT
mode by stopping the clock input to the microcontroller, if the
program memory is masked ROM. See the Option section
for more details on this option bit.
(Continued)
underflows, the clock signals are enabled on the chip, allow-
ing program execution to proceed. Thus, the delay is equal
to 256 instruction cycles.
Note: To ensure accurate operation upon start-up of the
device using Multi-input Wake-up, the instruction in the ap-
plication program used for entering the HALT mode should
be followed by two consecutive NOP (no-operation) instruc-
tions.
20032723
FIGURE 20. Wake-up from HALT
13.3.2 High Speed Idle Mode
input. Upon reset the ITMR register is cleared and the ITMR
register selects the 4,096 instruction cycle tap of the Idle
Timer.
In the IDLE mode, program execution stops and power
consumption is reduced to a very low level as with the HALT
mode. However, the high speed oscillator, IDLE Timer (Timer
T0), and Clock Monitor continue to operate, allowing real
time to be maintained. The device remains idle for a selected
amount of time up to 65,536 instruction cycles, or 32.768
milliseconds with a 2 MHz instruction clock frequency, and
then automatically exits the IDLE mode and returns to nor-
mal program execution.
The IDLE Timer cannot be started or stopped under software
control, and it is not memory mapped, so it cannot be read or
written by the software. Its state upon Reset is unknown.
Therefore, if the device is put into the IDLE mode at an
arbitrary time, it will stay in the IDLE mode for somewhere
between 1 and the selected number of instruction cycles.
In order to precisely time the duration of the IDLE state, entry
into the IDLE mode must be synchronized to the state of the
IDLE Timer. The best way to do this is to use the IDLE Timer
interrupt, which occurs on every underflow of the bit of the
IDLE Timer which is associated with the selected window.
Another method is to poll the state of the IDLE Timer pending
bit T0PND, which is set on the same occurrence. The Idle
Timer interrupt is enabled by setting bit T0EN in the ICNTRL
register.
The device is placed in the IDLE mode under software
control by setting the IDLE bit (bit 6 of the Port G data
register).
The IDLE Timer window is selectable from one of five values,
4k, 8k, 16k, 32k or 64k instruction cycles. Selection of this
value is made through the ITMR register.
The IDLE mode uses the on-chip IDLE Timer (Timer T0) to
keep track of elapsed time in the IDLE state. The IDLE Timer
runs continuously at the instruction clock rate, whether or not
the device is in the IDLE mode. Each time the bit of the timer
associated with the selected window toggles, the T0PND bit
is set, an interrupt is generated (if enabled), and the device
exits the IDLE mode if in that mode. If the IDLE Timer
interrupt is enabled, the interrupt is serviced before execu-
tion of the main program resumes. (However, the instruction
which was started as the part entered the IDLE mode is
completed before the interrupt is serviced. This instruction
should be a NOP which should follow the enter IDLE instruc-
tion.) The user must reset the IDLE Timer pending flag
(T0PND) before entering the IDLE mode.
Any time the IDLE Timer window length is changed there is
the possibility of generating a spurious IDLE Timer interrupt
by setting the T0PND bit. The user is advised to disable
IDLE Timer interrupts prior to changing the value of the
ITSEL bits of the ITMR Register and then clear the TOPND
bit before attempting to synchronize operation to the IDLE
Timer.
Note: As with the HALT mode, it is necessary to program two
NOP’s to allow clock resynchronization upon return from the
IDLE mode. The NOP’s are placed either at the beginning of
the IDLE Timer interrupt routine or immediately following the
“enter IDLE mode” instruction.
As with the HALT mode, this device can also be returned to
normal operation with a reset, or with a Multi-Input Wake-up
For more information on the IDLE Timer and its associated
interrupt, see the description in the Timers section.
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38
Multi-input pins are software programmable. For information
on programming and using the Multi-Input Wake-up feature,
refer to Section 13.6 MULTI-INPUT WAKE-UP.
13.0 Power Saving Features
(Continued)
13.4 DUAL CLOCK MODE OPERATION
A start-up delay is required between the device wake-up and
the execution of program instructions. The start-up delay is
mandatory, and is implemented whether or not the CLKDLY
bit is set. This is because all crystal oscillators and resona-
tors require some time to reach a stable frequency and full
operating amplitude.
This mode of operation allows for high speed operation of
the Core clock and low speed operation of the Idle Timer.
This mode can be entered from either the High Speed mode
or the Low Speed mode.
To enter from the High Speed mode, the following sequence
must be followed:
If the start-up delay is used, the IDLE Timer (Timer T0)
provides a fixed delay from the time the clock is enabled to
the time the program execution begins. Upon exit from the
HALT mode, the IDLE Timer is enabled with a starting value
of 256 and is decremented with each instruction cycle using
the high speed clock. (The instruction clock runs at one-fifth
the frequency of the high speed oscillatory.) An internal
Schmitt trigger connected to the on-chip CKI inverter en-
sures that the IDLE Timer is clocked only when the high
speed oscillator has a large enough amplitude. (The Schmitt
trigger is not part of the oscillator closed loop.) When the
IDLE Timer underflows, the clock signals are enabled on the
chip, allowing program execution to proceed. Thus, the delay
is equal to 256 instruction cycles. After exiting HALT, the Idle
Timer will return to being clocked by the low speed clock.
1. Software sets the LSON bit to 1.
2. Software waits until the low speed oscillator has stabi-
lized. See Table 3.
3. Software sets the DCEN bit to 1.
To enter from the Low Speed mode, the following sequence
must be followed:
1. Software sets the HSON bit to 1.
2. Software waits until the high speed oscillator has stabi-
lized. See Table 3, Startup Times.
3. Software clears the CCKSEL bit to 0.
13.4.1 Dual Clock HALT Mode
The fully static architecture of this device allows the state of
the microcontroller to be frozen. This is accomplished by
stopping the high speed clock of the device during the HALT
mode. The processor can be forced to exit the HALT mode
and resume normal operation at any time. The low speed
clock remains on during HALT in the Dual Clock mode.
Note: To ensure accurate operation upon start-up of the
device using Multi-input Wake-up, the instruction in the ap-
plication program used for entering the HALT mode should
be followed by two consecutive NOP (no-operation) instruc-
tions.
13.4.1.5 Options
During normal operation, the actual power consumption de-
pends heavily on the clock speed and operating voltage
used in an application and is shown in the Electrical Speci-
fications. In the HALT mode, the device only draws a small
leakage current, plus current for the BOR feature, plus the
32 kHz oscillator current, plus any current necessary for
driving the outputs. Since total power consumption is af-
fected by the amount of current required to drive the outputs,
all I/Os should be configured to draw minimal current prior to
entering the HALT mode, if possible.
This device has two options associated with the HALT mode.
The first option enables the HALT mode feature, while the
second option disables HALT mode operation. Selecting the
disable HALT mode option will cause the microcontroller to
ignore any attempts to HALT the device under software
control. See Section 10.5 OPTION REGISTER for more
details on this option bit.
13.4.2 Dual Clock Idle Mode
In the IDLE mode, program execution stops and power
consumption is reduced to a very low level as with the HALT
mode. However, both oscillators, IDLE Timer (Timer T0), and
Clock Monitor continue to operate, allowing real time to be
maintained. The Idle Timer is clocked by the low speed
clock. The device remains idle for a selected amount of time
up to 2 seconds, and then automatically exits the IDLE mode
and returns to normal program execution using the high
speed clock.
13.4.1.1 Entering The Dual Clock Halt Mode
The device enters the HALT mode under software control
when the Port G data register bit 7 is set to 1. All processor
action stops in the middle of the next instruction cycle, and
power consumption is reduced to a very low level. In order to
expedite exit from HALT, the low speed oscillator is left
running when the device is Halted in the Dual Clock mode.
However, the Idle Timer will not be clocked.
The device is placed in the IDLE mode under software
control by setting the IDLE bit (bit 6 of the Port G data
register).
13.4.1.2 Exiting The Dual Clock Halt Mode
When the HALT mode is entered by setting bit 7 of the Port
G data register, there is a choice of methods for exiting the
HALT mode: a chip Reset using the RESET pin or a Multi-
Input Wake-up. The Reset method and Multi-Input Wake-up
method can be used with any clock option.
The IDLE Timer window is selectable from one of five values,
0.125 seconds, 0.25 seconds, 0.5 seconds, 1 second and
2 seconds. Selection of this value is made through the ITMR
register.
The IDLE mode uses the on-chip IDLE Timer (Timer T0) to
keep track of elapsed time in the IDLE state. The IDLE Timer
runs continuously at the low speed clock rate, whether or not
the device is in the IDLE mode. Each time the bit of the timer
associated with the selected window toggles, the T0PND bit
is set, an interrupt is generated (if enabled), and the device
exits the IDLE mode if in that mode. If the IDLE Timer
interrupt is enabled, the interrupt is serviced before execu-
tion of the main program resumes. (However, the instruction
13.4.1.3 HALT Exit Using Reset
A device Reset, which is invoked by a low-level signal on the
RESET input pin, takes the device out of the Dual Clock
mode and puts it into the High Speed mode.
13.4.1.4 HALT Exit Using Multi-Input Wake-up
The device can be brought out of the HALT mode by a
transition received on one of the available Wake-up pins.
The pins used and the types of transitions sensed on the
39
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During normal operation, the actual power consumption de-
pends heavily on the clock speed and operating voltage
used in an application and is shown in the Electrical Speci-
fications. In the HALT mode, the device only draws a small
leakage current, plus current for the BOR feature, plus the
32 kHz oscillator current, plus any current necessary for
driving the outputs. Since total power consumption is af-
fected by the amount of current required to drive the outputs,
all I/Os should be configured to draw minimal current prior to
entering the HALT mode, if possible.
13.0 Power Saving Features
(Continued)
which was started as the part entered the IDLE mode is
completed before the interrupt is serviced. This instruction
should be a NOP which should follow the enter IDLE instruc-
tion.) The user must reset the IDLE Timer pending flag
(T0PND) before entering the IDLE mode.
As with the HALT mode, this device can also be returned to
normal operation with a Multi-Input Wake-up input.
The IDLE Timer cannot be started or stopped under software
control, and it is not memory mapped, so it cannot be read or
written by the software. Its state upon Reset is unknown.
Therefore, if the device is put into the IDLE mode at an
arbitrary time, it will stay in the IDLE mode for somewhere
between 30 µs and the selected time period.
13.5.1.1 Entering The Low Speed Halt Mode
The device enters the HALT mode under software control
when the Port G data register bit 7 is set to 1. All processor
action stops in the middle of the next instruction cycle, and
power consumption is reduced to a very low level. In order to
expedite exit from HALT, the low speed oscillator is left
running when the device is Halted in the Low Speed mode.
However, the Idle Timer will not be clocked.
In order to precisely time the duration of the IDLE state, entry
into the IDLE mode must be ”synchronized to the state of the
IDLE Timer. The best way to do this is to use the IDLE Timer
interrupt, which occurs on every underflow of the bit of the
IDLE Timer which is associated with the selected window.
Another method is to poll the state of the IDLE Timer pending
bit T0PND, which is set on the same occurrence. The Idle
Timer interrupt is enabled by setting bit T0EN in the ICNTRL
register.
13.5.1.2 Exiting The Low Speed Halt Mode
When the HALT mode is entered by setting bit 7 of the Port
G data register, there is a choice of methods for exiting the
HALT mode: a chip Reset using the RESET pin or a Multi-
Input Wake-up. The Reset method and Multi-Input Wake-up
method can be used with any clock option, but the availabil-
ity of the G7 input is dependent on the clock option.
Any time the IDLE Timer window length is changed there is
the possibility of generating a spurious IDLE Timer interrupt
by setting the T0PND bit. The user is advised to disable
IDLE Timer interrupts prior to changing the value of the
ITSEL bits of the ITMR Register and then clear the T0PND
bit before attempting to synchronize operation to the IDLE
Timer.
13.5.1.3 HALT Exit Using Reset
A device Reset, which is invoked by a low-level signal on the
RESET input pin, takes the device out of the Low Speed
mode and puts it into the High Speed mode.
Note: As with the HALT mode, it is necessary to program two
NOP’s to allow clock resynchronization upon return from the
IDLE mode. The NOP’s are placed either at the beginning of
the IDLE Timer interrupt routine or immediately following the
“enter IDLE mode” instruction.
13.5.1.4 HALT Exit Using Multi-Input Wake-up
The device can be brought out of the HALT mode by a
transition received on one of the available Wake-up pins.
The pins used and the types of transitions sensed on the
Multi-input pins are software programmable. For information
on programming and using the Multi-Input Wake-up feature,
refer to the Multi-Input Wake-up section.
For more information on the IDLE Timer and its associated
interrupt, see the description in the Timers section.
As the low speed oscillator is left running, there is no start up
delay when exiting the low speed halt mode, regardless of
the state of the CLKDLY bit.
13.5 LOW SPEED MODE OPERATION
This mode of operation allows for low speed operation of the
core clock and low speed operation of the Idle Timer. Be-
cause the low speed oscillator draws very little operating
current, and also to expedite restarting from HALT mode, the
low speed oscillator is left on at all times in this mode,
including HALT mode. This is the lowest power mode of
operation on the device. This mode can only be entered from
the Dual Clock mode.
Note: To ensure accurate operation upon start-up of the
device using Multi-input Wake-up, the instruction in the ap-
plication program used for entering the HALT mode should
be followed by two consecutive NOP (no-operation) instruc-
tions.
13.5.1.5 Options
To enter the Low Speed mode, the following sequence must
be followed using two separate instructions:
This device has two options associated with the HALT mode.
The first option enables the HALT mode feature, while the
second option disables HALT mode operation. Selecting the
disable HALT mode option will cause the microcontroller to
ignore any attempts to HALT the device under software
control. See the Option section for more details on this
option bit.
1. Software sets the CCKSEL bit to 1.
2. Software clears the HSON bit to 0.
Since the low speed oscillator is already running, there is no
clock startup delay.
13.5.1 Low Speed HALT Mode
13.5.2 Low Speed Idle Mode
The fully static architecture of this device allows the state of
the microcontroller to be frozen. Because the low speed
oscillator draws very minimal operating current, it will be left
running in the low speed halt mode. However, the Idle Timer
will not be running. This also allows for a faster exit from
HALT. The processor can be forced to exit the HALT mode
and resume normal operation at any time.
In the IDLE mode, program execution stops and power
consumption is reduced to a very low level as with the HALT
mode. However, the low speed oscillator, IDLE Timer (Timer
T0), and Clock Monitor continue to operate, allowing real
time to be maintained. The device remains idle for a selected
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40
written by the software. Its state upon Reset is unknown.
Therefore, if the device is put into the IDLE mode at an
arbitrary time, it will stay in the IDLE mode for somewhere
between 30 µs and the selected time period.
13.0 Power Saving Features
(Continued)
amount of time up to 2 seconds, and then automatically exits
the IDLE mode and returns to normal program execution
using the low speed clock.
In order to precisely time the duration of the IDLE state, entry
into the IDLE mode must be synchronized to the state of the
IDLE Timer. The best way to do this is to use the IDLE Timer
interrupt, which occurs on every underflow of the bit of the
IDLE Timer which is associated with the selected window.
