USER'S MANUAL
µPD75402A
4-BIT SINGLE-CHIP MICROCOMPUTER
µPD75402A
µPD75P402
Document No. IEU1270C
(O. D. No. IEU-644D)
Date Published March 1994 P
Printed in Japan
© NEC Corporation 1989
Major Revisions in This Version
Section
P.117
P.179 to 181
Description
Amendment: Fig. 5-52 “Data Transmission from Slave Device
to Master Device”
Change: Appendix B “Development Tools”
The mark ★ shows main revised points.
PREFACE
USER
This manual is intended for user engineers who wish to understand the µPD75402A’s, 75P402’s functions and
design an application system using them.
OBJECTIVE
The objective of this manual is for the user to understand the µPD75402A’s, 75P402’s hardware functions shown
below.
COMPOSITION
This manual is composed roughly of the following contents.
• General description
• Pin functions
• Internal block functions
• Interrupt
• Other internal peripheral functions
• Instruction functions
READING
The reader of this manual must have general knowledge of electricity, logic circuitry and microcomputers.
• Use as the µPD75P402 manual
→This manual describes the µPD75402A as the representative model unless there are particular differences in
functions. If using it as the µPD75P402 manual, the µPD75402A should be read as the µPD75P402.
• Checking an instruction function with a known mnemonic
→Appendix D. “Instructions Index (in Alphabetical Order)” should be used.
• Checking an instruction with an unknown mnemonic but with a roughly known function
→Check the instruction’s mnemonic in 9.2 “Instruction Set and Its Operation” and then check the function in 9.4
“Instruction Functions and Application”.
• Roughly understanding the µPD75402A’s, 75P402’s functions
→Follow the contents.
LEGEND
Data notation weight
Notation of active low
Memory map address
*
:
:
:
:
:
:
:
High-order digit on the left, low-order digit on the right
××× (line over pin, signal name)
Upper__low order, lower__high order
Explanation of * in text
Note
Content to be read carefully
Supplementary explanation of text
Binary ... ×××× or ××××B
Remarks
Numeric notation
Decimal ... ××××
Hexadecimal ... ××××H
Related Documentation
Device Related Documents
Document Name
Document Number
IEU-644
User's Manual
Instruction Application Table
Application Note
IEM-5504
IEA-638
75X Series Selection Guide
IF-151
Development Tool Related Documents
Document Name
Document Number
EEU-846
IE-75000-R/IE-75001-R User's Manual
IE-75000-R-EM User's Manual
EP-75402C-R User's Manual
EP-75402GB-R User's Manual
PG-1500 User's Manual
EEU-673
EEU-701
EEU-702
EEU-651
Operation
Language
RA75X Assembler Package l
User's Manua
EEU-731
EEU-730
PG-1500 Controller User's Manual
EEU-704
Other Related Documents
Document Name
Document Number
IEI –635
Package Manual
Surface Mount Technology Manual
IEI –616
Quality Grade on NEC Semiconductor Devices
NEC Semiconductor Device Reliability & Quality Control
Electrostatic Discharge (ESD) Test
IEI –620
IEM –5068
MEM –539
MEI –603
Semiconductor Devices Quality Control Guarantee Guide
Microcomputer Related Products Guide. Other Manufacturers
MEI –604
Note The above documents are subject to change without notice.
The latest documents should be used for design purposes, etc.
CONTENTS
CHAPTER 1. GENERAL...............................................................................................................................
1
1.1 OUTLINE OF FUNCTIONS . ..........................................................................................................................
1.2 ORDERING INFORMATION AND QUALITY GRADE..................................................................................
1.3 DIFFERENCES BETWEEN µPD75402A AND µPD75402, 75P402..............................................................
1.4 BLOCK DIAGRAM ..........................................................................................................................................
1.5 PIN CONFIGURATION...................................................................................................................................
2
3
4
5
6
6
8
1.5.1
1.5.2
28-Pin Plastic DIP (600 mil), Shrink DIP (400 mil) .....................................................................
44-Pin Plastic QFP ( ■10 mm) ....................................................................................................
CHAPTER 2. PIN FUNCTIONS .................................................................................................................. 10
2.1 µPD75402A PIN FUNCTION LIST ................................................................................................................ 11
2.1.1
2.1.2
Port Pin List .................................................................................................................................... 11
List of Pins Other than Port Pins ................................................................................................. 12
2.2 NORMAL OPERATING MODE ...................................................................................................................... 13
2.2.1
2.2.2
2.2.3
2.2.4
2.2.5
2.2.6
2.2.7
2.2.8
2.2.9
2.2.10
P00 to P03 (Port 0), P10, P12 (Port 1) ......................................................................................... 13
P20 to P23 (Port 2), P30 to P33 (Port 3), P50 to P53 (Port 5), P60 to P63 (Port 6) ................ 14
SCK, SO/SB0, SI............................................................................................................................. 14
INT0 ................................................................................................................................................. 14
INT2 ................................................................................................................................................. 14
PCL .................................................................................................................................................. 14
X1, X2.............................................................................................................................................. 15
RESET (Reset) ................................................................................................................................ 15
VDD ................................................................................................................................................... 15
VSS ................................................................................................................................................... 15
2.3 PROM MODE.................................................................................................................................................. 16
2.3.1
2.3.2
2.3.3
2.3.4
2.3.5
2.3.6
2.3.7
A0 to A14 (Address) ...................................................................................................................... 16
O0 to O7 (Data) .............................................................................................................................. 16
CE (Chip Enable)............................................................................................................................ 16
OE (Output Enable) ....................................................................................................................... 16
VPP .................................................................................................................................................... 16
VDD ................................................................................................................................................... 16
VSS ................................................................................................................................................... 16
2.4 PIN INPUT/OUTPUT CIRCUITS ................................................................................................................... 17
2.5 UNUSED PIN TREATMENT .......................................................................................................................... 20
2.6 NOTES ON USE OF P00 PIN AND RESET PIN........................................................................................... 20
CHAPTER 3. FEATURES OF ARCHITECTURE AND MEMORY MAP............................................... 21
3.1 DATA MEMORY BANK CONFIGURATION AND ADDRESSING MODES ............................................... 21
3.1.1
3.1.2
Data Memory Bank Configuration .............................................................................................. 21
Data Memory Addressing Modes ............................................................................................... 24
3.2 MEMORY-MAPPED I/O ................................ .............................................................................................. 28
- i -
CHAPTER 4. INTERNAL CPU FUNCTIONS ........................................................................................... 31
4.1 PROGRAM COUNTER (PC)........................................................................................................................... 31
4.2 PROGRAM MEMORY (ROM) . ..................................................................................................................... 32
4.3
DATA MEMORY (RAM) ............................................................................................................................... 33
4.4 GENERAL REGISTER . .................................................................................................................................. 35
4.5 ACCUMULATOR ............................................................................................................................................ 36
4.6 STACK POINTER (SP) ................................................................................................................................... 37
4.7 PROGRAM STATUS WORD (PSW) ............................................................................................................. 39
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS ........................................................................ 41
5.1 DIGITAL INPUT/OUTPUT PORTS ................................................................................................................ 41
5.1.1
5.1.2
5.1.3
5.1.4
5.1.5
5.1.6
Digital Input/Output Port Types, Characteristics and Configuration...................................... 42
Input/Output Mode Setting .......................................................................................................... 46
Digital Input/Output Port Handling Instructions ....................................................................... 47
Digital Input/Output Port Operations.......................................................................................... 49
Internal Pull-Up Resistors ............................................................................................................ 51
Digital Input/Output Port Input/Output Timing ......................................................................... 53
5.2 CLOCK GENERATION CIRCUIT.................................................................................................................... 54
5.2.1
5.2.2
5.2.3
5.2.4
Clock Generation Circuit Configuration ..................................................................................... 54
Clock Generation Circuit Function and Operation .................................................................... 55
CPU Clock Setting ......................................................................................................................... 59
Differences Between µPD75402A and µPD75402 ...................................................................... 61
5.3 CLOCK OUTPUT CIRCUIT............................................................................................................................. 63
5.3.1
5.3.2
5.3.3
5.3.4
Clock Output Circuit Configuration............................................................................................. 63
Clock Output Mode Register (CLOM) ......................................................................................... 64
Clock Output Procedure ............................................................................................................... 65
Example of Remote Control Application.................................................................................... 65
5.4 BASIC INTERVAL TIMER .............................................................................................................................. 66
5.4.1
5.4.2
5.4.3
5.4.4
Basic Interval Timer Configuration ............................................................................................. 66