Another method is to poll the state of the IDLE Timer pending
bit T0PND, which is set on the same occurrence. The Idle
Timer interrupt is enabled by setting bit T0EN in the ICNTRL
register.
The device is placed in the IDLE mode under software
control by setting the IDLE bit (bit 6 of the Port G data
register).
The IDLE Timer window is selectable from one of five values,
0.125 seconds, 0.25 seconds, 0.5 seconds, 1 second, and
2 seconds. Selection of this value is made through the ITMR
register.
Any time the IDLE Timer window length is changed there is
the possibility of generating a spurious IDLE Timer interrupt
by setting the T0PND bit. The user is advised to disable
IDLE Timer interrupts prior to changing the value of the
ITSEL bits of the ITMR Register and then clear the T0PND
bit before attempting to synchronize operation to the IDLE
Timer.
The IDLE mode uses the on-chip IDLE Timer (Timer T0) to
keep track of elapsed time in the IDLE state. The IDLE Timer
runs continuously at the low speed clock rate, whether or not
the device is in the IDLE mode. Each time the bit of the timer
associated with the selected window toggles, the T0PND bit
is set, an interrupt is generated (if enabled), and the device
exits the IDLE mode if in that mode. If the IDLE Timer
interrupt is enabled, the interrupt is serviced before execu-
tion of the main program resumes. (However, the instruction
which was started as the part entered the IDLE mode is
completed before the interrupt is serviced. This instruction
should be a NOP which should follow the enter IDLE instruc-
tion.) The user must reset the IDLE Timer pending flag
(T0PND) before entering the IDLE mode.
As with the HALT mode, it is necessary to program two
NOP’s to allow clock resynchronization upon return from the
IDLE mode. The NOP’s are placed either at the beginning of
the IDLE Timer interrupt routine or immediately following the
“enter IDLE mode” instruction.
For more information on the IDLE Timer and its associated
interrupt, see the description in the Section 6.1, Timer T0
(IDLE Timer).
As with the HALT mode, this device can also be returned to
normal operation with a Multi-Input Wake-up input.
The IDLE Timer cannot be started or stopped under software
control, and it is not memory mapped, so it cannot be read or
20032724
FIGURE 21. Multi-Input Wake-Up Logic
41
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be set or reset for the desired edge selects, followed by the
associated WKPND bits being cleared.
13.0 Power Saving Features
(Continued)
This same procedure should be used following reset, since
the L port inputs are left floating as a result of reset.
13.6 MULTI-INPUT WAKE-UP
The Multi-Input Wake-up feature is used to return (wake-up)
the device from either the HALT or IDLE modes. Alternately
Multi-Input Wake-up/Interrupt feature may also be used to
generate up to 8 edge selectable external interrupts.
The occurrence of the selected trigger condition for Multi-
Input Wake-up is latched into a pending register called
WKPND. The respective bits of the WKPND register will be
set on the occurrence of the selected trigger edge on the
corresponding Port L pin. The user has the responsibility of
clearing these pending flags. Since WKPND is a pending
register for the occurrence of selected wake-up conditions,
the device will not enter the HALT mode if any Wake-up bit is
both enabled and pending. Consequently, the user must
clear the pending flags before attempting to enter the HALT
mode.
Figure 21 shows the Multi-Input Wake-up logic.
The Multi-Input Wake-up feature utilizes the L Port. The user
selects which particular L port bit (or combination of L Port
bits) will cause the device to exit the HALT or IDLE modes.
The selection is done through the register WKEN. The reg-
ister WKEN is an 8-bit read/write register, which contains a
control bit for every L port bit. Setting a particular WKEN bit
enables a Wake-up from the associated L port pin.
WKEN and WKEDG are all read/write registers, and are
cleared at reset. WKPND register contains random value
after reset.
The user can select whether the trigger condition on the
selected L Port pin is going to be either a positive edge (low
to high transition) or a negative edge (high to low transition).
This selection is made via the register WKEDG, which is an
8-bit control register with a bit assigned to each L Port pin.
Setting the control bit will select the trigger condition to be a
negative edge on that particular L Port pin. Resetting the bit
selects the trigger condition to be a positive edge. Changing
an edge select entails several steps in order to avoid a
Wake-up condition as a result of the edge change. First, the
associated WKEN bit should be reset, followed by the edge
select change in WKEDG. Next, the associated WKPND bit
should be cleared, followed by the associated WKEN bit
being re-enabled.
14.0 USART
The device contains a full-duplex software programmable
USART. The USART (Figure 22) consists of a transmit shift
register, a receive shift register and seven addressable reg-
isters, as follows: a transmit buffer register (TBUF), a re-
ceiver buffer register (RBUF), a USART control and status
register (ENU), a USART receive control and status register
(ENUR), a USART interrupt and clock source register
(ENUI), a prescaler select register (PSR) and baud (BAUD)
register. The ENU register contains flags for transmit and
receive functions; this register also determines the length of
the data frame (7, 8 or 9 bits), the value of the ninth bit in
transmission, and parity selection bits. The ENUR register
flags framing, data overrun, parity errors and line breaks
while the USART is receiving.
An example may serve to clarify this procedure. Suppose we
wish to change the edge select from positive (low going high)
to negative (high going low) for L Port bit 5, where bit 5 has
previously been enabled for an input interrupt. The program
would be as follows:
Other functions of the ENUR register include saving the
ninth bit received in the data frame, enabling or disabling the
USART’s attention mode of operation and providing addi-
tional receiver/transmitter status information via RCVG and
XMTG bits. The determination of an internal or external clock
source is done by the ENUI register, as well as selecting the
number of stop bits and enabling or disabling transmit and
receive interrupts. A control flag in this register can also
select the USART mode of operation: asynchronous or
synchronous.
RBIT 5, WKEN
; Disable MIWU
SBIT 5, WKEDG ; Change edge polarity
RBIT 5, WKPND ; Reset pending flag
SBIT 5, WKEN
; Enable MIWU
If the L port bits have been used as outputs and then
changed to inputs with Multi-Input Wake-up/Interrupt, a
safety procedure should also be followed to avoid wake-up
conditions. After the selected L port bits have been changed
from output to input but before the associated WKEN bits are
enabled, the associated edge select bits in WKEDG should
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14.0 USART (Continued)
20032725
FIGURE 22. USART Block Diagram
14.1 USART CONTROL AND STATUS REGISTERS
PEN: This bit enables/disables Parity (7- and 8-bit modes
only). Read/Write, cleared on reset.
The operation of the USART is programmed through three
registers: ENU, ENUR and ENUI.
PEN = 0
PEN = 1
Parity disabled.
Parity enabled.
14.2 DESCRIPTION OF USART REGISTER BITS
PSEL1, PSEL0: Parity select bits. Read/Write, cleared on
reset.
ENU—USART CONTROL AND STATUS REGISTER (Ad-
dress at 0BA)
PSEL1 = 0, PSEL0 = 0
PSEL1 = 0, PSEL1 = 1
PSEL1 = 1, PSEL0 = 0
PSEL1 = 1, PSEL1 = 1
Odd Parity (if Parity enabled)
Even Parity (if Parity enabled)
Mark(1) (if Parity enabled)
Space(0) (if Parity enabled)
PEN PSEL1 XBIT9/ CHL1 CHL0 ERR RBFL TBMT
PSEL0
Bit 7
Bit 0
43
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XMTG: This bit is set to indicate that the USART is transmit-
ting. It gets reset at the end of the last frame (end of last Stop
bit). Read only, cleared on reset.
14.0 USART (Continued)
XBIT9/PSEL0: Programs the ninth bit for transmission when
the USART is operating with nine data bits per frame. For
seven or eight data bits per frame, this bit in conjunction with
PSEL1 selects parity. Read/Write, cleared on reset.
RCVG: This bit is set high whenever a framing error or a
break detect occurs and goes low when RDX goes high.
Read only, cleared on reset.
CHL1, CHL0: These bits select the character frame format.
Parity is not included and is generated/verified by hardware.
Read/Write, cleared on reset.
ENUI—USART INTERRUPT AND CLOCK SOURCE REG-
ISTER (Address at 0BC)
STP2 BRK
Bit 7
ETDX SSEL XRCLK XTCLK ERI
ETI
CHL1 = 0, CHL0 = 0
CHL1 = 0, CHL0 = 1
CHL1 = 1, CHL0 = 0
CHL1 = 1, CHL0 = 1
The frame contains eight data bits.
The frame contains seven data bits.
The frame contains nine data bits.
Bit 0
STP2: This bit programs the number of Stop bits to be
transmitted. Read/Write, cleared on reset.
Loopback Mode selected. Trans-
mitter output internally looped back
to receiver input. Nine bit framing
format is used.
STP2 = 0
STP2 = 1
One Stop bit transmitted.
Two Stop bits transmitted.
BRK: Holds TDX (USART Transmit Pin) low to generate a
Line Break. Timing of the Line Break is under software
control.
ERR: This bit is a global USART error flag which gets set if
any or a combination of the errors (DOE, FE, PE, BD) occur.
Read only; it cannot be written by software, cleared on reset.
ETDX: TDX (USART Transmit Pin) is the alternate function
assigned to Port L pin L2; it is selected by setting ETDX bit.
RBFL: This bit is set when the USART has received a
complete character and has copied it into the RBUF register.
It is automatically reset when software reads the character
from RBUF. Read only; it cannot be written by software,
cleared on reset.
SSEL: USART mode select. Read only, cleared on reset.
SSEL = 0
SSEL = 1
Asynchronous Mode.
Synchronous Mode.
TBMT: This bit is set when the USART transfers a byte of
data from the TBUF register into the TSFT register for trans-
mission. It is automatically reset when software writes into
the TBUF register. Read only, bit is set to “one” on reset; it
cannot be written by software.
XRCLK: This bit selects the clock source for the receiver
section. Read/Write, cleared on reset.
XRCLK = 0
The clock source is selected through the
PSR and BAUD registers.
XRCLK = 1
Signal on CKX (L1) pin is used as the clock.
ENUR—USART RECEIVE CONTROL AND STATUS REG-
ISTER (Address at 0BB)
XTCLK: This bit selects the clock source for the transmitter
section. Read/Write, cleared on reset.
DOE
Bit 7
FE
PE
BD
RBIT9 ATTN XMTG RCVG
Bit 0
XTCLK = 0
The clock source is selected through the PSR
and BAUD registers.
XTCLK = 1
Signal on CKX (L1) pin is used as the clock.
DOE: Flags a Data Overrun Error. Read only, cleared on
read, cleared on reset.
ERI: This bit enables/disables interrupt from the receiver
section. Read/Write, cleared on reset.
DOE = 0
Indicates no Data Overrun Error has been de-
tected since the last time the ENUR register
was read.
ERI = 0
ERI = 1
Interrupt from the receiver is disabled.
Interrupt from the receiver is enabled.
ETI: This bit enables/disables interrupt from the transmitter
section. Read/Write, cleared on reset.
DOE = 1
Indicates the occurrence of a Data Overrun
Error.
ETI = 0
ETI = 1
Interrupt from the transmitter is disabled.
Interrupt from the transmitter is enabled.
FE: Flags a Framing Error. Read only, cleared on read,
cleared on reset.
FE = 0
Indicates no Framing Error has been detected
since the last time the ENUR register was read.
14.3 ASSOCIATED I/O PINS
Data is transmitted on the TDX pin and received on the RDX
pin. TDX is the alternate function assigned to Port L pin L2;
it is selected by setting ETDX (in the ENUI register) to one.
RDX is an inherent function Port L pin L3, requiring no setup.
Port L pin L2 must be configured as an output in the Port L
Configuration Register in order to be used as the TDX pin.
FE = 1
Indicates the occurrence of a Framing Error.
PE: Flags a Parity Error. Read only, cleared on read, cleared
on reset.
PE = 0
Indicates no Parity Error has been detected since
the last time the ENUR register was read.
PE = 1
Indicates the occurrence of a Parity Error.
The baud rate clock for the USART can be generated on-
chip, or can be taken from an external source. Port L pin L1
(CKX) is the external clock I/O pin. The CKX pin can be
either an input or an output, as determined by Port L Con-
figuration and Data registers (Bit 1). As an input, it accepts a
clock signal which may be selected to drive the transmitter
and/or receiver. As an output, it presents the internal Baud
Rate Generator output.
BD: Flags a line break.
BD = 0 Indicates no Line Break has been detected since
the last time the ENUR register was read.
BD = 1 Indicates the occurrence of a Line Break.
RBIT9: Contains the ninth data bit received when the
USART is operating with nine data bits per frame. Read only,
cleared on reset.
Note: The CKX pin is unavailable if Port L1 is used for the
Low Speed Oscillator.
ATTN: ATTENTION Mode is enabled while this bit is set.
This bit is cleared automatically on receiving a character with
data bit nine set. Read/Write, cleared on reset.
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LD A, RBUF ;Clear RBFL
14.0 USART (Continued)
14.4 USART OPERATION
RBIT SSEL,ENUI ;Back to asynch mode
LD PSR,#000 ;Stop USART clock before
;restarting
LD ENU, #000 ; Replace with normal ENU value
LD PSR,#0C9 ;Restore the PSR to restart
;the USART
The USART has two modes of operation: asynchronous
mode and synchronous mode.
14.4.1 Asynchronous Mode
RET
This mode is selected by resetting the SSEL (in the ENUI
register) bit to zero. The input frequency to the USART is
16 times the baud rate.
The same subroutine works for a break detect, but you need
to be careful. If the break is still in force when the PSR is
restored, another break detect will occur. The part could
easily end up spending all of it’s cycles just handling break
detects. The user may wish to delay handling break detects
until RDX goes high (poll the pin periodically, or use MIWU).
The TSFT and TBUF registers double-buffer data for trans-
mission. While TSFT is shifting out the current character on
the TDX pin, the TBUF register may be loaded by software
with the next byte to be transmitted. When TSFT finishes
transmitting the current character the contents of TBUF are
transferred to the TSFT register and the Transmit Buffer
Empty Flag (TBMT in the ENU register) is set. The TBMT
flag is automatically reset by the USART when software
loads a new character into the TBUF register. There is also
the XMTG bit which is set to indicate that the USART is
transmitting. This bit gets reset at the end of the last frame
(end of last Stop bit). TBUF is a read/write register.
14.4.2 Synchronous Mode
In this mode data is transferred synchronously with the
clock. Data is transmitted on the rising edge and received on
the falling edge of the synchronous clock.
This mode is selected by setting SSEL bit in the ENUI
register. The input frequency to the USART is the same as
the baud rate.
The RSFT and RBUF registers double-buffer data being
received. The USART receiver continually monitors the sig-
nal on the RDX pin for a low level to detect the beginning of
a Start bit. Upon sensing this low level, it waits for half a bit
time and samples again. If the RDX pin is still low, the
receiver considers this to be a valid Start bit, and the remain-
ing bits in the character frame are each sampled three times
around the center of the bit time. Serial data input on the
RDX pin is shifted into the RSFT register. Upon receiving the
complete character, the contents of the RSFT register are
copied into the RBUF register and the Received Buffer Full
Flag (RBFL) is set. RBFL is automatically reset when soft-
ware reads the character from the RBUF register. RBUF is a
read only register. There is also the RCVG bit which is set
high when a framing error or a break detect occurs and goes
low once RDX goes high.
When an external clock input is selected at the CKX pin, data
transmit and receive are performed synchronously with this
clock through TDX/RDX pins.
If data transmit and receive are selected with the CKX pin as
clock output, the device generates the synchronous clock
output at the CKX pin. The internal baud rate generator is
used to produce the synchronous clock. Data transmit and
receive are performed synchronously with this clock.
14.5 FRAMING FORMATS
The USART supports several serial framing formats (Figure
23). The format is selected using control bits in the ENU,
ENUR and ENUI registers.
The first format (1, 1a, 1b, 1c) for data transmission (CHL0 =
1, CHL1 = 0) consists of Start bit, seven Data bits (excluding
parity) and one or two Stop bits. In applications using parity,
the parity bit is generated and verified by hardware.
The USART receive state machine can hang after receiving
a frame error or detecting a Line Break condition. The lockup
can be cleared by setting the USART in internal loopback
mode and switching to synchronous operation for a short
time. For faster baud rates, there is no need for a timing loop.
The code that is included works for 300 baud with the device
running on a 10MHz crystal. (2MHz instruction clock, instruc-
The second format (CHL0 = 0, CHL1 = 0) consists of one
Start bit, eight Data bits (excluding parity) and one or two
Stop bits. Parity bit is generated and verified by hardware.
The third format for transmission (CHL0 = 0, CHL1 = 1)
consists of one Start bit, nine Data bits and one or two Stop
bits. This format also supports the USART “ATTENTION”
feature. When operating in this format, all eight bits of TBUF
and RBUF are used for data. The ninth data bit is transmitted
and received using two bits in the ENU and ENUR registers,
called XBIT9 and RBIT9. RBIT9 is a read only bit. Parity is
not generated or verified in this mode.
>
tion cycles for 1/16 bit time delay). At baud rates = 9600
>
baud ( = 4800 baud with a 5MHz xtal) no timing loop is
required. In the following example the UART was initialized
as follows:
PSR = C9
BAUD = 40
The parity is enabled/disabled by PEN bit located in the ENU
register. Parity is selected for 7- and 8-bit modes only. If
parity is enabled (PEN = 1), the parity selection is then
performed by PSEL0 and PSEL1 bits located in the ENU
register.
ENU = 01 ; 8 bits, no parity
;Remember that at the end of the code,
;the PSR and ENU must be restored to
;whatever setting the application requires.
CLERR:
LD ENU, #018 ; Temporarily go into
;loop back mode
SBIT SSEL,ENUI ; Then into synchronous mode
LD 0F1,#69 ;Delay loop timing -
;(6*69-2)/2 = 206uS
LOOP3: ;Bit time/16=208.33uS
DRSZ 0F1 ;Following instructions make up
;the difference
Note that the XBIT9/PSEL0 bit located in the ENU register
serves two mutually exclusive functions. This bit programs
the ninth bit for transmission when the USART is operating
with nine data bits per frame. There is no parity selection in
this framing format. For other framing formats XBIT9 is not
needed and the bit is PSEL0 used in conjunction with PSEL1
to select parity.
The frame formats for the receiver differ from the transmitter
in the number of Stop bits required. The receiver only re-
quires one Stop bit in a frame, regardless of the setting of the
JP LOOP3
LD A, ENUR ;Clear the error flags
45
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implicit assumption is made for full duplex USART operation
that the framing formats are the same for the transmitter and
receiver.
14.0 USART (Continued)
Stop bit selection bits in the control register. Note that an
20032726
FIGURE 23. Framing Formats
14.6 USART INTERRUPTS
remove this interrupt, software must either clear the ERI bit
or read from the RBUF register (thus clearing the RBFL bit).
The USART is capable of generating interrupts. Interrupts
are generated on Receive Buffer Full and Transmit Buffer
Empty. Both interrupts have individual interrupt vectors. Two
bytes of program memory space are reserved for each in-
terrupt vector. The two vectors are located at addresses
0xEC to 0xEF Hex in the program memory space. The
interrupts can be individually enabled or disabled using En-
able Transmit Interrupt (ETI) and Enable Receive Interrupt
(ERI) bits in the ENUI register.
14.7 BAUD CLOCK GENERATION
The clock inputs to the transmitter and receiver sections of
the USART can be individually selected to come either from
an external source at the CKX pin (port L, pin L1) or from a
source selected in the PSR and BAUD registers. Internally,
the basic baud clock is created from the MCLK through a
two-stage divider chain consisting of a 1-16 (increments of
0.5) prescaler and an 11-bit binary counter (Figure 24). The
divide factors are specified through two read/write registers
shown in Figure 25. Note that the 11-bit Baud Rate Divisor
spills over into the Prescaler Select Register (PSR). PSR is
cleared upon reset.
The interrupt from the Transmitter is set pending, and re-
mains pending, as long as both the TBMT and ETI bits are
set. To remove this interrupt, software must either clear the
ETI bit or write to the TBUF register (thus clearing the TBMT
bit).
As shown in Table 18, a Prescaler Factor of 0 corresponds to
NO CLOCK. This condition is the USART power down mode
The interrupt from the receiver is set pending, and remains
pending, as long as both the RBFL and ERI bits are set. To
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14.0 USART (Continued)
where the USART clock is turned off for power saving pur-
pose. The user must also turn the USART clock off when a
different baud rate is chosen.
Prescaler
Select
00100
00101
00110
00111
01000
01001
01010
01011
01100
01101
01110
01111
10000
10001
10010
10011
10100
10101
10110
10111
11000
11001
11010
11011
11100
11101
11110
11111
Prescaler
Factor
2.5
3
The correspondences between the 5-bit Prescaler Select
and Prescaler factors are shown in Table 18. There are
many ways to calculate the two divisor factors, but one
particularly effective method would be to achieve a 1.8432
MHz frequency coming out of the first stage. The 1.8432
MHz prescaler output is then used to drive the software
programmable baud rate counter to create a 16x clock for
the following baud rates: 110, 134.5, 150, 300, 600, 1200,
1800, 2400, 3600, 4800, 7200, 9600, 19200 and 38400
(Table 17). Other baud rates may be created by using ap-
propriate divisors. The 16x clock is then divided by 16 to
provide the rate for the serial shift registers of the transmitter
and receiver.
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
8.5
9
TABLE 17. Baud Rate Divisors
(1.8432 MHz Prescaler Output)
9.5
10
Baud Rate
Baud Rate
Divisor − 1 (N-1)
10.5
11
110 (110.03)
134.5 (134.58)
150
1046
855
767
383
191
95
11.5
12
300
12.5
13
600
1200
13.5
14
1800
63
2400
47
14.5
15
3600
31
4800
23
15.5
16
7200
15
9600
11
As an example, considering Asynchronous Mode and a crys-
tal frequency of 4.608 MHz, the prescaler factor selected is:
19200
38400
5
2
(4.608 x 2)/1.8432 = 5
The 5 entry is available in Table 18. The 1.8432 MHz pres-
caler output is then used with proper Baud Rate Divisor
(Table 17) to obtain different baud rates. For a baud rate of
19200 e.g., the entry in Table 17 is 5.
Note: The entries in Table 17 assume a prescaler output of 1.8432 MHz. In
asynchronous mode the baud rate could be as high as 1250k.
N − 1 = 5 (N − 1 is the value from Table 17)
N = 6 (N is the Baud Rate Divisor)
Baud Rate = 1.8432 MHz/(16 x 6) = 19200
The divide by 16 is performed because in the asynchronous
mode, the input frequency to the USART is 16 times the
baud rate. The equation to calculate baud rates is given
below.
20032727
FIGURE 24. USART BAUD Clock Generation
The actual Baud Rate may be found from:
BR = (FC x 2)/(16 x N x P)
Where:
TABLE 18. Prescaler Factors
Prescaler
Select
00000
Prescaler
BR is the Baud Rate
Factor
FC is the crystal frequency
N is the Baud Rate Divisor (Table 17)
NO CLOCK
P is the Prescaler Divide Factor selected by the value in the
Prescaler Select Register (Table 18)
00001
1
1.5
2
00010
Note: In the Synchronous Mode, the divisor 16 is replaced
by two.
00011
47
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Now 32.552 is divided by each Prescaler Factor (Table 18) to
obtain a value closest to an integer. This factor happens to
be 6.5 (P = 6.5).
14.0 USART (Continued)
Example:
Asynchronous Mode:
N = 32.552/6.5 = 5.008 (N = 5)
Crystal Frequency = 5 MHz
The programmed value (from Table 17) should be 4 (N - 1).
Using the above values calculated for N and P:
BR = (5 x 106 x 2)/(16 x 5 x 6.5) = 19230.769
error = (19230.769 - 19200) x 100/19200 = 0.16%
Desired baud rate = 19200
Using the above equation N x P can be calculated first.
N x P = (5 x 106 x 2)/(16 x 19200) = 32.552
20032728
FIGURE 25. USART BAUD Clock Divisor Registers
14.8 EFFECT OF HALT/IDLE
14.10 ATTENTION MODE
The USART logic is reinitialized when either the HALT or
IDLE modes are entered. This reinitialization sets the TBMT
flag and resets all read only bits in the USART control and
status registers. Read/Write bits remain unchanged. The
Transmit Buffer (TBUF) is not affected, but the Transmit Shift
register (TSFT) bits are set to one. The receiver registers
RBUF and RSFT are not affected.
The USART Receiver section supports an alternate mode of
operation, referred to as ATTENTION Mode. This mode of
operation is selected by the ATTN bit in the ENUR register.
The data format for transmission must also be selected as
having nine Data bits and either one or two Stop bits.
The ATTENTION mode of operation is intended for use in
networking the device with other processors. Typically in
such environments the messages consists of device ad-
dresses, indicating which of several destinations should re-
ceive them, and the actual data. This Mode supports a
scheme in which addresses are flagged by having the ninth
bit of the data field set to a 1. If the ninth bit is reset to a zero
the byte is a Data byte.
The device will exit from the HALT/IDLE modes when the
Start bit of a character is detected at the RDX (L3) pin. This
feature is obtained by using the Multi-Input Wake-up scheme
provided on the device.
Before entering the HALT or IDLE modes the user program
must select the Wake-up source to be on the RDX pin. This
selection is done by setting bit 3 of WKEN (Wake-up Enable)
register. The Wake-up trigger condition is then selected to be
high to low transition. This is done via the WKEDG register
(Bit 3 is one).
While in ATTENTION mode, the USART monitors the com-
munication flow, but ignores all characters until an address
character is received. Upon receiving an address character,
the USART signals that the character is ready by setting the
RBFL flag, which in turn interrupts the processor if USART
Receiver interrupts are enabled. The ATTN bit is also cleared
automatically at this point, so that data characters as well as
address characters are recognized. Software examines the
contents of the RBUF and responds by deciding either to
accept the subsequent data stream (by leaving the ATTN bit
reset) or to wait until the next address character is seen (by
setting the ATTN bit again).
If the device is halted and crystal oscillator is used, the
Wake-up signal will not start the chip running immediately
because of the finite start up time requirement of the crystal
oscillator. The idle timer (T0) generates a fixed (256 tC) delay
to ensure that the oscillator has indeed stabilized before
allowing the device to execute code. The user has to con-
sider this delay when data transfer is expected immediately
after exiting the HALT mode.
Operation of the USART Transmitter is not affected by se-
lection of this Mode. The value of the ninth bit to be trans-
mitted is programmed by setting XBIT9 appropriately. The
value of the ninth bit received is obtained by reading RBIT9.
Since this bit is located in ENUR register where the error
flags reside, a bit operation on it will reset the error flags.
14.9 DIAGNOSTIC
Bits CHL0 and CHL1 in the ENU register provide a loopback
feature for diagnostic testing of the USART. When both bits
are set to one, the following occurs: The receiver input pin
(RDX) is internally connected to the transmitter output pin
(TDX); the output of the Transmitter Shift Register is “looped
back” into the Receive Shift Register input. In this mode,
data that is transmitted is immediately received. This feature
allows the processor to verify the transmit and receive data
paths of the USART.
14.11 BREAK GENERATION
To generate a line break, the user software should set the
BRK bit in the ENUI register. This will force the TDX pin to 0
and hold it there until the BRK bit is reset.
Note that the framing format for this mode is the nine bit
format; one Start bit, nine data bits, and one or two Stop bits.
Parity is not generated or verified in this mode.
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48
The Software trap has the highest priority while the default
VIS has the lowest priority.
15.0 Interrupts
Each of the 13 maskable inputs has a fixed arbitration rank-
ing and vector.
15.1 INTRODUCTION
The device supports eleven vectored interrupts. Interrupt
sources include Timer 1, Timer 2, Timer T0, Port L Wake-up,
Software Trap, MICROWIRE/PLUS, USART and External
Input.
Figure 26 shows the Interrupt block diagram.
All interrupts force a branch to location 00FF Hex in program
memory. The VIS instruction may be used to vector to the
appropriate service routine from location 00FF Hex.
20032765
FIGURE 26. Interrupt Block Diagram
15.2 MASKABLE INTERRUPTS
An interrupt is triggered only when all of these conditions are
met at the beginning of an instruction. If different maskable
interrupts meet these conditions simultaneously, the highest-
priority interrupt will be serviced first, and the other pending
interrupts must wait.
All interrupts other than the Software Trap are maskable.
Each maskable interrupt has an associated enable bit and
pending flag bit. The pending bit is set to 1 when the interrupt
condition occurs. The state of the interrupt enable bit, com-
bined with the GIE bit determines whether an active pending
flag actually triggers an interrupt. All of the maskable inter-
rupt pending and enable bits are contained in mapped con-
trol registers, and thus can be controlled by the software.
Upon Reset, all pending bits, individual enable bits, and the
GIE bit are reset to zero. Thus, a maskable interrupt condi-
tion cannot trigger an interrupt until the program enables it by
setting both the GIE bit and the individual enable bit. When
enabling an interrupt, the user should consider whether or
not a previously activated (set) pending bit should be ac-
knowledged. If, at the time an interrupt is enabled, any
previous occurrences of the interrupt should be ignored, the
associated pending bit must be reset to zero prior to en-
abling the interrupt. Otherwise, the interrupt may be simply
enabled; if the pending bit is already set, it will immediately
trigger an interrupt. A maskable interrupt is active if its asso-
ciated enable and pending bits are set.
A maskable interrupt condition triggers an interrupt under the
following conditions:
1. The enable bit associated with that interrupt is set.
2. The GIE bit is set.
3. The device is not processing a non-maskable interrupt.
(If
a non-maskable interrupt is being serviced, a
maskable interrupt must wait until that service routine is
completed.)
49
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15.3 VIS INSTRUCTION
15.0 Interrupts (Continued)
The general interrupt service routine, which starts at address
00FF Hex, must be capable of handling all types of inter-
rupts. The VIS instruction, together with an interrupt vector
table, directs the device to the specific interrupt handling
routine based on the cause of the interrupt.
An interrupt is an asychronous event which may occur be-
fore, during, or after an instruction cycle. Any interrupt which
occurs during the execution of an instruction is not acknowl-
edged until the start of the next normally executed instruc-
tion. If the next normally executed instruction is to be
skipped, the skip is performed before the pending interrupt is
acknowledged.