Basic Interval Timer Mode register (BTM)................................................................................. 67
Basic Interval Timer Operation.................................................................................................... 68
Examples of Basic Interval Timer Applications ........................................................................ 69
5.5 SERIAL INTERFACE ....................................................................................................................................... 70
5.5.1
5.5.2
5.5.3
5.5.4
5.5.5
5.5.6
Serial Interface Functions ............................................................................................................ 70
Serial Interface Configuration ..................................................................................................... 71
Register Functions......................................................................................................................... 74
Operation-Halt Mode .................................................................................................................... 83
3-Wire Serial I/O Mode Operation............................................................................................... 84
SBI Mode Operation ..................................................................................................................... 93
CHAPTER 6. INTERRUPT FUNCTIONS .................................................................................................. 126
6.1 INTERRUPT CONTROL CIRCUIT CONFIGURATION.................................................................................. 126
6.2 INTERRUPT SOURCE TYPES AND VECTOR TABLE ................................................................................. 128
6.3 INTERRUPT CONTROL CIRCUIT HARDWARE ........................................................................................... 129
6.4 INTERRUPT SEQUENCE ............................................................................................................................... 134
- ii -
6.5 MACHINE CYCLES BEFORE INTERRUPT SERVICING .............................................................................. 135
6.6 INTERRUPT APPLICATIONS ........................................................................................................................ 137
CHAPTER 7. STANDBY FUNCTION ....................................................................................................... 141
7.1 STANDBY MODE SETTING AND OPERATION STATES .......................................................................... 142
7.2 STANDBY MODE RESET .............................................................................................................................. 143
7.3 OPERATION AFTER STANDBY MODE RESET ........................................................................................... 145
7.4 STANDBY MODE APPLICATION ................................................................................................................. 145
CHAPTER 8. RESET FUNCTION ............................................................................................................... 146
CHAPTER 9. INSTRUCTION SET ............................................................................................................. 148
9.1 SPECIAL INSTRUCTION ............................................................................................................................... 149
9.1.1
9.1.2
9.1.3
9.1.4
Bit Operation Instructions ............................................................................................................ 149
Stack Instructions .......................................................................................................................... 149
Base Correction Instructions........................................................................................................ 150
Skip Instruction and Number of Machine Cycles Required by Skip ...................................... 150
9.2 INSTRUCTION SET AND ITS OPERATION ................................................................................................. 151
9.3 OPERATION CODE OF EACH INSTRUCTION............................................................................................. 156
9.4 INSTRUCTION FUNCTIONS AND APPLICATION ...................................................................................... 159
9.4.1
9.4.2
9.4.3
9.4.4
9.4.5
9.4.6
9.4.7
9.4.8
9.4.9
9.4.10
9.4.11
9.4.12
9.4.13
Move Instructions.......................................................................................................................... 159
Table Reference Instructions ....................................................................................................... 162
Arithmetic and Logic Instructions ............................................................................................... 163
Accumulator Operation Instructions .......................................................................................... 165
Increment/Decrement Instructions.............................................................................................. 166
Compare Instructions ................................................................................................................... 167
Carry Flag Operation Instructions ............................................................................................... 168
Bit Manipulation Instructions ...................................................................................................... 169
Branch Instructions ....................................................................................................................... 171
Subroutine Stack Control Instructions ....................................................................................... 172
Interrupt Control Instructions ...................................................................................................... 174
Input/Output Instructions ............................................................................................................. 175
CPU Control Instructions .............................................................................................................. 176
APPENDIX A. TABLE OF INSTRUCTION USABLE WITH EVAKIT-75X ONLY .............................. 177
APPENDIX B. DEVELOPMENT TOOLS................................................................................................... 179
APPENDIX C. MASK ROM ORDERING PROCEDURE ......................................................................... 182
APPENDIX D. INSTRUCTION INDEX (ALPHABETIC ORDER)............................................................ 183
APPENDIX E. HARDWARE INDEX (ALPHABETIC ORDER) ................................................................ 184
- iii -
CONTENTS OF FIGURES
Title
Fig. No
Page
3-1
Static RAM Address Updating Method ............................................................................................. 25
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
Program Counter Configuration ......................................................................................................... 31
Program Memory Map ........................................................................................................................ 32
Data Memory Map ............................................................................................................................... 33
General Register Configuration.......................................................................................................... 35
Register Pair Configuration................................................................................................................. 35
Accumulators ........................................................................................................................................ 36
Stack Pointer Configuration ................................................................................................................ 37
Data Saved to Stack Memory ............................................................................................................. 38
Data Restored from Stack Memory ................................................................................................... 38
Program Status Word Configuration ................................................................................................. 39
5-1
Digital Input/Output Port Data Memory Addresses ......................................................................... 41
Configuration of Ports 0 and 1 ........................................................................................................... 43
Configuration of Port 3 . ...................................................................................................................... 44
Configuration of Ports 2 and 6 ........................................................................................................... 45
Configuration of Port 5 ........................................................................................................................ 46
Format of Port Mode Registers .......................................................................................................... 47
Format of Pull-Up Resistor Specification Register .......................................................................... 52
Pull-Up Resistor Incorporation Switching Timing ........................................................................... 52
Digital Input/Output Port Input/Output Timing ................................................................................ 53
Clock Generation Circuit Block Diagram ........................................................................................... 54
Processor Clock Control Register Format ......................................................................................... 56
System Clock Oscillation Circuit External Circuitry......................................................................... 57
Example of Poor Resonator Connection Circuit............................................................................... 57
Use of Variable Minimum Instruction Execution Time Function................................................... 59
Change of Φ after Power-On Reset .................................................................................................... 60
Clock Generation Circuit - Differences between µPD75402A and µPD75402 ............................... 61
µPD75402 Processor Clock Control Register Format....................................................................... 62
Clock Output Circuit Configuration .................................................................................................... 63
Clock Output Mode Register Format ................................................................................................ . 64
Example of Remote Control Application........................................................................................... 65
Basic Interval Timer Configuration .................................................................................................... 66
Basic Interval Timer Mode Register Format ..................................................................................... 67
Example of SBI System Configuration .............................................................................................. 71
Serial Interface Block Diagram ........................................................................................................... 72
Serial Operating Mode Register (CSIM) Format .............................................................................. 75
Serial Bus Interface Control Register (SBIC) Format....................................................................... 78
Configuration Around Shift Register ................................................................................................. 81
Example of 3-Wire Serial I/O System Configuration ....................................................................... 84
3-Wire Serial I/O Mode Timing ........................................................................................................... 88
RELT & CMDT Operation..................................................................................................................... 89
Shift Register (SIO) and Internal Bus Configuration ....................................................................... 90
5-2
5-3
5-4
5-5
5-6
5-7
5-8
5-9
5-10
5-11
5-12
5-13
5-14
5-15
5-16
5-17
5-18
5-19
5-20
5-21
5-22
5-23
5-24
5-25
5-26
5-27
5-28
5-29
5-30
5-31
- iv -
Fig. No.