VIS is a single-byte instruction, typically used at the very
beginning of the general interrupt service routine at address
00FF Hex, or shortly after that point, just after the code used
for context switching. The VIS instruction determines which
enabled and pending interrupt has the highest priority, and
causes an indirect jump to the address corresponding to that
interrupt source. The jump addresses (vectors) for all pos-
sible interrupts sources are stored in a vector table.
At the start of interrupt acknowledgment, the following ac-
tions occur:
1. The GIE bit is automatically reset to zero, preventing any
subsequent maskable interrupt from interrupting the cur-
rent service routine. This feature prevents one maskable
interrupt from interrupting another one being serviced.
The vector table may be as long as 32 bytes (maximum of 16
vectors) and resides at the top of the 256-byte block con-
taining the VIS instruction. However, if the VIS instruction is
at the very top of a 256-byte block (such as at 00FF Hex),
the vector table resides at the top of the next 256-byte block.
Thus, if the VIS instruction is located somewhere between
00FF and 01DF Hex (the usual case), the vector table is
located between addresses 01E0 and 01FF Hex. If the VIS
instruction is located between 01FF and 02DF Hex, then the
vector table is located between addresses 02E0 and 02FF
Hex, and so on.
2. The address of the instruction about to be executed is
pushed onto the stack.
3. The program counter (PC) is loaded with 00FF Hex,
causing a jump to that program memory location.
The device requires seven instruction cycles to perform the
actions listed above.
If the user wishes to allow nested interrupts, the interrupts
service routine may set the GIE bit to 1 by writing to the PSW
register, and thus allow other maskable interrupts to interrupt
the current service routine. If nested interrupts are allowed,
caution must be exercised. The user must write the program
in such a way as to prevent stack overflow, loss of saved
context information, and other unwanted conditions.
Each vector is 15 bits long and points to the beginning of a
specific interrupt service routine somewhere in the 32-kbyte
memory space. Each vector occupies two bytes of the vector
table, with the higher-order byte at the lower address. The
vectors are arranged in order of interrupt priority. The vector
of the maskable interrupt with the lowest rank is located to
0yE0 (higher-order byte) and 0yE1 (lower-order byte). The
next priority interrupt is located at 0yE2 and 0yE3, and so
forth in increasing rank. The Software Trap has the highest
rand and its vector is always located at 0yFE and 0yFF. The
number of interrupts which can become active defines the
size of the table.
The interrupt service routine stored at location 00FF Hex
should use the VIS instruction to determine the cause of the
interrupt, and jump to the interrupt handling routine corre-
sponding to the highest priority enabled and active interrupt.
Alternately, the user may choose to poll all interrupt pending
and enable bits to determine the source(s) of the interrupt. If
more than one interrupt is active, the user’s program must
decide which interrupt to service.
Within a specific interrupt service routine, the associated
pending bit should be cleared. This is typically done as early
as possible in the service routine in order to avoid missing
the next occurrence of the same type of interrupt event.
Thus, if the same event occurs a second time, even while the
first occurrence is still being serviced, the second occur-
rence will be serviced immediately upon return from the
current interrupt routine.
Table 21 shows the types of interrupts, the interrupt arbitra-
tion ranking, and the locations of the corresponding vectors
in the vector table.
The vector table should be filled by the user with the memory
locations of the specific interrupt service routines. For ex-
ample, if the Software Trap routine is located at 0310 Hex,
then the vector location 0yFE and -0yFF should contain the
data 03 and 10 Hex, respectively. When a Software Trap
interrupt occurs and the VIS instruction is executed, the
program jumps to the address specified in the vector table.
An interrupt service routine typically ends with an RETI
instruction. This instruction set the GIE bit back to 1, pops
the address stored on the stack, and restores that address to
the program counter. Program execution then proceeds with
the next instruction that would have been executed had
there been no interrupt. If there are any valid interrupts
pending, the highest-priority interrupt is serviced immedi-
ately upon return from the previous interrupt.
The interrupt sources in the vector table are listed in order of
rank, from highest to lowest priority. If two or more enabled
and pending interrupts are detected at the same time, the
one with the highest priority is serviced first. Upon return
from the interrupt service routine, the next highest-level
pending interrupt is serviced.
Note: While executing from the Boot ROM for ISP or virtual
E2 operations, the hardware will disable interrupts from oc-
curring. The hardware will leave the GIE bit in its current
state, and if set, the hardware interrupts will occur when
execution is returned to Flash Memory. Subsequent inter-
rupts, during ISP operation, from the same interrupt source
will be lost.
If the VIS instruction is executed, but no interrupts are en-
abled and pending, the lowest-priority interrupt vector is
used, and a jump is made to the corresponding address in
the vector table. This is an unusual occurrence and may be
the result of an error. It can legitimately result from a change
in the enable bits or pending flags prior to the execution of
the VIS instruction, such as executing a single cycle instruc-
tion which clears an enable flag at the same time that the
pending flag is set. It can also result, however, from inad-
vertent execution of the VIS command outside of the context
of an interrupt.
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50
To ensure reliable operation, the user should always use the
VIS instruction to determine the source of an interrupt. Al-
though it is possible to poll the pending bits to detect the
source of an interrupt, this practice is not recommended. The
use of polling allows the standard arbitration ranking to be
altered, but the reliability of the interrupt system is compro-
mised. The polling routine must individually test the enable
and pending bits of each maskable interrupt. If a Software
Trap interrupt should occur, it will be serviced last, even
though it should have the highest priority. Under certain
conditions, a Software Trap could be triggered but not ser-
viced, resulting in an inadvertent “locking out” of all
maskable interrupts by the Software Trap pending flag.
Problems such as this can be avoided by using VIS
instruction.
15.0 Interrupts (Continued)
The default VIS interrupt vector can be useful for applica-
tions in which time critical interrupts can occur during the
servicing of another interrupt. Rather than restoring the pro-
gram context (A, B, X, etc.) and executing the RETI instruc-
tion, an interrupt service routine can be terminated by return-
ing to the VIS instruction. In this case, interrupts will be
serviced in turn until no further interrupts are pending and
the default VIS routine is started. After testing the GIE bit to
ensure that execution is not erroneous, the routine should
restore the program context and execute the RETI to return
to the interrupted program.
This technique can save up to fifty instruction cycles (tC), or
more, (50 µs at 10 MHz oscillator) of latency for pending
interrupts with a penalty of fewer than ten instruction cycles
if no further interrupts are pending.
TABLE 19. Interrupt Vector Table
Source Description
Vector Address (Note 18)
Arbitration Ranking
(Hi-Low Byte)
(1) Highest
(2)
Software
INTR Instruction
0yFE–0yFF
Reserved for NMI
External
0yFC–0yFD
0yFA–0yFB
0yF8–0yF9
0yF6–0yF7
0yF4–0yF5
0yF2–0yF3
0yF0–0yF1
0yEE–0yEF
0yEC–0yED
0yEA–0yEB
0yE8–0yE9
0yE6–0yE7
0yE4–0yE5
0yE2–0yE3
0yE0–0yE1
(3)
G0
(4)
Timer T0
Underflow
T1A/Underflow
T1B
(5)
Timer T1
(6)
Timer T1
(7)
MICROWIRE/PLUS
Reserved
BUSY Low
(8)
(9)
USART
Receive
(10)
(11)
USART
Transmit
T2A/Underflow
T2B
Timer T2
(12)
(13)
(14)
(15)
(16) Lowest
Timer T2
Reserved
Reserved
Port L/Wake-up
Default VIS
Port L Edge
Reserved
Note 18: y is a variable which represents the VIS block. VIS and the vector table must be located in the same 256-byte block except if VIS is located at the last
address of a block. In this case, the table must be in the next block.
15.3.1 VIS Execution
the active interrupt with the highest arbitration ranking. This
vector is read from program memory and placed into the PC
which is now pointed to the 1st instruction of the service
routine of the active interrupt with the highest arbitration
ranking.
When the VIS instruction is executed it activates the arbitra-
tion logic. The arbitration logic generates an even number
between E0 and FE (E0, E2, E4, E6 etc....) depending on
which active interrupt has the highest arbitration ranking at
the time of the 1st cycle of VIS is executed. For example, if
the software trap interrupt is active, FE is generated. If the
external interrupt is active and the software trap interrupt is
not, then FA is generated and so forth. If no active interrupt
is pending, than E0 is generated. This number replaces the
lower byte of the PC. The upper byte of the PC remains
unchanged. The new PC is therefore pointing to the vector of
Figure 27 illustrates the different steps performed by the VIS
instruction. Figure 28 shows a flowchart for the VIS instruc-
tion.
The non-maskable interrupt pending flag is cleared by the
RPND (Reset Non-Maskable Pending Bit) instruction (under
certain conditions) and upon RESET.
51
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15.0 Interrupts (Continued)
20032733
FIGURE 27. VIS Operation
15.4 NON-MASKABLE INTERRUPT
15.4.1 Pending Flag
Nothing can interrupt a Software Trap service routine except
for another Software Trap. The STPND can be reset only by
the RPND instruction or a chip Reset.
There is a pending flag bit associated with the non-maskable
Software Trap interrupt, called STPND. This pending flag is
not memory-mapped and cannot be accessed directly by the
software.
The Software Trap indicates an unusual or unknown error
condition. Generally, returning to normal execution at the
point where the Software Trap occurred cannot be done
reliably. Therefore, the Software Trap service routine should
re-initialize the stack pointer and perform a recovery proce-
dure that re-starts the software at some known point, similar
to a device Reset, but not necessarily performing all the
same functions as a device Reset. The routine must also
execute the RPND instruction to reset the STPND flag.
Otherwise, all other interrupts will be locked out. To the
extent possible, the interrupt routine should record or indi-
cate the context of the device so that the cause of the
Software Trap can be determined.
The pending flag is reset to zero when a device Reset
occurs. When the non-maskable interrupt occurs, the asso-
ciated pending bit is set to 1. The interrupt service routine
should contain an RPND instruction to reset the pending flag
to zero. The RPND instruction always resets the STPND
flag.
15.4.2 Software Trap
The Software Trap is a special kind of non-maskable inter-
rupt which occurs when the INTR instruction (used to ac-
knowledge interrupts) is fetched from program memory and
placed in the instruction register. This can happen in a
variety of ways, usually because of an error condition. Some
examples of causes are listed below.
If the user wishes to return to normal execution from the
point at which the Software Trap was triggered, the user
must first execute RPND, followed by RETSK rather than
RETI or RET. This is because the return address stored on
the stack is the address of the INTR instruction that triggered
the interrupt. The program must skip that instruction in order
to proceed with the next one. Otherwise, an infinite loop of
Software Traps and returns will occur.
If the program counter incorrectly points to a memory loca-
tion beyond the programmed Flash memory space, the un-
used memory location returns zeros which is interpreted as
the INTR instruction.
Programming a return to normal execution requires careful
consideration. If the Software Trap routine is interrupted by
another Software Trap, the RPND instruction in the service
routine for the second Software Trap will reset the STPND
flag; upon return to the first Software Trap routine, the
STPND flag will have the wrong state. This will allow
maskable interrupts to be acknowledged during the servicing
of the first Software Trap. To avoid problems such as this, the
A Software Trap can be triggered by a temporary hardware
condition such as a brownout or power supply glitch.
The Software Trap has the highest priority of all interrupts.
When a Software Trap occurs, the STPND bit is set. The GIE
bit is not affected and the pending bit (not accessible by the
user) is used to inhibit other interrupts and to direct the
program to the ST service routine with the VIS instruction.
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52
programming error or hardware condition (brownout, power
supply glitch, etc.) sets the STPND flag without providing a
way for it to be cleared, all other interrupts will be locked out.
To alleviate this condition, the user can use extra RPND
instructions in the main program and in the Watchdog ser-
vice routine (if present). There is no harm in executing extra
RPND instructions in these parts of the program.
15.0 Interrupts (Continued)
user program should contain the Software Trap routine to
perform a recovery procedure rather than a return to normal
execution.
Under normal conditions, the STPND flag is reset by a
RPND instruction in the Software Trap service routine. If a
20032734
FIGURE 28. VIS Flow Chart
15.4.2.1 Programming Example: External Interrupt
PSW
CNTRL
RBIT
RBIT
SBIT
SBIT
SBIT
JP
=00EF
=00EE
0,PORTGC
0,PORTGD
IEDG, CNTRL
GIE, PSW
EXEN, PSW
WAIT
; G0 pin configured Hi-Z
; Ext interrupt polarity; falling edge
; Set the GIE bit
; Enable the external interrupt
; Wait for external interrupt
WAIT:
.
.
.
.=0FF
VIS
; The interrupt causes a
; branch to address 0FF
; The VIS causes a branch to
; interrupt vector table
.
.
.
.=01FA
.ADDRW SERVICE
; Vector table (within 256 byte
; of VIS inst.) containing the ext
; interrupt service routine
.
.
.
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15.0 Interrupts (Continued)
SERVICE:
; Interrupt Service Routine
RBIT,EXPND,PSW
; Reset ext interrupt pend. bit
.
.
.
RET I
; Return, set the GIE bit
15.5 PORT L INTERRUPTS
state, and if set, the hardware interrupts will occur when
execution is returned to Flash Memory. Subsequent in-
terrupts, during ISP operation, from the same interrupt
source will be lost.
Port L provides the user with an additional eight fully select-
able, edge sensitive interrupts which are all vectored into the
same service subroutine.
The interrupt from Port L shares logic with the wake-up
circuitry. The register WKEN allows interrupts from Port L to
be individually enabled or disabled. The register WKEDG
specifies the trigger condition to be either a positive or a
negative edge. Finally, the register WKPND latches in the
pending trigger conditions.
16.0 WATCHDOG/Clock Monitor
The devices contain a user selectable WATCHDOG and
clock monitor. The following section is applicable only if the
WATCHDOG feature has been selected in the Option regis-
ter. The WATCHDOG is designed to detect the user program
getting stuck in infinite loops resulting in loss of program
control or “runaway” programs.
The GIE (Global Interrupt Enable) bit enables the interrupt
function.
The WATCHDOG logic contains two separate service win-
dows. While the user programmable upper window selects
the WATCHDOG service time, the lower window provides
protection against an infinite program loop that contains the
WATCHDOG service instruction. The WATCHDOG uses the
Idle Timer (T0) and thus all times are measured in Idle Timer
Clocks.
A control flag, LPEN, functions as a global interrupt enable
for Port L interrupts. Setting the LPEN flag will enable inter-
rupts and vice versa. A separate global pending flag is not
needed since the register WKPND is adequate.
Since Port L is also used for waking the device out of the
HALT or IDLE modes, the user can elect to exit the HALT or
IDLE modes either with or without the interrupt enabled. If he
elects to disable the interrupt, then the device will restart
execution from the instruction immediately following the in-
struction that placed the microcontroller in the HALT or IDLE
modes. In the other case, the device will first execute the
interrupt service routine and then revert to normal operation.
(See HALT MODE for clock option wake-up information.)
The Clock Monitor is used to detect the absence of a clock or
a very slow clock below a specified rate on tC.
The WATCHDOG consists of two independent logic blocks:
WD UPPER and WD LOWER. WD UPPER establishes the
upper limit on the service window and WD LOWER defines
the lower limit of the service window.
Servicing the WATCHDOG consists of writing a specific
value to a WATCHDOG Service Register named WDSVR
which is memory mapped in the RAM. This value is com-
posed of three fields, consisting of a 2-bit Window Select, a
5-bit Key Data field, and the 1-bit Clock Monitor Select field.
Table 20 shows the WDSVR register.
15.6 INTERRUPT SUMMARY
The device uses the following types of interrupts, listed
below in order of priority:
1. The Software Trap non-maskable interrupt, triggered by
the INTR (00 opcode) instruction. The Software Trap is
acknowledged immediately. This interrupt service rou-
tine can be interrupted only by another Software Trap.
The Software Trap should end with two RPND instruc-
tions followed by a re-start procedure.
TABLE 20. WATCHDOG Service Register (WDSVR)
Window
Select
Clock
Monitor
Key Data
2. Maskable interrupts, triggered by an on-chip peripheral
block or an external device connected to the device.
Under ordinary conditions, a maskable interrupt will not
interrupt any other interrupt routine in progress. A
maskable interrupt routine in progress can be inter-
X
7
X
6
0
5
1
4
1
3
0
2
0
1
Y
0
The lower limit of the service window is fixed at 2048 Idle
Timer Clocks. Bits 7 and 6 of the WDSVR register allow the
user to pick an upper limit of the service window.
rupted by the non-maskable interrupt request.
A
maskable interrupt routine should end with an RETI
instruction or, prior to restoring context, should return to
execute the VIS instruction. This is particularly useful
when exiting long interrupt service routines if the time
between interrupts is short. In this case the RETI instruc-
tion would only be executed when the default VIS rou-
tine is reached.
Table 21 shows the four possible combinations of lower and
upper limits for the WATCHDOG service window. This flex-
ibility in choosing the WATCHDOG service window prevents
any undue burden on the user software.
Bits 5, 4, 3, 2 and 1 of the WDSVR register represent the
5-bit Key Data field. The key data is fixed at 01100. Bit 0 of
the WDSVR Register is the Clock Monitor Select bit.
3. While executing from the Boot ROM for ISP or virtual E2
operations, the hardware will disable interrupts from oc-
curring. The hardware will leave the GIE bit in its current
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54
16.0 WATCHDOG/Clock Monitor (Continued)
TABLE 21. WATCHDOG Service Window Select
Clock
Monitor
Bit 0
Service Window
for High Speed Mode
(Lower-Upper Limits)
Service Window
for Dual Clock & Low Speed Modes
(Lower-Upper Limits)
WDSVR
Bit 7
WDSVR
Bit 6
0
0
1
1
X
X
0
1
0
1
X
X
X
X
X
X
0
2048-8k tC Cycles
2048-8k Cycles of 32 kHz Clk
2048-16k Cycles of LS 32 kHz Clk
2048-32k Cycles of LS 32 kHz Clk
2048-64k Cycles of LS 32 kHz Clk
Clock Monitor Disabled
2048-16k tC Cycles
2048-32k tC Cycles
2048-64k tC Cycles
Clock Monitor Disabled
Clock Monitor Enabled
1
Clock Monitor Enabled
16.1 CLOCK MONITOR
When jumping to the boot ROM for ISP and virtual E2
operations, the hardware will disable the lower window error
and perform an immediate WATCHDOG service. The ISP
routines will service the WATCHDOG within the selected
upper window. The ISP routines will service the WATCH-
DOG immediately prior to returning execution back to the
user’s code in flash. Therefore, after returning to flash
memory, the user can service the WATCHDOG anytime
following the return from boot ROM, but must service it within
the selected upper window to avoid a WATCHDOG error.
The Clock Monitor aboard the device can be selected or
deselected under program control. The Clock Monitor is
guaranteed not to reject the clock if the instruction cycle
clock (1/tC) is greater or equal to 5 kHz. This equates to a
clock input rate on the selected oscillator of greater or equal
to 25 kHz.
16.2 WATCHDOG/CLOCK MONITOR OPERATION
The WATCHDOG is enabled by bit 2 of the Option register.
When this Option bit is 0, the WATCHDOG is enabled and
pin G1 becomes the WATCHDOG output with a weak pull-
up.
The WATCHDOG has an output pin associated with it. This
is the WDOUT pin, on pin 1 of the port G. WDOUT is active
low. The WDOUT pin has a weak pull-up in the inactive
state. Upon triggering the WATCHDOG, the logic will pull the
WDOUT (G1) pin low for an additional 16–32 cycles after the
signal level on WDOUT pin goes below the lower Schmitt
trigger threshold. After this delay, the device will stop forcing
the WDOUT output low. The WATCHDOG service window
will restart when the WDOUT pin goes high.
The WATCHDOG and Clock Monitor are disabled during
reset. The device comes out of reset with the WATCHDOG
armed, the WATCHDOG Window Select bits (bits 6, 7 of the
WDSVR Register) set, and the Clock Monitor bit (bit 0 of the
WDSVR Register) enabled. Thus, a Clock Monitor error will
occur after coming out of reset, if the instruction cycle clock
frequency has not reached a minimum specified value, in-
cluding the case where the oscillator fails to start.
A WATCHDOG service while the WDOUT signal is active will
be ignored. The state of the WDOUT pin is not guaranteed
on reset, but if it powers up low then the WATCHDOG will
time out and WDOUT will go high.
The WDSVR register can be written to only once after reset
and the key data (bits 5 through 1 of the WDSVR Register)
must match to be a valid write. This write to the WDSVR
register involves two irrevocable choices: (i) the selection of
the WATCHDOG service window (ii) enabling or disabling of
the Clock Monitor. Hence, the first write to WDSVR Register
involves selecting or deselecting the Clock Monitor, select
the WATCHDOG service window and match the WATCH-
DOG key data. Subsequent writes to the WDSVR register
will compare the value being written by the user to the
WATCHDOG service window value, the key data and the
Clock Monitor Enable (all bits) in the WDSVR Register. Table
22 shows the sequence of events that can occur.
The Clock Monitor forces the G1 pin low upon detecting a
clock frequency error. The Clock Monitor error will continue
until the clock frequency has reached the minimum specified
value, after which the G1 output will go high following 16–32
clock cycles. The Clock Monitor generates a continual Clock
Monitor error if the oscillator fails to start, or fails to reach the
minimum specified frequency. The specification for the Clock
Monitor is as follows:
>
1/tC 5 kHz—No clock rejection.
<
1/tC 10 Hz—Guaranteed clock rejection.
The user must service the WATCHDOG at least once before
the upper limit of the service window expires. The
WATCHDOG may not be serviced more than once in every
lower limit of the service window.
TABLE 22. WATCHDOG Service Actions
Key
Data
Window
Data
Clock
Monitor
Match
Action
Match
Match
Valid Service: Restart Service Window
Don’t Care
Mismatch
Don’t Care
Mismatch
Don’t Care
Don’t Care
Don’t Care Error: Generate WATCHDOG Output
Don’t Care Error: Generate WATCHDOG Output
Mismatch
Error: Generate WATCHDOG Output
55
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lected upper window. Upon return to flash memory, the
WATCHDOG is serviced, the lower window is enabled,
and the user can service the WATCHDOG anytime fol-
lowing exit from Boot ROM, but must service it within the
selected upper window to avoid a WATCHDOG error.
16.0 WATCHDOG/Clock Monitor
(Continued)
16.3 WATCHDOG AND CLOCK MONITOR SUMMARY
The following salient points regarding the WATCHDOG and
CLOCK MONITOR should be noted:
16.4 DETECTION OF ILLEGAL CONDITIONS
•
Both the WATCHDOG and CLOCK MONITOR detector
circuits are inhibited during RESET.
The device can detect various illegal conditions resulting
from coding errors, transient noise, power supply voltage
drops, runaway programs, etc.
•
Following RESET, the WATCHDOG and CLOCK MONI-
TOR are both enabled, with the WATCHDOG having the
maximum service window selected.
Reading of unprogrammed ROM gets zeros. The opcode for
software interrupt is 00. If the program fetches instructions
from unprogrammed ROM, this will force a software inter-
rupt, thus signaling that an illegal condition has occurred.
•
•
•
•
The WATCHDOG service window and CLOCK MONI-
TOR enable/disable option can only be changed once,
during the initial WATCHDOG service following RESET.
The subroutine stack grows down for each call (jump to
subroutine), interrupt, or PUSH, and grows up for each
return or POP. The stack pointer is initialized to RAM location
06F Hex during reset. Consequently, if there are more re-
turns than calls, the stack pointer will point to addresses 070
and 071 Hex (which are undefined RAM). Undefined RAM
from addresses 070 to 07F (Segment 0), and all other seg-
ments (i.e., Segments 4... etc.) is read as all 1’s, which in
turn will cause the program to return to address 7FFF Hex.
This location is unimplemented and, when accessed by an
instruction fetch, will respond with an INTR instruction (all
0’s) to generate a software interrupt, signalling an illegal
condition on overpop of the stack.
The initial WATCHDOG service must match the key data
value in the WATCHDOG Service register WDSVR in
order to avoid a WATCHDOG error.
Subsequent WATCHDOG services must match all three
data fields in WDSVR in order to avoid WATCHDOG
errors.
The correct key data value cannot be read from the
WATCHDOG Service register WDSVR. Any attempt to
read this key data value of 01100 from WDSVR will read
as key data value of all 0’s.
•
•
The WATCHDOG detector circuit is inhibited during both
the HALT and IDLE modes.
Thus, the chip can detect the following illegal conditions:
1. Executing from undefined Program Memory
The CLOCK MONITOR detector circuit is active during
both the HALT and IDLE modes. Consequently, the de-
vice inadvertently entering the HALT mode will be de-
tected as a CLOCK MONITOR error (provided that the
CLOCK MONITOR enable option has been selected by
the program). Likewise, a device with WATCHDOG en-
abled in the Option but with the WATCHDOG output not
connected to RESET, will draw excessive HALT current if
placed in the HALT mode. The clock Monitor will pull the
WATCHDOG output low and sink current through the
on-chip pull-up resistor.
2. Over “POP”ing the stack by having more returns than
calls.
When the software interrupt occurs, the user can re-initialize
the stack pointer and do a recovery procedure before restart-
ing (this recovery program is probably similar to that follow-
ing reset, but might not contain the same program initializa-
tion procedures). The recovery program should reset the
software interrupt pending bit using the RPND instruction.
•
The WATCHDOG service window will be set to its se-
lected value from WDSVR following HALT. Consequently,
the WATCHDOG should not be serviced for at least 2048
Idle Timer clocks following HALT, but must be serviced
within the selected window to avoid a WATCHDOG error.
17.0 MICROWIRE/PLUS
MICROWIRE/PLUS is a serial SPI compatible synchronous
communications interface. The MICROWIRE/PLUS capabil-
ity enables the device to interface with MICROWIRE/PLUS
or SPI peripherals (i.e. display drivers, EEPROMs etc.) and
with other microcontrollers which support the MICROWIRE/
PLUS or SPI interface. It consists of an 8-bit serial shift
register (SIO) with serial data input (SI), serial data output
(SO) and serial shift clock (SK). Figure 29 shows a block
diagram of the MICROWIRE/PLUS logic.
•
•
The IDLE timer T0 is not initialized with external RESET.
The user can sync in to the IDLE counter cycle with an
IDLE counter (T0) interrupt or by monitoring the T0PND
flag. The T0PND flag is set whenever the selected bit of
the IDLE counter toggles (every 4, 8, 16, 32 or 64k Idle
Timer clocks). The user is responsible for resetting the
T0PND flag.
The shift clock can be selected from either an internal source
or an external source. Operating the MICROWIRE/PLUS
arrangement with the internal clock source is called the
Master mode of operation. Similarly, operating the
MICROWIRE/PLUS arrangement with an external shift clock
is called the Slave mode of operation.
•
•
A hardware WATCHDOG service occurs just as the de-
vice exits the IDLE mode. Consequently, the
WATCHDOG should not be serviced for at least 2048 Idle
Timer clocks following IDLE, but must be serviced within
the selected window to avoid a WATCHDOG error.
The CNTRL register is used to configure and control the
MICROWIRE/PLUS mode. To use the MICROWIRE/PLUS,
the MSEL bit in the CNTRL register is set to one. In the
master mode, the SK clock rate is selected by the two bits,
SL0 and SL1, in the CNTRL register. Table 23 details the
different clock rates that may be selected.
Following RESET, the initial WATCHDOG service (where
the service window and the CLOCK MONITOR enable/
disable must be selected) may be programmed any-
where within the maximum service window (65,536 in-
struction cycles) initialized by RESET. Note that this initial
WATCHDOG service may be programmed within the ini-
tial 2048 instruction cycles without causing
WATCHDOG error.
a
•
When using any of the ISP functions in Boot ROM, the
ISP routines will service the WATCHDOG within the se-
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56
SK functions onto the G Port. The SO and SK pins must also
be selected as outputs by setting appropriate bits in the Port
G configuration register. In the slave mode, the shift clock
stops after 8 clock pulses. Table 24 summarizes the bit
settings required for Master mode of operation.
17.0 MICROWIRE/PLUS (Continued)
TABLE 23. MICROWIRE/PLUS
Master Mode Clock Select
SL1
0
SL0
SK Period
2 x tC
0
1
x
17.1.2 MICROWIRE/PLUS Slave Mode Operation
In the MICROWIRE/PLUS Slave mode of operation the SK
clock is generated by an external source. Setting the MSEL
bit in the CNTRL register enables the SO and SK functions
onto the G Port. The SK pin must be selected as an input
and the SO pin is selected as an output pin by setting and
resetting the appropriate bits in the Port G configuration
register. Table 24 summarizes the settings required to enter
the Slave mode of operation.
0
4 x tC
1
8 x tC
Where t is the instruction cycle clock
C
17.1 MICROWIRE/PLUS OPERATION
Setting the BUSY bit in the PSW register causes the
MICROWIRE/PLUS to start shifting the data. It gets reset
when eight data bits have been shifted. The user may reset
the BUSY bit by software to allow less than 8 bits to shift. If
enabled, an interrupt is generated when eight data bits have
been shifted. The device may enter the MICROWIRE/PLUS
mode either as a Master or as a Slave. Figure 29 shows how
two microcontroller devices and several peripherals may be
interconnected using the MICROWIRE/PLUS arrangements.
TABLE 24. MICROWIRE/PLUS Mode Settings
This table assumes that the control flag MSEL is set.
G4 (SO)
G5 (SK)
G4
Fun.
SO
G5
Operation
Config. Bit Config. Bit
Fun.
1
0
1
0
1
1
0
0
Int. MICROWIRE/PLUS
SK Master
Warning:
The SIO register should only be loaded when the SK clock is
in the idle phase. Loading the SIO register while the SK clock
is in the active phase, will result in undefined data in the SIO
register.
TRI-
STATE
SO
Int. MICROWIRE/PLUS
SK Master
Ext. MICROWIRE/PLUS
SK Slave
Setting the BUSY flag when the input SK clock is in the
active phase while in the MICROWIRE/PLUS is in the slave
mode may cause the current SK clock for the SIO shift
register to be narrow. For safety, the BUSY flag should only
be set when the input SK clock is in the idle phase.