Title
Page
5-32
5-33
5-34
5-35
5-36
5-37
5-38
5-39
5-40
5-41
5-42
5-43
5-44
5-45
5-46
5-47
5-48
5-49
5-50
5-51
5-52
5-53
5-54
5-55
5-56
5-57
5-58
5-59
5-60
5-61
Example of SBI Serial Bus System Configuration ........................................................................... 93
SBI Transfer Timing ............................................................................................................................. 95
Bus Release Signal ............................................................................................................................... 96
Command Signal .................................................................................................................................. 96
Address .................................................................................................................................................. 97
Slave Selection by Address ................................................................................................................ 97
Command .............................................................................................................................................. 98
Data ........................................................................................................................................................ 98
Acknowledge Signal ............................................................................................................................ 99
Busy Signal & Ready Signal ............................................................................................................. 100
RELT, CMDT, RELD & CMDD Operation (Master) .......................................................................... 106
RELT, CMDT, RELD & CMDD Operation (Slave) ........................................................................... . 106
ACKT Operation .................................................................................................................................. 107
ACKE Operation .................................................................................................................................. 108
ACKD Operation ................................................................................................................................. 109
BSYE Operation .................................................................................................................................. 109
Pin Configuration Diagram ............................................................................................................... 112
Address Transmission from Master Device to Slave Device (WUP = 1) .................................... 114
Command Transmission from Master Device to Slave Device ................................................... 115
Data Transmission from Master Device to Slave Device.............................................................. 116
Data Transmission from Slave Device to Master Device.............................................................. 117
Example of Serial Bus Configuration .............................................................................................. 119
READ Command Transfer Format.................................................................................................... 121
WRITE & END Command Transfer Format ..................................................................................... 121
STOP Command Transfer Format.................................................................................................... 122
STATUS Command Transfer Format............................................................................................... 123
STATUS Command Status Format .................................................................................................. 123
RESET Command Transfer Format .................................................................................................. 124
CHGMST Command Transfer Format ............................................................................................ . 124
Master and Slave Operations after an Error................................................................................... 125
6-1
6-2
6-3
6-4
6-5
6-6
6-7
6-8
Interrupt Control Circuit Block Diagram.......................................................................................... 127
Interrupt Vector Table ........................................................................................................................ 128
Configuration of INT0 and INT2 ....................................................................................................... 130
INT0 Noise Elimination Circuit Input/Output Timing .................................................................... 131
INT2 Input Noise Elimination . ......................................................................................................... 131
Edge Detection Mode Register Format ........................................................................................... 132
IME Format .......................................................................................................................................... 132
Interrupt Servicing Procedure .......................................................................................................... 134
7-1
Standby Mode Reset Operation ....................................................................................................... 144
8-1
8-2
Reset Signal Acceptance ................................................................................................................... 146
Reset at Power-on .............................................................................................................................. 146
- v -
CONTENTS OF TABLES
Title
Table No.
Page
1-1
Differences Between µPD75402A and µPD75402, 75P402 ................................................................. 4
2-1
2-2
2-3
2-4
Port Pin List ........................................................................................................................................... 11
List of Pins Other than Port Pins ........................................................................................................ 12
Port 0’s, 1’s Dual-Function Pins.......................................................................................................... 13
Pin Input/Output Types ........................................................................................................................ 17
3-1
Data Memory Configuration and Address Range
in Each Addressing Mode ................................................................................................................... 22
Addressing Mode List .......................................................................................................................... 23
Applicable Addressing Modes at Peripheral Hardware Operation ............................................... 28
µPD75402A I/O Map ............................................................................................................................. 29
3-2
3-3
3-4
4-1
4-2
Carry Flag Manipulation Instructions ................................................................................................ 39
Interrupt Status Flag Indication Content ........................................................................................... 40
5-1
5-2
5-3
5-4
5-5
5-6
5-7
5-8
Digital Input/Output Port Types and Characteristics ....................................................................... 42
List of Input/Output Pin Handling Instructions................................................................................. 48
Operations with Input/Output Port Handling Instructions .............................................................. 50
Internal Pull-up Resister Specification for Each Port ...................................................................... 51
Maximum Time Required for Change of CPU Clock ....................................................................... 60
Serial Clock Selection and Use (in 3-Wire Serial I/O Mode) .......................................................... 89
Serial Clock Selection and Use (in SBI Mode) ............................................................................... 105
Signals in SBI Mode........................................................................................................................... 110
6-1
6-2
6-3
Interrupt Request Source Types....................................................................................................... 128
Interrupt Request Flag Setting Signal ............................................................................................. 129
IST0 Interrupt Servicing Status ........................................................................................................ 133
7-1
8-1
Standby Mode Operation States ...................................................................................................... 142
State of Hardware after Reset .......................................................................................................... 147
- vi -
CHAPTER 1. GENERAL
The µPD75402A, 75P402 is a CMOS 4-bit single-chip microcomputer adopting the 75X architecture. With its built-
in NEC standard serial bus interface (SBI), it is suitable as a slave microcomputer in a multiprocessor system
configuration using the 75X, 78K series as the host microcomputer.
The µPD75402A has shortened the conventional µPD75402’s minimum instruction execution time to 0.95 µs. The
µPD75P402 is also capable of high-speed processing.
It is possible to reduce the burden on the host microcomputer by using the µPD75402A, 75P402 as the slave
microcomputer by using the µPD75402A, 75P402 as the slave microcomputer for decentralized processing. The
µPD75402A, or 75P402 is most suitable for slave processes for the following devices such as the key input control,
LED, etc. display control, or remote control send/receive control, etc.
• FAX
• PPC
• Printer
• ECR
• VCR
• Remote control commander
The µPD75P402 is a product with the µPD75402A’s built-in mask ROM having been replaced with the one-time
PROM. It is compatible with theµPD75402A except for the program memory and the mask option. The pin connection
at write is the same as in the standard EPROM µPD27C256A and also has the same writing characteristics. Therefore,
it is possible to write directly using the general-purpose PROM writer. The µPD75P402 is suitable for preproduction
at system development and short-run and multiple-device production.
Name
µPD75402A
µPD75P402
Program Memory
1920 × 8 (mask ROM)
Data Memory
64 × 4 (RAM)
64 × 4 (RAM)
1920 × 8 (one-time PROM)
Remarks In this manual, the µPD75402A is described as the representative model unless there are particular
differences in functions. If using it as the µPD75P402 manual, the µPD75402A, should be read as the
µPD75P402.
1
CHAPTER 1. GENERAL
1.1 OUTLINE OF FUNCTIONS
Item
Description
Number of basic
instructions
37
Instruction
execution time
• 0.95 µs, 1.91 µs, 15.3 µs (at 4.19 MHz operation)
selectable between 3 levels
Built-in
memory
Program
memory
1920 × 8 bits (µPD75402A: Mask ROM, µPD75P402: One-time PROM)
64 × 4 bits (RAM)
Data
memory
General register
Accumulators
4 bits × 4, or 8 bits × 2 (memory mapping)
3 accumulators to suit manipulation data length
• Bit accumulator (CY), 4-bit accumulator (A), 8-bit accumulator (XA)
I/O line
Total 22 lines
• CMOS input port
• CMOS input/output port (LED direct drivable 8 lines)
• N-ch open-drain input/ output port (LED direct drivable)
: 6 lines
: 12 lines
: 4 lines
Pull-up resistor
Clock output
• Pull-up resistor built-in control possible by software
• Pull-up resistor built-in control possible by mask option (µPD75402A only) : 4 lines
: 16 lines
• 1.05 MHz, 524 kHz, 65.5 kHz (at 4.19 MHz operation)
• Applicable to remote control output
Timer/Counter
8-bit basic interval timer
• Reference time generation (1.95 ms, 31.3 ms : at 4.19 MHz operation)
• Watchdog timer applicable
Serial interface
• 8 bits
• 2 transfer modes (clock synchronous 3-wire system mode/SBI mode)
Vectored
interrupt
External: 1 line, internal : 2 lines
Test input
External: 1 line
(For details, see CHAPTER 6 “INTERRUPT FUNCTIONS”.)
Standby
STOP mode/HALT mode
Instruction set
• Bit manipulation instruction (set, clear, test, Boolean operation)
• 1-byte relative branch instruction
• 4-bit operation instruction (add, Boolean operation, compare)
• 4, 8-bit data transfer instruction
Package
• 28-pin plastic DIP (600 mil)
• 28-pin plastic shrink DIP (400 mil)
• 44-pin plastic QFP ( ■ 10 mm)
2
CHAPTER 1. GENERAL
1.2 ORDERING INFORMATION AND QUALITY GRADE
(1) Ordering Information
Ordering Code
µPD75402AC-×××
µPD75402ACT-×××
µPD75402AGB-×××-3B4
µPD75P402C
Package
Program Memory
Mask ROM
28-pin plastic DIP
(600 mil)
(400 mil)
( ■10mm)
(600 mil)
(400 mil)
( ■10mm)
28-pin plastic shrink DIP
44-pin plastic QFP
28-pin plastic DIP
One-time PROM
µPD75P402CT
28-pin plastic shrink DIP
44-pin plastic QFP
µPD75P402GB-3B4
×××: ROM code number
(2) Quality Grade
Standard
Please refer to “Quality grade on NEC Semiconductor Devices” (Document number IEI-1209) published by NEC
Corporation to know the specification of quality grade on the devices and its recommended applications.
3
CHAPTER 1. GENERAL
1.3 DIFFERENCES BETWEEN µPD75402A AND µPD75402, 75P402
Table 1-1 shows the differences between the µPD75402A and the µPD75402, 75P402. Otherwise the µPD75402A
and the µPD75402, 75P402 have the same functions and are pin-compatible.
Table 1-1 Differences Between µPD75402A and µPD75402, 75P402
Item
µPD75402A
µPD75402
µPD75P402
ROM configuration
Mask ROM
One-time PROM
Instruction
0.95, 1.91, 15.3 µs
1.91, 15.3 µs*
0.95, 1.91, 15.3 µs
execution time
(at 4.19 MHz operation)
(at 4.19 MHz operation)
(at 4.19 MHz operation)
Port 5’s pull-up resistor
Designatable to be built in by mask option
NC
Not available
1-pin (SDIP)
30-pin (QFP)
Pin
VPP
functions
Supply voltage
Operating
2.7 to 6.0 V
5 V ±10%
–40 to +85°C
–10 to +70°C
temperature range
Package
• 28-pin plastic DIP (600 mil)
• 28-pin plastic shrink DIP (400 mil)
• 44-pin plastic QFP ( ■ 10 mm)
*
The µPD75402A has shortened the µPD75402’s minimum instruction execution time to 0.95 µs.
For details, see 5.2.4 “Differences Between µPD75402A And µPD75402”.
4
4
2
PORT0
PORT1
P00-P03
P10, P12
BASIC
INTERVAL
TIMER
ALU
CY
SP (5)
PROGRAM
COUNTER(11)
INTBT
4
PORT2
PORT3
PORT5
PORT6
P20-P23
P30-P33
P50-P53
P60-P63
SI
SO/SB0
SCK
SERIAL
INTERFACE
ROM (PROM)
PROGRAM
MEMORY
4
4
4
GENERAL REG.
DECODE
AND
INTCSI
CONTROL
RAM
DATA MEMORY
64 x 4 bits
1920 × 8 bits
INT0
INT2
INTERRUPT
CONTROL
fxx/2N
CPU CLOCK
CLOCK
OUTPUT
CONTROL
ø
CLOCK
DIVIDER
CLOCK
GENERATOR
STAND BY
CONTROL
PCL
X1
X2
VDD
VSS RESET
NC
(VPP)
Remarks Parentheses for the µPD75P402.
CHAPTER 1. GENERAL
1.5
PIN CONFIGURATION
1.5.1 28-Pin Plastic Dip (600 mil), Shrink Dip (400 mil)
(1) Normal operating mode
*
VDD
1
2
(VPP) NC
RESET
P00
28
X1
27
26
25
24
23
X2
3
4
5
6
7
8
9
P12/INT2
P10/INT0
P23
P01/SCK
µ
µ
P02/SO/SB0
P03/SI
P22/PCL
P21
P50
P51
P52
P53
P30
P31
P32
22
21
20
19
18
17
16
15
P20
P63
10
11
12
13
14
P62
P61
P60
P33
VSS
P00 to P03 : Port 0
SCK
: Serial clock input/output
: Serial output/input/output
: Serial input
P10, P12
: Port 1
SO/SB0
SI
P20 to P23 : Port 2
P30 to P33 : Port 3
P50 to P53 : Port 5
P60 to P63 : Port 6
PCL
: Clock output
INT0
INT2
X1, X2
RESET
VDD
: External vectored interrupt input
: External test input
: Oscillator pin
: Reset input
: Power supply
VSS
: Ground
VPP
: Externally set to GND potential
: No connection
NC
Remarks Parentheses for the µPD75P402.