TRI-
Ext. MICROWIRE/PLUS
SK Slave
STATE
The user must set the BUSY flag immediately upon entering
the Slave mode. This ensures that all data bits sent by the
Master is shifted properly. After eight clock pulses the BUSY
flag is clear, the shift clock is stopped, and the sequence
may be repeated.
17.1.1 MICROWIRE/PLUS Master Mode Operation
In the MICROWIRE/PLUS Master mode of operation the
shift clock (SK) is generated internally. The MICROWIRE/
PLUS Master always initiates all data exchanges. The MSEL
bit in the CNTRL register must be set to enable the SO and
20032735
FIGURE 29. MICROWIRE/PLUS Application
57
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SK clock. In the alternate SK phase operation, data is shifted
in on the falling edge of the SK clock and shifted out on the
rising edge of the SK clock. Bit 6 of Port G configuration
register selects the SK edge.
17.0 MICROWIRE/PLUS (Continued)
17.1.2.1 Alternate SK Phase Operation and SK Idle
Polarity
The device allows either the normal SK clock or an alternate
phase SK clock to shift data in and out of the SIO register. In
both the modes the SK idle polarity can be either high or low.
The polarity is selected by bit 5 of Port G data register. In the
normal mode data is shifted in on the rising edge of the SK
clock and the data is shifted out on the falling edge of the SK
clock. The SIO register is shifted on each falling edge of the
A control flag, SKSEL, allows either the normal SK clock or
the alternate SK clock to be selected. Refer to Table 25 for
the appropriate setting of the SKSEL bit. The SKSEL is
mapped into the G6 configuration bit. The SKSEL flag will
power up in the reset condition, selecting the normal SK
signal provided the SK Idle Polarity remains LOW.
TABLE 25. MICROWIRE/PLUS Shift Clock Polarity and Sample/Shift Phase
Port G
G6 (SKSEL)
SK Idle
Phase
SO Clocked Out On:
SI Sampled On:
SK Phase
G5 Data
Config. Bit
Bit
0
Normal
Alternate
Alternate
Normal
0
1
0
1
SK Falling Edge
SK Rising Edge
SK Rising Edge
SK Falling Edge
SK Rising Edge
SK Falling Edge
SK Falling Edge
SK Rising Edge
Low
Low
High
High
0
1
1
20032736
FIGURE 30. MICROWIRE/PLUS SPI Mode Interface Timing, Normal SK Mode, SK Idle Phase being Low
20032737
FIGURE 31. MICROWIRE/PLUS SPI Mode Interface Timing, Alternate SK Mode, SK Idle Phase being Low
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17.0 MICROWIRE/PLUS (Continued)
20032738
FIGURE 32. MICROWIRE/PLUS SPI Mode Interface Timing, Normal SK Mode, SK Idle Phase being High
20032739
FIGURE 33. MICROWIRE/PLUS SPI Mode Interface Timing, Alternate SK Mode, SK Idle Phase being High
18.0 Memory Map
All RAM, ports and registers (except A and PC) are mapped
into data memory address space.
Address
Contents
S/ADD REG
xxAD
Reserved
xxAE
xxAF
Reserved
Address
Contents
High Speed Timers Control Register
(HSTCR)
S/ADD REG
0000 to 006F On-Chip RAM bytes (112 bytes)
0070 to 007F Unused RAM Address Space (Reads As
All Ones)
xxB0 to xxB7 Reserved
xxB8
xxB9
xxBA
USART Transmit Buffer (TBUF)
USART Receive Buffer (RBUF)
USART Control and Status Register
(ENU)
xx80 to xx8F
Unused RAM Address Space (Reads
Undefined Data)
xx90 to xx9F
xxA0
Reserved
xxBB
xxBC
USART Receive Control and Status
Register (ENUR)
Port A Data Register
xxA1
Port A Configuration Register
Port A Input Pins (Read Only)
Reserved for Port A
USART Interrupt and Clock Source
Register (ENUI)
xxA2
xxA3
xxBD
xxBE
xxBF
xxC0
xxC1
xxC2
USART Baud Register (BAUD)
USART Prescale Select Register (PSR)
Reserved for USART
xxA4
Port B Data Register
xxA5
Port B Configuration Register
Port B Input Pins (Read Only)
Reserved for Port B
xxA6
Timer T2 Lower Byte
xxA7
Timer T2 Upper Byte
xxA8
ISP Address Register Low Byte
(ISPADLO)
Timer T2 Autoload Register T2RA Lower
Byte
xxA9
ISP Address Register High Byte
(ISPADHI)
xxC3
xxC4
Timer T2 Autoload Register T2RA Upper
Byte
xxAA
xxAB
xxAC
ISP Read Data Register (ISPRD)
ISP Write Data Register (ISPWR)
Reserved
Timer T2 Autoload Register T2RB Lower
Byte
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Note: Reading memory locations 0070H–007FH (Segment 0) will return all
ones. Reading unused memory locations 0080H–0093H (Segment 0)
will return undefined data. Reading memory locations from other Seg-
ments (i.e., Segment 8, Segment 9, … etc.) will return undefined data.
18.0 Memory Map (Continued)
Address
Contents
S/ADD REG
19.0 Instruction Set
xxC5
Timer T2 Autoload Register T2RB Upper
Byte
19.1 INTRODUCTION
xxC6
xxC7
Timer T2 Control Register
WATCHDOG Service Register
(Reg:WDSVR)
This section defines the instruction set of the COP8 Family
members. It contains information about the instruction set
features, addressing modes and types.
xxC8
MIWU Edge Select Register
(Reg:WKEDG)
19.2 INSTRUCTION FEATURES
The strength of the instruction set is based on the following
features:
xxC9
xxCA
MIWU Enable Register (Reg:WKEN)
MIWU Pending Register (Reg:WKPND)
•
•
•
•
•
•
Mostly single-byte opcode instructions minimize program
size.
xxCB to xxCE Reserved
One instruction cycle for the majority of single-byte in-
structions to minimize program execution time.
xxCF
xxD0
xxD1
xxD2
xxD3
xxD4
xxD5
xxD6
Idle Timer Control Register (ITMR)
Port L Data Register
Many single-byte, multiple function instructions such as
DRSZ.
Port L Configuration Register
Port L Input Pins (Read Only)
Reserved for Port L
Three memory mapped pointers: two for register indirect
addressing, and one for the software stack.
Port G Data Register
Sixteen memory mapped registers that allow an opti-
mized implementation of certain instructions.
Port G Configuration Register
Port G Input Pins (Read Only)
Ability to set, reset, and test any individual bit in data
memory address space, including the memory-mapped
I/O ports and registers.
xxD7 to xxDB Reserved
xxDC
xxDD
xxDE
xxDF
xxE0
xxE1
Port H Data Register
•
•
Register-Indirect LOAD and EXCHANGE instructions
with optional automatic post-incrementing or decrement-
ing of the register pointer. This allows for greater effi-
ciency (both in cycle time and program code) in loading,
walking across and processing fields in data memory.
Port H Configuration Register
Port H Input Pins (Read Only)
Reserved for Port H
Reserved
Unique instructions to optimize program size and
throughput efficiency. Some of these instructions are:
DRSZ, IFBNE, DCOR, RETSK, VIS and RRC.
Flash Memory Write Timing Register
(PGMTIM)
xxE2
ISP Key Register (ISPKEY)
19.3 ADDRESSING MODES
xxE3 to xxE5 Reserved
The instruction set offers a variety of methods for specifying
memory addresses. Each method is called an addressing
mode. These modes are classified into two categories: op-
erand addressing modes and transfer-of-control addressing
modes. Operand addressing modes are the various meth-
ods of specifying an address for accessing (reading or writ-
ing) data. Transfer-of-control addressing modes are used in
conjunction with jump instructions to control the execution
sequence of the software program.
xxE6
Timer T1 Autoload Register T1RB Lower
Byte
xxE7
Timer T1 Autoload Register T1RB Upper
Byte
xxE8
xxE9
xxEA
xxEB
xxEC
ICNTRL Register
MICROWIRE/PLUS Shift Register
Timer T1 Lower Byte
Timer T1 Upper Byte
Timer T1 Autoload Register T1RA Lower
Byte
19.3.1 Operand Addressing Modes
The operand of an instruction specifies what memory loca-
tion is to be affected by that instruction. Several different
operand addressing modes are available, allowing memory
locations to be specified in a variety of ways. An instruction
can specify an address directly by supplying the specific
address, or indirectly by specifying a register pointer. The
contents of the register (or in some cases, two registers)
point to the desired memory location. In the immediate
mode, the data byte to be used is contained in the instruction
itself.
xxED
Timer T1 Autoload Register T1RA Upper
Byte
xxEE
xxEF
CNTRL Control Register
PSW Register
xxF0 to xxFB On-Chip RAM Mapped as Registers
xxFC
xxFD
xxFE
xxFF
X Register
SP Register
B Register
S Register
Each addressing mode has its own advantages and disad-
vantages with respect to flexibility, execution speed, and
program compactness. Not all modes are available with all
instructions. The Load (LD) instruction offers the largest
number of addressing modes.
0100 to 017F On-Chip 128 RAM Bytes
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number sign character (#) indicates an immediate operand.
Example: Load Accumulator Immediate
LD A,#05
19.0 Instruction Set (Continued)
The available addressing modes are:
•
•
•
Direct
Reg/Data
Memory
Contents
Before
Contents
After
Register B or X Indirect
Register
B or X Indirect with Post-Incrementing/
Accumulator
XX Hex
05 Hex
Decrementing
•
•
•
Immediate
Immediate Short. This is a special case of an immediate
instruction. In the “Load B immediate” instruction, the 4-bit
immediate value in the instruction is loaded into the lower
nibble of the B register. The upper nibble of the B register is
reset to 0000 binary.
Immediate Short
Indirect from Program Memory
The addressing modes are described below. Each descrip-
tion includes an example of an assembly language instruc-
tion using the described addressing mode.
Example: Load B Register Immediate Short
LD B,#7
Direct. The memory address is specified directly as a byte in
the instruction. In assembly language, the direct address is
written as a numerical value (or a label that has been defined
elsewhere in the program as a numerical value).
Reg/Data
Memory
B Pointer
Contents
Before
Contents
After
Example: Load Accumulator Memory Direct
LD A,05
12 Hex
07 Hex
Indirect from Program Memory. This is a special case of
an indirect instruction that allows access to data tables
stored in program memory. In the “Load Accumulator Indi-
rect” (LAID) instruction, the upper and lower bytes of the
Program Counter (PCU and PCL) are used temporarily as a
pointer to program memory. For purposes of accessing pro-
gram memory, the contents of the Accumulator and PCL are
exchanged. The data pointed to by the Program Counter is
loaded into the Accumulator, and simultaneously, the original
contents of PCL are restored so that the program can re-
sume normal execution.
Reg/Data
Memory
Contents
Before
Contents
After
Accumulator
Memory Location
0005 Hex
XX Hex
A6 Hex
A6 Hex
A6 Hex
Register B or X Indirect. The memory address is specified
by the contents of the B Register or X register (pointer
register). In assembly language, the notation [B] or [X] speci-
fies which register serves as the pointer.
Example: Load Accumulator Indirect
LAID
Example: Exchange Memory with Accumulator, B Indirect
X A,[B]
Reg/Data
Memory
Contents
Before
04 Hex
35 Hex
1F Hex
Contents
After
Reg/Data
Memory
Contents
Before
Contents
After
PCU
04 Hex
36 Hex
25 Hex
Accumulator
Memory Location
0005 Hex
01 Hex
87 Hex
PCL
Accumulator
Memory Location
041F Hex
87 Hex
05 Hex
01 Hex
05 Hex
25 Hex
25 Hex
B Pointer
Register
B or X Indirect with Post-Incrementing/
19.3.2 Tranfer-of-Control Addressing Modes
Decrementing. The relevant memory address is specified
by the contents of the B Register or X register (pointer
register). The pointer register is automatically incremented
or decremented after execution, allowing easy manipulation
of memory blocks with software loops. In assembly lan-
guage, the notation [B+], [B−], [X+], or [X−] specifies which
register serves as the pointer, and whether the pointer is to
be incremented or decremented.
Program instructions are usually executed in sequential or-
der. However, Jump instructions can be used to change the
normal execution sequence. Several transfer-of-control ad-
dressing modes are available to specify jump addresses.
A change in program flow requires a non-incremental
change in the Program Counter contents. The Program
Counter consists of two bytes, designated the upper byte
(PCU) and lower byte (PCL). The most significant bit of PCU
is not used, leaving 15 bits to address the program memory.
Example: Exchange Memory with Accumulator, B Indirect
with Post-Increment
X A,[B+]
Different addressing modes are used to specify the new
address for the Program Counter. The choice of addressing
mode depends primarily on the distance of the jump. Farther
jumps sometimes require more instruction bytes in order to
completely specify the new Program Counter contents.
Reg/Data
Memory
Contents
Before
Contents
After
Accumulator
Memory Location
0005 Hex
03 Hex
62 Hex
The available transfer-of-control addressing modes are:
62 Hex
05 Hex
03 Hex
06 Hex
•
•
•
•
Jump Relative
Jump Absolute
Jump Absolute Long
Jump Indirect
B Pointer
Intermediate. The data for the operation follows the instruc-
tion opcode in program memory. In assembly language, the
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19.0 Instruction Set (Continued)
Reg/
Contents
Before
Contents
After
Memory
0126 Hex
The transfer-of-control addressing modes are described be-
low. Each description includes an example of a Jump in-
struction using a particular addressing mode, and the effect
on the Program Counter bytes of executing that instruction.
The VIS instruction is a special case of the Indirect Transfer
of Control addressing mode, where the double-byte vector
associated with the interrupt is transferred from adjacent
addresses in program memory into the Program Counter in
order to jump to the associated interrupt service routine.
Jump Relative. In this 1-byte instruction, six bits of the
instruction opcode specify the distance of the jump from the
current program memory location. The distance of the jump
can range from −31 to +32. A JP+1 instruction is not allowed.
The programmer should use a NOP instead.
19.4 INSTRUCTION TYPES
Example: Jump Relative
JP 0A
The instruction set contains a wide variety of instructions.
The available instructions are listed below, organized into
related groups.
Contents
Before
Contents
After
Reg
Some instructions test a condition and skip the next instruc-
tion if the condition is not true. Skipped instructions are
executed as no-operation (NOP) instructions.
PCU
PCL
02 Hex
05 Hex
02 Hex
0F Hex
19.4.1 Arithmetic Instructions
Jump Absolute. In this 2-byte instruction, 12 bits of the
instruction opcode specify the new contents of the Program
Counter. The upper three bits of the Program Counter re-
main unchanged, restricting the new Program Counter ad-
dress to the same 4-kbyte address space as the current
instruction. (This restriction is relevant only in devices using
more than one 4-kbyte program memory space.)
The arithmetic instructions perform binary arithmetic such as
addition and subtraction, with or without the Carry bit.
Add (ADD)
Add with Carry (ADC)
Subtract with Carry (SUBC)
Increment (INC)
Example: Jump Absolute
JMP 0125
Decrement (DEC)
Decimal Correct (DCOR)
Clear Accumulator (CLR)
Set Carry (SC)
Contents
Before
Contents
After
Reg
Reset Carry (RC)
PCU
PCL
0C Hex
77 Hex
01 Hex
25 Hex
19.4.2 Transfer-of-Control Instructions
The transfer-of-control instructions change the usual se-
quential program flow by altering the contents of the Pro-
gram Counter. The Jump to Subroutine instructions save the
Program Counter contents on the stack before jumping; the
Return instructions pop the top of the stack back into the
Program Counter.