*
If using the µPD75P402 and the printed circuit board commonly in the µPD75402A, the NC pin is to be set to the
GND potential.
6
CHAPTER 1. GENERAL
(2) PROM mode
1
2
3
4
VPP
A12
A7
A6
A5
A4
A3
A2
A1
A0
O0
O1
O2
VSS
28
27
26
25
24
23
22
VDD
A14
A13
A8
5
6
7
8
9
µ
A9
A11
OE
A10
CE
21
20
19
18
17
16
15
10
11
12
13
14
O7
O6
O5
O4
O3
A0 to A14
O0 to O7
CE
: Address input
: Data input/output
: Chip enable input
: Output enable input
: Power supply
OE
VDD
VPP
: Program power supply
: Ground
VSS
7
CHAPTER 1. GENERAL
1.5.2 44-Pin Plastic QFP ( ■ 10mm)
(1) Normal operating mode
34
44 43 42 41 40 39 38 37 36 35
1
2
3
4
5
6
7
8
9
P30
P31
P32
NC
P01/SCK
P00
33
32
31
30
RESET
NC (VPP)*
NC
VSS
NC
NC
29
µPD75402AGB-×××-3B4
28
NC
µPD75P402GB-×××-3B4
NC
27
26
25
VDD
P33
P60
P61
NC
X1
10
24
X2
11
23
NC
12 13 14 15 16 17 18 19 20 21 22
Remarks Parentheses for the µPD75P402.
*
If using the µPD75P402 and the printed circuit board commonly in the µPD75402A, the NC pin of the 30-pin
corresponding to the µPD75P402’s VPP is to be set to the GND potential.
8
CHAPTER 1. GENERAL
(2) PROM mode
44 43 42 41 40 39 38 3357 34
36
A6
O0
O1
O2
NC
VSS
NC
NC
O3
O4
O5
NC
1
2
33
A7
32
31
30
3
4
A12
VPP
NC
NC
NC
VDD
A14
5
29
28
27
26
25
24
6
µPD75P402GB-3B4
7
8
9
A13
NC
10
11
23
12 13 14 15 16 17 18 19 20 21 22
9
CHAPTER 2. PIN FUNCTIONS
The µPD75402A operates by the pin functions in the normal operating mode.
For the µPD75P402’s pin functions, the 2 modes of the normal operating mode (µPD75402A mode) and the PROM
mode are available.
The operating mode switches according to the VPP pin level as shown in the table below.
VPP
Operating Mode
Low level (GND potential)
High level (+5 V)
Normal operating mode
PROM read mode
PROM mode
High level (+12.5 V)
PROM write/verify mode
10
CHAPTER 2. PIN FUNCTIONS
2.1 µPD75402A PIN FUNCTION LIST
2.1.1 Port Pin List
Table 2-1 Port Pin List
Functions
Pin Name
Input/Output
Dual-Function Pin
A 4-bit input port (Port 0).
P00
P01
P02
P03
P10
Input
For P01 to P03, it is designatable to build in the pull-up resistor by
software in 3-bit units.
Input/output
Input/output
Input
SCK
SO/SB0
SI
A 2-bit input port (Port 1).
Input
INT0
P10 is built in with the noise eliminator by the sampling clock.
P12 is built in with the noise eliminator by analog delay.
For P12, it is designatable to build in the pull-up resistor by
software.
P12
INT2
A 4-bit input/output port (Port 2).
P20
P21
Input/output
Input/output
It is designatable to input/output in 4-bit units.
It is designatable to build in the pull- up resistor by software in 4-
bit units.
P22
PCL
P23
A programmable 4-bit input/output port (Port 3).
It is designatable to input/output bit-wise.
It is designatable to build in the pull-up resistor by software in 4-
bit units.
P30 to P33
It is possible to drive the LED directly.
A 4-bit N-ch open drain input/output port (Port 5).
It is designatable to input/output in 4-bit units.
It is designatable to build in the pull-up resistor by mask
option bit-wise.
P50 to P53
Input/output
It is possible to drive the LED directly.
A 4-bit input/output port (Port 6).
Input/output
P60 to P63
It is designatable to input/output in 4-bit units.
It is designatable to build in the pull-up resistor by software in
4-bit units.
It is possible to drive the LED directly.
Remarks 1. In the µPD75402A, 8-bit input/output with 2 ports making up a pair is impossible.
2. For the status of each pin at reset, see CHAPTER 8 “RESET FUNCTION”.
11
CHAPTER 2. PIN FUNCTIONS
2.1.2 List of Pins Other Than Port Pins
Table 2-2 List of Pins Other than Port Pins
Functions
Pin Name
INT0
Input/Output
Input
Dual-Function Pin
An edge-detected vectored interrupt request input pin (detected
edge selectable by mode register).
Built in with the noise eliminator by the sampling clock.
An edge detected external test input pin (rising edge detection).
A serial data input pin.
P10
INT2
SI
Input
P12
P03
Input
A serial data output pin.
SO
Input/output
Input/output
Input/output
Input/output
Input
P02/SB0
P01
A serial clock input/output pin.
SCK
SB0
PCL
X1, X2
A serial bus input/output pin.
P02/SO
P22
A clock output pin.
A system clock oscillation crystal/ ceramic resonator connection
pin. If supplying the clock from the exterior, input to X1 and input
the inverted phase to X2.
A system reset input pin. Built in with the noise eliminator by
analog delay.
RESET
Input
A positive power supply pin.
VDD
VSS
A GND potential pin.
No Connection
NC*8
Remarks For the status of each pin at reset, see CHAPTER 8 “RESET FUNCTION”.
*
If using the µPD75P402 and the printed circuit board commonly, the NC pin should be connected directly to VSS.
12
CHAPTER 2. PIN FUNCTIONS
2.2 NORMAL OPERATING MODE
2.2.1 P00 to P03 (Port 0) ..... SCK, SO/SB0, SI Dual-Function Input
P10, P12 (Port 1) ..... INT0, INT2 Dual-Function Input
P00 to P03 are the 4-bit input port: Port 0’s input pins. P10 and P12 are the 2-bit input port: Port 1’s input pins.
Ports 0 and 1 also have the functions of the various control signal pins shown in Table 2-1 in addition to the
functions as input ports. The status of each of Ports 0 and 1 is always inputtable irrespective of the dual-function
pin operation.
Both Ports 0 and 1 have Schmitt-triggered input to prevent malfunction by noise. P10 is built in with the noise
eliminator by the sampling clock and P12 is built in with the noise eliminator by analog delay.
Ports 0 and 1 allow to designate to build in the pull-up resistor respectively in 3-bit units (P01 to P03) and bit-
wise (P12 only). Such designation is made using the pull-up resistor designation register (POGA). Neither P00 or
P10 can be built in with the pull-up resistor.
Any of these pins assumes the input port mode at RESET input.
Table 2-3 Port 0’s, 1’s Dual-Function Pins
Port 0
P00
Dual-Function
Pin Port 1
P10
Dual-Function Pin
INT0
INT2
P01
SCK
SO/SB0
SI
P12
P02
P03
13
CHAPTER 2. PIN FUNCTIONS
2.2.2 P20 to P23 (Port 2) ..... PCL Dual-Function 3-Stae Input/Otput
P30 to P33 (Port 3) ..... 3-State Input/Output
P50 to P53 (Port 5) ..... N-ch Open Drain Middle-Voltage (10 V) Input/Output
P60 to P63 (Port 6) ..... 3-State Input/Output
The 4-bit input/output port with the output latch: Port 2’s, 3’s, 5’s, 6’s 4-bit input/output pins. Port 2 also shares
the programmable clock output (PCL) function with P22 in addition to having the input/output port function. Port
5 has the N-ch open drain middle-voltage (10 V) output.
Port 3 allows to designate input/output bit-wise using the port mode register (PMGA). Ports 2, 5 and 6 allow to
designate input/output in 4-bit units using the port mode register (PMGA, PMGB).
Ports 2, 3 and 6 allow to designate to build in the pull-up resistor by software in 4-bit units. Such designation
is made using the pull-up resistor designation register (POGA).
The µPD75402A’s Port 5 allows to designate to build in the pull-up resistor by mask option bit-wise. The
µPD75P402’s Port 5 cannot be built in with the pull-up resistor. Ports 3, 5 and 6 have large-current output and can
drive the LED directly.
Ports 2, 3 and 6 turn input ports (output high impedance) at RESET input. Port 5 turns high level (if built in with
the pull-up resistor) or high impedance. The content of the output latch turns indeterminate.
2.2.3 SCK, SO/SB0, SI ..... Port 0 Dual-Function 3-State Input/Output
A serial interface input/output pin. It operates according to the serial operating mode register (CSIM) setting.
Each has Schmitt-triggered input.
The serial interface stops at RESET input and each turns into an input port.
2.2.4
INT0 ..... Port 1 Dual-Function Input
An external interrupt request input pin. It is designatable for either of the 3 of rising edge detection, falling edge
detection and rising and falling edge detection using the external interrupt mode register (IM0).
INT0 has Schmitt-triggered input and is built in with the noise eliminator by the sampling clock.
2.2.5 INT2 ..... Port 1 Dual-Function Input
An external test input pin. The detected edge is fixed to the rising edge. It has Schmitt-triggered input and is built
in with the noise eliminator by analog delay.
INT2 has asynchronous input. It accepts a signal having a certain high-level width irrespective of the CPU’s
operation clock if one is input.
2.2.6 PCL ..... Port 2 Dual-Function Output
A programmable clock output pin. It is used to supply the clock to the peripheral LSI. The PCL output is also
applicable to the remote control carrier signal.
The clock output function stops at RESET input and PCL turns into an input port (P22).
14
CHAPTER 2. PIN FUNCTIONS
2.2.7 X1, X2 (Crystal)
The built-in clock oscillation crystal/ceramic input.
It is also possible to supply the clock from the exterior.
(a) Crystal/Ceramic Oscillation
(b) External Clock
V
DD
µPD75402A
µPD75402A
X1
V
DD
External
Clock
X1
µPD74HC04
X2
X2
Crystal Resonator
or Ceramic Oscillator (Standard 4.194304 MHz)
2.2.8 RESET (Reset)
A low level active system reset input pin. It has Schmitt-triggered input and is built in with the noise eliminator
by analog delay.
It has asynchronous input for RESET. It accepts a signal having a certain low-level width irrespective of the CPU’s
operation clock if one is input and system reset is effected under priority over any other operation.
2.2.9 VDD
A positive power supply pin.
2.2.10 VSS
A GND potential pin.
15
CHAPTER 2. PIN FUNCTIONS
2.3 PROM MODE
The PROM mode is designatable in the µPD75P402 alone.
2.3.1 A0 to A14 (Address) ..... Input
A 15-bit address input pin at PROM write/verify, read. As the PROM built into the µPD75P402 has 2K bytes, it is
addressed by the low-order 11 bits (A0 to A10). A11 to A14 should be fixed to the low level.
2.3.2 O0 to O7 (Data) ..... Input/Output
An 8-bit data input/output pin at PROM write/verify, read.
2.3.3 CE (Chip Enable) ..... Input
A chip enable signal input pin.
2.3.4 OE (Output Enable) ..... Input
An output enable signal input pin.
2.3.5 VPP
A high voltage application pin at PROM write/verify.
It must be connected to VSS during normal operation.
2.3.6 VDD
A supply voltage application pin.
2.3.7 VSS
A GND potential pin.
16
CHAPTER 2. PIN FUNCTIONS
2.4 PIN INPUT/OUTPUT CIRCUITS
The input/output circuit of each pin is shown below in a partly simplified format.
Table 2-4 Pin Input/output Types
Input/Output Type
Pin
µPD75402A
µPD75P402
P00
B
P01/SCK
P02/SO/SB0
P03/SI
F - A
F - B
B - C
B
P10/INT0
P12/INT2
P20, P21, P23
P22/PCL
B - C
E - B
E - B
P30 to P33
P50 to P53
P60 to P63
RESET
M
M - A
E - B
B
Remarks A circle
indicates Schmitt-triggered input.
17
CHAPTER 2. PIN FUNCTIONS
Type A (for Types E - B)
Type D (for Type E - B, F - A, Y - D)
VDD
VDD
data
P-ch
P-ch
IN
OUT
N-ch
output
disable
N-ch
Push-pull output that can be turned output high
impedance (P-ch, N-ch, both off)
An input buffer of the CMOS standard
Type E - B
Type B
VDD
P.U.R.
P.U.R.
enable
P-ch
data
IN/OUT
IN
Type D
output
disable
Type A
Schmitt-triggered input having
hysteresis characteristics
P. U. R : Pull-Up Resistor
Type B - C
Type F - A
VDD
P.U.R.
P-ch
VDD
P.U.R.
enable
P.U.R.
data
IN/OUT
P.U.R.
enable
P-ch
Type D
output
disable
IN
Type B
P. U. R : Pull-Up Resistor
P. U. R : Pull-Up Resistor
18
CHAPTER 2. PIN FUNCTIONS
Type F - B
Type M - A
VDD
P.U.R.
P-ch
IN/OUT
P.U.R.
enable
output
disable
(P)
VDD
P-ch
data
N-ch (+10 V
Withstand
Voltage)
output
disable
IN/OUT
data
output
disable
N-ch
output
disable
(N)
Middle-High Voltage Input Buffer
(+10 V Withstand Voltage)
P. U. R : Pull-Up Resistor
Type M
VDD
P.U.R
(Mask Option)
IN/OUT
N-ch (+10 V
Withstand
Voltage)
data
output
disable
Middle-High Voltage Input Buffer
(+10 V Withstand Voltage)
P. U. R : Pull-Up Resistor
19
CHAPTER 2. PIN FUNCTIONS
2.5 UNUSED PIN TREATMENT
Pin
Recommended Connection Method
P00
Connect to VSS.