Jump Absolute Long. In this 3-byte instruction, 15 bits of
the instruction opcode specify the new contents of the Pro-
gram Counter.
Example: Jump Absolute Long
JMP 03625
Reg/
Memory
PCU
Contents
Before
Contents
After
Jump Relative (JP)
Jump Absolute (JMP)
42 Hex
36 Hex
36 Hex
25 Hex
Jump Absolute Long (JMPL)
Jump Indirect (JID)
PCL
Jump to Subroutine (JSR)
Jump Indirect. In this 1-byte instruction, the lower byte of
the jump address is obtained from a table stored in program
memory, with the Accumulator serving as the low order byte
of a pointer into program memory. For purposes of access-
ing program memory, the contents of the Accumulator are
written to PCL (temporarily). The data pointed to by the
Program Counter (PCH/PCL) is loaded into PCL, while PCH
remains unchanged.
Jump to Subroutine Long (JSRL)
Jump to Boot ROM Subroutine (JSRB)
Return from Subroutine (RET)
Return from Subroutine and Skip (RETSK)
Return from Interrupt (RETI)
Software Trap Interrupt (INTR)
Vector Interrupt Select (VIS)
Example: Jump Indirect
JID
19.4.3 Load and Exchange Instructions
Reg/
Memory
PCU
Contents
Before
01 Hex
C4 Hex
26 Hex
Contents
After
The load and exchange instructions write byte values in
registers or memory. The addressing mode determines the
source of the data.
01 Hex
32 Hex
26 Hex
Load (LD)
PCL
Load Accumulator Indirect (LAID)
Exchange (X)
Accumulator
Memory
Location
32 Hex
32 Hex
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62
19.0 Instruction Set (Continued)
19.4.4 Logical Instructions
Registers
A
8-Bit Accumulator Register
8-Bit Address Register
B
The logical instructions perform the operations AND, OR,
and XOR (Exclusive OR). Other logical operations can be
performed by combining these basic operations. For ex-
ample, complementing is accomplished by exclusive-ORing
the Accumulator with FF Hex.
X
8-Bit Address Register
S
8-Bit Segment Register
SP
PC
PU
PL
C
8-Bit Stack Pointer Register
15-Bit Program Counter Register
Upper 7 Bits of PC
Logical AND (AND)
Logical OR (OR)
Lower 8 Bits of PC
Exclusive OR (XOR)
1 Bit of PSW Register for Carry
1 Bit of PSW Register for Half Carry
1 Bit of PSW Register for Global Interrupt
Enable
19.4.5 Accumulator Bit Manipulation Instructions
HC
GIE
The Accumulator bit manipulation instructions allow the user
to shift the Accumulator bits and to swap its two nibbles.
Rotate Right Through Carry (RRC)
Rotate Left Through Carry (RLC)
Swap Nibbles of Accumulator (SWAP)
VU
VL
Interrupt Vector Upper Byte
Interrupt Vector Lower Byte
Symbols
19.4.6 Stack Control Instructions
Push Data onto Stack (PUSH)
Pop Data off of Stack (POP)
[B]
Memory Indirectly Addressed by B Register
Memory Indirectly Addressed by X Register
Direct Addressed Memory
Direct Addressed Memory or [B]
Direct Addressed Memory or [B] or
Immediate Data
[X]
MD
19.4.7 Memory Bit Manipulation Instructions
Mem
Meml
The memory bit manipulation instructions allow the user to
set and reset individual bits in memory.
Set Bit (SBIT)
Imm
Reg
8-Bit Immediate Data
Reset Bit (RBIT)
Register Memory: Addresses F0 to FF
(Includes B, X and SP)
Reset Pending Bit (RPND)
Bit
←
↔
Bit Number (0 to 7)
19.4.8 Conditional Instructions
Loaded with
The conditional instruction test a condition. If the condition is
true, the next instruction is executed in the normal manner; if
the condition is false, the next instruction is skipped.
Exchanged with
If Equal (IFEQ)
If Not Equal (IFNE)
If Greater Than (IFGT)
If Carry (IFC)
If Not Carry (IFNC)
If Bit (IFBIT)
If B Pointer Not Equal (IFBNE)
And Skip if Zero (ANDSZ)
Decrement Register and Skip if Zero (DRSZ)
19.4.9 No-Operation Instruction
The no-operation instruction does nothing, except to occupy
space in the program memory and time in execution.
No-Operation (NOP)
Note: The VIS is a special case of the Indirect Transfer of
Control addressing mode, where the double byte vector
associated with the interrupt is transferred from adjacent
addresses in the program memory into the program counter
(PC) in order to jump to the associated interrupt service
routine.
19.5 REGISTER AND SYMBOL DEFINITION
The following abbreviations represent the nomenclature
used in the instruction description and the COP8 cross-
assembler.
63
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19.0 Instruction Set (Continued)
19.6 INSTRUCTION SET SUMMARY
←
←
ADD
ADC
A,Meml
A,Meml
ADD
A
A
A + Meml
A + Meml + C, C Carry,
←
ADD with Carry
←
HC Half Carry
← ←
A − MemI + C, C Carry,
SUBC
A,Meml
Subtract with Carry
A
←
HC Half Carry
←
AND
A,Meml
Logical AND
A
A and Meml
Skip next if (A and Imm) = 0
ANDSZ A,Imm
Logical AND Immed., Skip if Zero
Logical OR
←
←
OR
A,Meml
A,Meml
MD,Imm
A,Meml
A,Meml
A,Meml
#
A
A
A or Meml
XOR
IFEQ
IFEQ
IFNE
IFGT
IFBNE
DRSZ
SBIT
RBIT
IFBIT
RPND
X
Logical EXclusive OR
IF EQual
A xor Meml
Compare MD and Imm, Do next if MD = Imm
Compare A and Meml, Do next if A = Meml
IF EQual
≠
Compare A and Meml, Do next if A Meml
>
Compare A and Meml, Do next if A Meml
≠
Do next if lower 4 bits of B Imm
IF Not Equal
IF Greater Than
If B Not Equal
←
Reg
Decrement Reg., Skip if Zero
Set BIT
Reg Reg − 1, Skip if Reg = 0
#,Mem
#,Mem
#,Mem
1 to bit, Mem (bit = 0 to 7 immediate)
0 to bit, Mem
Reset BIT
IF BIT
If bit #,A or Mem is true do next instruction
Reset Software Interrupt Pending Flag
Reset PeNDing Flag
EXchange A with Memory
EXchange A with Memory [X]
LoaD A with Memory
LoaD A with Memory [X]
LoaD B with Immed.
LoaD Memory Immed.
LoaD Register Memory Immed.
EXchange A with Memory [B]
EXchange A with Memory [X]
LoaD A with Memory [B]
LoaD A with Memory [X]
LoaD Memory [B] Immed.
CLeaR A
↔
↔
←
←
←
A,Mem
A,[X]
A
A
A
A
B
Mem
[X]
X
LD
A,Meml
A,[X]
Meml
[X]
LD
LD
B,Imm
Mem,Imm
Reg,Imm
A, [B ]
A, [X ]
A, [B ]
A, [X ]
[B ],Imm
A
Imm
←
Mem Imm
LD
←
Reg Imm
↔
↔
←
←
LD
←
[B], (B B 1)
X
A
A
A
A
←
[X], (X X 1)
X
←
[B], (B B 1)
LD
←
[X], (X X 1)
LD
← ←
[B] Imm, (B B 1)
LD
←
A
←
A
←
A
←
A
←
A
→
C
←
C
CLR
INC
DEC
LAID
DCOR
RRC
RLC
SWAP
SC
0
A
INCrement A
A + 1
A
DECrement A
A − 1
Load A InDirect from ROM
Decimal CORrect A
Rotate A Right thru C
Rotate A Left thru C
SWAP nibbles of A
Set C
ROM (PU,A)
A
A
A
A
BCD correction of A (follows ADC, SUBC)
→
←
→
←
→
A0 C
A7
A7
…
…
←
←
A0 C, HC A0
↔
A7…A4 A3…A0
←
←
←
←
C
C
1, HC
0, HC
1
0
RC
Reset C
IFC
IF C
IF C is true, do next instruction
IFNC
POP
PUSH
VIS
IF Not C
If C is not true, do next instruction
← ←
SP SP + 1, A [SP]
A
A
POP the stack into A
PUSH A onto the stack
Vector to Interrupt Service Routine
Jump absolute Long
Jump absolute
←
←
[SP] A, SP SP − 1
←
←
PU [VU], PL [VL]
←
PC ii (ii = 15 bits, 0 to 32k)
JMPL
JMP
JP
Addr.
Addr.
Disp.
←
PC9…0 i (i = 12 bits)
←
PC PC + r (r is −31 to +32, except 1)
Jump relative short
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64
19.0 Instruction Set (Continued)
← ← ←
[SP] PL, [SP−1] PU,SP−2, PC ii
JSRL
JSR
Addr.
Addr.
Addr
Jump SubRoutine Long
Jump SubRoutine
←
←
←
[SP] PL, [SP−1] PU,SP−2, PC9…0 i
← ←
[SP] PL, [SP−1] PU,SP−2,
JSRB
Jump SubRoutine Boot ROM
←
←
PL Addr,PU 00, switch to flash
←
PL ROM (PU,A)
JID
Jump InDirect
← ←
SP + 2, PL [SP], PU [SP−1]
RET
RETurn from subroutine
RETurn and SKip
←
←
RETSK
SP + 2, PL [SP],PU [SP−1],
skip next instruction
←
←
←
RETI
INTR
NOP
RETurn from Interrupt
Generate an Interrupt
No OPeration
SP + 2, PL [SP],PU [SP−1],GIE 1
←
←
←
[SP] PL, [SP−1] PU, SP−2, PC 0FF
←
PC PC + 1
19.7 INSTRUCTION EXECUTION TIME
Instructions Using A & C
Most instructions are single byte (with immediate addressing
mode instructions taking two bytes).
CLRA
INCA
DECA
LAID
1/1
1/1
1/1
1/3
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/3
1/3
2/2
Most single byte instructions take one cycle time to execute.
Skipped instructions require x number of cycles to be
skipped, where x equals the number of bytes in the skipped
instruction opcode.
DCORA
RRCA
RLCA
SWAPA
SC
See the BYTES and CYCLES per INSTRUCTION table for
details.
Bytes and Cycles per Instruction
The following table shows the number of bytes and cycles for
each instruction in the format of byte/cycle.
RC
Arithmetic and Logic Instructions
IFC
[B]
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
1/1
Direct
3/4
Immed.
2/2
IFNC
ADD
ADC
SUBC
AND
OR
PUSHA
POPA
ANDSZ
3/4
2/2
3/4
2/2
3/4
2/2
Transfer of Control Instructions
3/4
2/2
XOR
IFEQ
IFGT
IFBNE
DRSZ
SBIT
RBIT
IFBIT
3/4
2/2
JMPL
JMP
JP
3/4
2/3
1/3
3/5
2/5
2/5
1/3
1/5
1/5
1/5
1/5
1/7
1/1
3/4
2/2
3/4
2/2
JSRL
JSR
1/3
3/4
3/4
3/4
1/1
1/1
1/1
JSRB
JID
VIS
RET
RETSK
RETI
INTR
NOP
RPND
1/1
65
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19.0 Instruction Set (Continued)
Memory Transfer Instructions
Register Indirect
Auto Incr. & Decr.
[B+, B−] [X+, X−]
1/2 1/3
1/3
Register
Indirect
Direct Immed.
[B]
1/1
1/1
[X]
1/3
1/3
X A, (Note 19)
LD A, (Note 19)
LD B,Imm
2/3
2/3
2/2
1/1
2/2
1/2
<
(If B 16)
>
(If B 15)
LD B,Imm
LD Mem,Imm
LD Reg,Imm
IFEQ MD,Imm
2/2
3/3
2/3
3/3
2/2
>
Memory location addressed by B or X or directly.
Note 19:
=
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66
N i b b l e L o w e r
67
www.national.com
20.0 Development Support
20.1 TOOLS ORDERING NUMBERS FOR THE COP8 FLASH FAMILY DEVICES
This section provides specific tools ordering information for the devices in this datasheet, followed by a summary of the tools and
development kits available at print time. Up-to-date information, device selection guides, demos, updates, and purchase
information can be obtained at our web site at: www.national.com/cop8.
Unless otherwise noted, tools can be purchased for worldwide delivery from National’s e-store: http://www.national.com/
store/
Tool
Order Number
Cost*
Free
Notes/Includes
Evaluation Software and Reference Designs
Software and
Utilities
Web Downloads:
Assembler/ Linker/ Simulators/ Library Manager/
Compiler Demos/ Flash ISP and NiceMon Debugger
Utilities/ Example Code/ etc.
www.national.com/cop8
(Flash Emulator support requires licensed COP8-NSDEV
CD-ROM).
Hardware
COP8-REF-FL1
COP8-REF-AM
VL
VL
For COP8Flash Sx/Cx - Demo Board and Software;
44PLCC Socket; Stand-alone, or use as development target
board with Flash ISP and/or COP8Flash Emulator. Does not
include COP8 development software.
Reference Designs
For COP8Flash Ax - Demo Board and Software; 28DIP
Socket. Stand alone, or use as development target board
with Flash ISP and/or COP8Flash Emulator. Does not
include COP8 development software.
Starter Kits and Hardware Target Boards
Starter
COP8-SKFLASH-01
VL
VL
Supports COP8Sx/Cx/Ax - Target board with 68PLCC
COP8CDR9, 44PLCC and 28DIP sockets, LEDs, Test
Points, and Breadboard Area. Development CD, ISP Cable,
Debug Software and Source Code. No p/s. Also supports
COP8Flash Emulators and Kanda ISP Tool.
Development Kits
COP8-REF-FL1 or -AM
COP8Flash Hardware Reference Design boards can also be
used as Development Target boards, with ISP and Emulator
onboard connectors.
Software Development Languages, and Integrated Development Environments
National’s WCOP8 COP8-NSDEV
IDE and Assembler
on CD
$3
Fully Licensed IDE with Assembler and
Emulator/Debugger Support. Assembler/ Linker/ Simulator/
Utilities/ Documentation. Updates from web. Included with
SKFlash, COP8 Emulators, COP8-PM.
COP8 Library
www.kkd.dk/libman.htm
Eval
Free
The ultimate information source for COP8 developers -
Integrates with WCOP8 IDE. Organize and manage code,
notes, datasheets, etc.
Manager from KKD
WEBENCH Online www.national.com
Online Graphical IDE, featuring UNIS Processor Expert(
Code Development Tool with Simulator - Develop
applications, simulate and debug, download working code.
Online project manager.
Graphical
/webench
Application Builder
With Unis
Processor Expert
COP8-SW-PE2
L
Graphical IDE and Code Development Tool with
Simulator - Stand-alone, enhanced PC version of our
WEBENCH tools on CD.