P01 to P03
P10 and P12
• With pull-up resistor Connect to VDD.
• Without pull-up resistor
Connect to VSS or VDD.
P20 to P23
P30 to P33
P50 to P53
• With pull-up resistor
Input status: Connect to VDD.
Output status: Leave open.
• Without pull-up resistor
Input status: Connect to VSS to VDD.
Output status: Leave open.
P60 to P63
NC
*
Leave open or connect directly to VSS.
*
If using the µPD75P402 and the printed circuit board commonly, the NC pins should be connected directly to VSS.
2.6 NOTES ON USE OF P00 PIN AND RESET PIN
The P00 and RESET pins are provided with the test mode setting function of test mode (for IC test) which tests
the internal operation of the µPD75402A in addition to the functions described in 2.2.1 and 2.2.8.
When a voltage exceeding VDD is applied to either of these pins, the test mode is set. Consequently, if noise
exceeding VDD is added even in a normal operation, the test mode is set and the normal operation may not be
continued.
For example, when wires from the P00 pin or RESET pin are long, inter-wiring noise may be added to these pins
and the pin voltage may exceed VDD, resulting in a misoperation.
Therefore, wiring should be carried out so that inter-wiring noise is suppressed as far as possible.
If it is impossible to suppress the noise, noise prevention measures by means of external parts should be taken
as shown below.
o
Insert diode with small
VF (less than 0.3 V)
between VDD and
P00/RESET pin.
o
Insert capacitor between
VDD and P00/RESET pin.
VDD
VDD
Diode with
Small VF
VDD
VDD
P00, RESET
P00, RESET
20
CHAPTER 3. FEATURES OF ARCHITECTURE AND MEMORY MAP
The µPD75402A’s architecture is a subset of the 75X architecture. Its features are outlined below.
3.1 DATA MEMORY BANK CONFIGURATION AND ADDRESSING MODES
3.1.1 Data Memory Bank Configuration
The µPD75402A’s data memory space has a bank configuration. Addresses 000H to 03FH of Bank 0 are a data
area as shown in Table 3-1 and are built in with a static RAM (64 × 4 bits). Addresses F80H to FFFH of Bank 15 are
a peripheral hardware area and are built in with the input/output port, serial interface, etc. To address this data
memory space of a 12-bit address, the low-order 8-bit address is specified directly or indirectly by an instruction.
The high-order 4-bit address is determined by the memory bank (MB) to be accessed.
The µPD75402A is built in with only Memory bank 0 and 15 and does not require bank switching unlike other
products of the 75X series. The memory bank to be accessed is determined by the addressing mode and the address
to be specified (see Tables 3-1 and 3-2).
21
CHAPTER 3. FEATURES OF ARCHITECTURE AND MEMORY MAP
Table 3-1 Data Memory Configuration and Address Range in Each Addressing Mode
Addressing
mem
mem. bit
Stack
Addressing
Mode
@ HL
fmem. bit
Data Memory
Adress
000H
003H
General
Register Area
Data Memory
Static RAM
(Memory Bank 0)
020H
03FH
Stack Area
Not built in.
F80H
Peripheral
Hardware Area
(Memory Bank 15)
FB0H
FBFH
FF0H
FFFH
22
CHAPTER 3. FEATURES OF ARCHITECTURE AND MEMORY MAP
Table 3-2 Addressing Mode List
Notation
mem. bit
Specified Address
Addressing Mode
The bit indicated by bit of the address indicated by mem. However:
Memory bank 0 is accessed if mem = 00H to 3FH.
Memory bank 15 is accessed if mem = 80H to FFH.
The address indicated by mem. However:
1-bit direct
addressing
mem
4-bit direct
addressing
Memory bank 0 is accessed if mem = 00H to 3FH.
Memory bank 15 is accessed if mem = 80H to FFH.
The address indicated by mem (mem: Even address). However:
Memory bank 0 is accessed if mem = 00H to 3EH.
Memory bank 15 is accessed if mem = 80H to FEH.
The address indicated by the content of HL of Memory bank 0. If HL = 00H to 3FH,
however.
8-bit direct
addressing
@HL
4-bit register
indirect
addressing
Bit manipulation
addressing
fmem. bit
The bit indicated by bit of the address indicated by fmem of Memory bank 15.
If the following, however:
fmem = FB0H to FBFH (interrupt, etc. hardware)
fmem = FF0H to FFFH (input/output port)
–
The address indicated by SP of Memory bank 0.
Limited to 20H to 3FH, however.
Stack
addressing
23
CHAPTER 3. FEATURES OF ARCHITECTURE AND MEMORY MAP
3.1.2 Data Memory Addressing Modes
In the µPD75402A, the 6 types of addressing modes listed on Table 3-2 are available for the data memory space
for efficient addressing per the bit length of the data to be processed.
Also in the µPD75402A, the memory bank to be accessed is fixed by the addressing mode unlike in other products
of the 75X series. So programming is possible without caring about memory bank switching.
(1) 1-bit direct addressing (mem.bit)
An addressing mode to specify each bit of the whole data memory space directly by the instruction’s operand.
The specified memory bank (MB) is MB = 0 if the address specified by the operand is 00H to 3FH and MB = 15
if it is 80H to FFH. Consequently, all the bits in both the static RAM area of 000H to 03FH and the peripheral hardware
area of FF0H to FFFH are addressable. In the peripheral hardware area, however, the bits capable of 1-bit
manipulation are limited (see Table 3-2).
This addressing mode is applied to the 4 instructions of the bit set and reset instructions (SET1, CLR1) and
testinstructions (SKT, SKF).
Example Set FLAG1, reset FLAG2 and test whether FLAG3 is 0 or not.
FLAG1 EQU
FLAG2 EQU
FLAG3 EQU
03FH.1
027H.2
017H.0
; Address 3FH, bit 1
; Address 27H, bit 2
; Address 17H, bit 0
SET1
CLR1
SKF
FLAG1
FLAG2
FLAG3
; FLAG ← 1
; FLAG ← 0
; FLAG = 0?
(2) 4-bit direct addressing (mem)
An addressing mode to specify the whole data memory space directly by the instruction’s operand per 4 bits.
The specified memory bank (MB) is MB = 0 if the address specified by the operand is 00H to 3FH and MB = 15
if it is 80H to FFH. Consequently, both the static RAM area of 000H to 03FH and the peripheral hardware area of FF0H
to FFFH are addressable.
This addressing mode is applied to the MOV, XCH, INCS, IN, and OUT instructions.
Example 1. Input Port 2 and store it in “DATA1”.
DATA1
EQU
IN
2FH
; “DATA1” is at address 2FH
A, PORT 2 ; A ← Port 2
MOV
DATA1, A
; (DATA1) ← A
2. Output the data of “BUFF” to Port 5.
BUFF
EQU
MOV
OUT
01AH
; “BUFF” is at address 01AH
A, BUFF
; A ← (BUFF)
PORT 5, A ; PORT 5 ← A
24
CHAPTER 3. FEATURES OF ARCHITECTURE AND MEMORY MAP
(3) 8-bit direct addressing (mem)
An addressing mode to specify the whole data memory space directly by the instruction’s operand per 8 bits.