Byte Craft C
Compiler
COP8-SW-COP8C
COP8-SW-COP8CW
COP8-SW-EWCOP8
EWCOP8-BL
M
DOS/16bit Version - No IDE.
H
Win 32 Version with IDE.
IAR Embedded
Workbench Tool
Set.
H
Complete tool set, with COP8 Emulator/Debugger support.
Baseline version - Purchase from IAR only.
Assembler only; No COP8 Emulator/Debugger support.
M
Assembler-Only Version
Free
Hardware Emulation and Debug Tools
www.national.com
68
20.0 Development Support (Continued)
Hardware
Emulators
COP8-EMFlash-00
COP8-DMFlash-00
COP8-IMFlash-00
L
Includes 110v/220v p/s, target cable with 2x7 connector, 68
pin COP8CDR9 Null Target, manuals and software on CD.
- COP8AME/ANE9 uses optional 28 pin Null Target
(COP8-EMFA-28N).
M
H
- Add PLCC Target Package Adapter if needed.
68 pin PLCC COP8CDR9; Included in COP8-EM/DM/IM
Flash.
Emulator Null
Target
COP8-EMFA-68N
COP8-EMFA-28N
VL
VL
28pin DIP COP8AME9; Must order seperately.
44 pin PLCC target package adapter. (Use instead of 2x7
emulator header)
Emulator Target
COP8-EMFA-44P
COP8-EMFA-68P
COP8-SW-NMON
VL
Package Adapters
VL
68 pin PLCC target package adapter. (Use instead of 2x7
emulator header)
NiceMon Debug
Monitor Utility
Free
Download code and Monitor S/W for single-step debugging
via Microwire. Includes PC control/debugger software and
monitor program.
Development and Production Programming Tools
Programming
Adapters
COP8-PGMA-28DF1
COP8-PGMA-28SF1
COP8-PGMA-44PF1
COP8-PGMA-44CSF
COP8-PGMA-48TF1
COP8-PGMA-68PF1
COP8-PGMA-56TF1
COP8 USB ISP
L
L
L
L
L
L
L
L
For programming 28DIP COP8AME only.
For programming 28SOIC COP8AME only.
For programming all 44PLCC COP8FLASH.
For programming all 44LLP COP8FLASH.
For programming all 48TSSOP COP8 FLASH.
For programming all 68PLCC COP8FLASH
For programming all 56TSSOP COP8FLASH.
USB connected Dongle, with target cable and Control
Software; Updateable from the web; Purchase from
www.kanda.com
(For any
programmer
supporting flash
adapter base
pinout)
KANDA’s Flash
ISP Programmer
www.kanda.com
Development
Devices
COP8CBR9/CCR9/CDR9
COPCBE9/CCE9
COP8SBR/SCR9/SDR9
COP8SBE/SCE
Free
All packages. Obtain samples from: www.national.com
COP8AME9
<
*Cost: Free; VL= $100; L=$100-$300; M=$300-$1k; H=$1k-$3k; VH=$3k-$5k
69
www.national.com
20.0 Development Support (Continued)
20.2 COP8 TOOLS OVERVIEW
COP8 Evaluation Software and Reference Designs -
Software and Hardware for: Evaluation of COP8 Development Environments; Learning about COP8 Architecture and
Features; Demonstrating Application Specific Capabilities.
Product
WCOP8 IDE and
Software
Description
Source
Software Evaluation downloads for Windows. Includes WCOP8 IDE evaluation
version, Full COP8 Assembler/Linker, COP8-SIM Instruction Level Simulator or Unis
Simulator, Byte Craft COP8C Compiler Demo, IAR Embedded Workbench
(Assembler version), Manuals, Applications Software, and other COP8 technical
information.
www.cop8.com
FREE Download
Downloads
COP8 Hardware
Reference
Reference Designs for COP8 Families. Realtime hardware environments with a
variety of functions for demonstrating the various capabilities and features of specific
COP8 device families. Run Windows demo reference software, and exercise
specific device capabilities. Also can be used as a realtime target board for code
development, with our flash development tools.
NSC Distributor,
or Order from:
www.cop8.com
Designs
(Add our COP8Flash Emulator, or our COP8-NSDEV CD with your ISP cable for a
complete low-cost development system.)
COP8 Starter Kits and Hardware Target Solutions -
Hardware Kits for: In-depth Evaluation and Testing of COP8 capabilities; Developing and Testing Code; Implementing
Target Design.
Product
COP8 Flash
Starter Kits
Description
Source
Flash Starter Kit - A complete Code Development Tool for COP8Flash Families. A
Windows IDE with Assembler, Simulator, and Debug Monitor (does not COP8TAx
devices), combined with a simple realtime target environment. Quickly design and
simulate your code, then download to the target COP8flash device for execution and
simple debugging. Includes a library of software routines, and source code. No
power supply.
NSC Distributor,
or Order from:
www.cop8.com
(Add a COP8-EMFlash Emulator for advanced emulation and debugging)
Preconfigured realtime hardware environments with a variety of onboard I/O and
display functions. Modify the reference software, or develop your own code. Boards
support our COP8 ISP Utility, NiceMon Flash Debug Monitor, and our COP8Flash
Emulators.
COP8 Hardware
Reference
NSC Distributor,
or Order from:
www.cop8.com
Designs
COP8 Software Development Languages and Integrated Environments -
Integrated Software for: Project Management; Code Development; Simulation and Debug.
Description
Product
WCOP8 IDE
from National on
CD-ROM
Source
National’s COP8 Software Development package for Windows on CD. Fully licensed
versions of our WCOP8 IDE and Emulator Debugger, with Assembler/ Linker/
Simulators/ Library Manager/ Compiler Demos/ Flash ISP and NiceMon Debugger
Utilities/ Example Code/ etc. Includes all COP8 datasheets and documentation.
Included with most tools from National.
NSC Distributor,
or Order from:
www.cop8.com
Unis Processor
Expert
Processor Expert( from Unis Corporation - COP8 Code Generation and Simulation
tool with Graphical and Traditional user interfaces. Automatically generates
customized source code "Beans" (modules) containing working code for all on-chip
features and peripherals, then integrates them into a fully functional application code
design, with all documentation.
Unis, or Order
from:
www.cop8.com
Byte Craft
ByteCraft COP8C- C Cross-Compiler and Code Development System. Includes
BCLIDE (Integrated Development Environment) for Win32, editor, optimizing C
Cross-Compiler, macro cross assembler, BC-Linker, and MetaLinktools support.
(DOS/SUN versions available; Compiler is linkable under WCOP8 IDE)
IAR EWCOP8 - ANSI C-Compiler and Embedded Workbench. A fully integrated
Win32 IDE, ANSI C-Compiler, macro assembler, editor, linker, librarian, and C-Spy
high-level simulator/debugger. (EWCOP8-M version includes COP8Flash Emulator
support) (EWCOP8-BL version is limited to 4k code limit; no FP).
ByteCraft
COP8C Compiler
Distributor,
or Order from:
www.cop8.com
IAR Distributor,
or Order from:
www.cop8.com
IAR Embedded
Workbench
www.national.com
70
20.0 Development Support (Continued)
COP8 Hardware Emulation/Debug Tools -
Hardware Tools for: Real-time Emulation; Target Hardware Debug; Target Design Test.
Description
Product
COP8Flash
Source
COP8 In-Circuit Emulator for Flash Families. Windows based development and
real-time in-circuit emulation tool, with trace (EM=None; DM/IM=32k), s/w
breakpoints (DM=16, EM/IM=32K), source/symbolic debugger, and device
programming. Includes COP8-NDEV CD, 68pin Null Target, emulation cable with
2x7 connector, and power supply.
NSC Distributor,
or Order from:
www.cop8.com
Emulators -
COP8-EMFlash
COP8-DMFlash
COP8-IMFlash
NiceMon Debug
Monitor Utility
A simple, single-step debug monitor with one breadpoint. MICROWIRE interface.
Download from:
www.cop8.com
Development and Production Programming Tools -
Programmers for: Design Development; Hardware Test; Pre-Production; Full Production.
Description
Product
COP8 Flash
Emulators
Source
COP8 Flash Emulators include in-circuit device programming capability during
development.
NSC Distributor, or
Order from:
www.cop8.com
Download from:
www.cop8.com
NiceMon
National’s software Utilities "KANDAFlash" and "NiceMon" provide development
In-System-Programming for our Flash Starter Kit, our Prototype Development
Board, or any other target board with appropriate connectors.
Debugger,
KANDAFlash
KANDA
The COP8-ISP programmer from KANDA is available for engineering, and small
volume production use. PC parallel or serial interface.
www.kanda.com
COP8-ISP
SofTec Micro
inDart COP8
COP8
The inDart COP8 programmer from KANDA is available for engineering and
small volume production use. PC serial interface only.
www.softecmicro.com
COP8-PM Development Programming Module. Windows programming tool for
COP8 OTP and Flash Families. Includes on-board 40 DIP programming socket,
control software, RS232 cable, and power supply. (Requires optional
COP8-PGMA programming adapters for COP8FLASH devices)
A variety of third-party programmers and automatic handling equipment are
approved for non-ISP engineering and production use.
NSC Distributor, or
Order from web.
Programming
Module
Third-Party
Programmers
Factory
Various Vendors
Factory programming available for high-volume requirements.
National
Programming
Representative
20.3 WHERE TO GET TOOLS
Tools can be ordered directly from National, National’s e-store (Worldwide delivery: http://www.national.com/store/) , a National
Distributor, or from the tool vendor. Go to the vendor’s web site for current listings of distributors.
Vendor
Home Office
421 King Street North
Waterloo, Ontario
Canada N2J 4E4
Tel: 1-(519) 888-6911
Fax: (519) 746-6751
PO Box 23051
Electronic Sites
www.bytecraft.com
Other Main Offices
Byte Craft Limited
Distributors Worldwide
@
info bytecraft.com
IAR Systems AB
www.iar.se
USA:: San Francisco
Tel: +1-415-765-5500
Fax: +1-415-765-5503
UK: London
@
info iar.se
S-750 23 Uppsala
Sweden
@
info iar.com
@
info iarsys.co.uk
Tel: +46 18 16 78 00
Fax +46 18 16 78 38
@
info iar.de
Tel: +44 171 924 33 34
Fax: +44 171 924 53 41
Germany: Munich
Tel: +49 89 470 6022
Fax: +49 89 470 956
71
www.national.com
20.0 Development Support (Continued)
Vendor
Embedded Results
LTD.
Home Office
P.O. Box 200
Electronic Sites
www.kanda.com
@
sales kanda.co
Other Main Offices
USA:
Tel/Fax: 800-510-3609
Aberystwyth,
@
SY23 2WD, UK
info ucpros.com
Tel/Fax: +44 (0)8707 446 807
Kaergaardsvej 42 DK-8355
Solbjerg Denmark
Fax: +45-8692-8500
2900 Semiconductor Dr.
Santa Clara, CA 95051
USA
www.ucpros.com
@
K and K
www.kkd.dk kkd kkd.dk
Development ApS
National
www.national.com/cop8
Europe:
@
Semiconductor
support nsc.com
Tel: 49(0) 180 530 8585
Fax: 49(0) 180 530 8586
Hong Kong:
@
europe.support nsc.com
Tel: 1-800-272-9959
Fax: 1-800-737-7018
Distributors Worldwide
Germany:
@
SofTec Microsystems Via Roma, 1
33082 Azzano Decimo (PN)
info softecmicro.com
www.softecmicro.com
@
support softecmicro.com
Tel.:+49 (0) 8761 63705
France:
Italy
Tel: +39 0434 640113
Fax: +39 0434 631598
Tel: +33 (0) 562 072 954
UK:
Tel: +44 (0) 1970 621033
The following companies have approved COP8 programmers in a variety of configurations. Contact your vendor’s local office
or distributor and request a COP8FLASH update. You can link to their web sites and get the latest listing of approved
programmers at: www.national.com/cop8.
Advantech; BP Microsystems; Data I/O; Dataman; Hi-Lo Systems; KANDA, Lloyd Research; MQP; Needhams; Phyton; SofTec
Microsystems; System General; and Tribal Microsystems.
21.0 Revision History
Date
Section
Summary of Changes
October 2001
January 2002
Initial Release.
Features
Added temperature range 9, eliminated temperature range 8.
Added Figure.
Forced Execution from
Boot ROM
April 2002
Pin Descriptions
Timers
Caution on GND connection on LLP package.
Clearification on high speed PWM Timer use.
Development Support
Updated with the latest support information.
February 2004 Pin Descriptions
Clarification of the functions of L4 for T2 PWM Output.
Addition of caution regarding rising edge on RESET with low VCC
Reset
.
General
Removed references to COP8CDE9, COP8SDE9 and COP8ANE9 whic are
being placed on Lifetime Buy Status
Electrical Specifications
Changed maximum clock specification for COP8SBE to 3.33MHz
Update of various supply current specifications
Removed references to Brownout disabled devices
Incorporated High Speed Timer/Port L interaction description from User
Information Sheet
RESET
Timers
USART
Incorporated description of device lockup after Line Break
Update to latest tools availability
Development Tools
www.national.com
72
22.0 Physical Dimensions inches (millimeters) unless otherwise noted
LLP Package (LQA)
Order Number COP8SBE9HLQ7, COP8SCE9HLQ7 or COP8SCE9HLQ9
NS Package Number LQA44A
TSSOP Package (MTD)
Order Number COP8SBE9IMT7, COP8SCE9IMT7 or COP8SCE9IMT9
NS Package Number MTD48
73
www.national.com
22.0 Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
Plastic Leaded Chip Carrier (VA)
Order Number COP8SBE9HVA7, COP8SCE9HVA7 or COP8SCE9HVA9
NS Package Number V44A
LIFE SUPPORT POLICY
NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL
COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are devices or
systems which, (a) are intended for surgical implant
into the body, or (b) support or sustain life, and
whose failure to perform when properly used in
accordance with instructions for use provided in the
labeling, can be reasonably expected to result in a
significant injury to the user.
2. A critical component is any component of a life
support device or system whose failure to perform
can be reasonably expected to cause the failure of
the life support device or system, or to affect its
safety or effectiveness.
BANNED SUBSTANCE COMPLIANCE
National Semiconductor certifies that the products and packing materials meet the provisions of the Customer Products
Stewardship Specification (CSP-9-111C2) and the Banned Substances and Materials of Interest Specification
(CSP-9-111S2) and contain no ‘‘Banned Substances’’ as defined in CSP-9-111S2.
National Semiconductor
Americas Customer
Support Center
National Semiconductor
Europe Customer Support Center
Fax: +49 (0) 180-530 85 86
National Semiconductor
Asia Pacific Customer
Support Center
National Semiconductor
Japan Customer Support Center
Fax: 81-3-5639-7507
Email: new.feedback@nsc.com
Tel: 1-800-272-9959
Email: europe.support@nsc.com
Deutsch Tel: +49 (0) 69 9508 6208
English Tel: +44 (0) 870 24 0 2171
Français Tel: +33 (0) 1 41 91 8790
Email: ap.support@nsc.com
Email: jpn.feedback@nsc.com
Tel: 81-3-5639-7560
www.national.com
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.
相关型号：
COP8SBR9HLQ8
8-Bit CMOS Flash Based Microcontroller with 32k Memory, Virtual EEPROM and Brownout
NSC
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