The specified memory bank (MB) is MB = 0 if the address specified by the operand is 00H to 3EH and MB = 15
if it is 80H to FEH. Consequently, both the static RAM area of 000H to 03FH and the peripheral hardware area of FF0H
to FFFH are addressable. In the peripheral hardware area, however, the addresses capable of 8-bit manipulation
are limited. (See Table 3-4).
This addressing mode is applied to the MOV and XCH instructions.
Example 1. Store the serial interface shift register’s (SIO) 8-bit data at addresses 20H and 21H.
DATA
EQU
MOV
MOV
020H
XA, SIO
; XA ← SIO
DATA, XA ; (21H) ← X, (20H) ← A
2. Take the 8-bit data input to the SIO into the XA register pair as well as setting the transfer data
stored in the XA register pair.
XCH
XA, SIO
; XA ↔ SIO
(4) 4-bit register indirect addressing (@HL)
An addressing mode to specify the data memory space indirectly according to the content of the HL register per
4 bits.
The memory bank (MB) addressed in this addressing mode is fixed to to 0. Consequently, the static RAM area
of 000H to 03FH alone is addressable. The peripheral hardware area is not addressable. Data in the range of 00H
to 3FH should be set in the HL register pair.
This addressing mode is applied widely to data transfer, operation, compare, etc.
If combined with the HL register pair’s increase or decrease instruction (INCS, DECS), meanwhile, this addressing
mode allows the data memory space address to be updated freely.
Example Turn all the contents of 20H to 2FH into FH.
MOV
MOV
MOV
DECS
BR
HL, #2FH
A, #0FH
@HL, A
L
; A ← FH
; (HL) ← A
LOOP:
LOOP
Fig. 3-1 Static RAM Address Updating Method
× 0H
× FH
0 × H
DECS H
Direct
Addressing
Bit
@ HL 4-bit
Manipulation
4-bit
INCS L
DECS L
Manipulation
Transfer
8-bit
Transfer
INCS H
3 × F
25
CHAPTER 3. FEATURES OF ARCHITECTURE AND MEMORY MAP
(5) Specific address bit manipulation addressing (fmem. bit)
An addressing mode to specify each bit of the input/output port, interrupt, etc. flag, etc. of the peripheral hardware
directly by the instruction’s operand. Consequently, the data memory addresses to which this addressing mode is
applied are FB0H to FBFH, FF0H to FFFH.
While the 1-bit direct addressing mode (mem.bit) is applicable only to the bit set/reset/test instructions, this
addressing mode enables multifarious bit manipulation such as the Boolean operation by the AND1, OR1 and XOR1
instructions, test and reset by the SKTCLR instruction in addition to them.
Example 1. Test the basic interval timer interrupt request flag (IRQBT) and, if set, clear IRQBT and reset the
P63 pin level.
SKTCLR
BR
IRQBT
NO
; IRQBT = 1?
; NO
CLR1
PORT 6. 3
; YES
2. If P30 and p61 both 1, reset P53.
P30
P53
P61
(i) SET1
AND1
AND1
SKT
BR
CY
; CY ← 1
CY, PORT3. 0 ; CY∧P30
CY, PORT6. 1 ; CY∧P61
CY
; CY = 1?
SETP
PORT5. 3
CLR1
.
;P53 ← 0
.
SETP: SET1 PORT5. 3
; P53 ← 1
; P30 = 1?
; P61 = 1?
; P53 ← 0
(ii) SKT
PORT3. 0
SETP
BR
SKT
BR
CLR1
.
PORT6. 1
SETP
PORT5. 3
.
SETP: SET1 PORT5. 3
; P53 ← 1
26
CHAPTER 3. FEATURES OF ARCHITECTURE AND MEMORY MAP
(6) Stack addressing
This addressing mode is for the saving/restoring operation during the interrupting process, subroutine process.
The data memory is addressed indirectly according to the content of the stack pointer (SP : 8 bits).
The memory bank (MB) addressed in this addressing mode is fixed to 0. Also as the stack pointer’s high-order
3 bits are fixed to 001, the addressable area is limited to 020H to 03FH.
This addressing mode is also applied at register save/restore by the PUSH, POP instruction in addition to the
interrupting process, subroutine process.
Note The Evachip packaged on the board for evaluation can address the whole area of Memory bank 0 in this
addressing mode unlike in the µPD75402A. To eliminate such a difference during the evaluation, a value
not to access beyond the range of 20H to 3FH should be set in the stack pointer.
Example 1. Save/restore the register during the subroutine process.
SUB:
PUSH
PUSH
XA
HL
POP
POP
RET
HL
XA
2. Transfer the content of the HL register pair to the XA register pair.
PUSH
POP
HL
XA
; XA ← HL
3. Branch to the address indicated by the (XAHL) register.
PUSH
PUSH
RET
HL
XA
; Branch to address XAHL
27
CHAPTER 3. FEATURES OF ARCHITECTURE AND MEMORY MAP
3.2 MEMORY-MAPPED I/O
The µPD75402A adopts memory-mapped I/O to map such peripheral hardware as the input/output port, serial
interface at addresses F80H to FFFH in the data memory space shown in Table 3-1. As a result, there is no special
instruction to control the peripheral hardware; the peripheral hardware is controlled wholly by memory manipu-
lation instructions (some hardware control mnemonics are available to make the program easy to understand).
Table 3-3 shows the addressing modes available when operating the peripheral hardware.
Table 3-3 Applicable Addressing Modes at Peripheral Hardware Operation
Applicable Addressing Mode
Specify the bit to be manipulated by the direct
addressing mem.bit.
Applicable Hardware
All the hardware capable of bit
manipulation
Bit manipulation
Specify the bit to be manipulated by the direct
addressing fmem.bit.
IE×××, IRQ×××, PORTn.×
Specify the address to be manipulated by the direct
addressing mem.
All the hardware capable of 4-bit
manipulation.
4-bit manipulation
8-bit manipulation
Specify the address to be manipulated by the direct
addressing mem. Mem is an even address, however.
All the hardware capable of 8-bit
manipulation.
Table 3-4 summarizes the µPD75402A’s I/O map. The items shown in this table have the following meaning.
• Symbol:
A name to indicate the address of the built-in hardware. It can be described in
the instruction’s operand column. IME is excepted, however.
• Number of manipulatable bits: The number of applicable processing bits when operating the relevant
hardware. Such symbols as R/W, indicate whether the relevant hardware is
readable/writable or not.
R/W : Readable/Writable
R
: Readable
: Writable
W
• Bit manipulation addressing:
The applicable bit manipulation addressing when bit manipulating the relevant
hardware.
28
CHAPTER 3. FEATURES OF ARCHITECTURE AND MEMORY MAP
Table 3-4 µPD75402A I/O Map (1/2)
No. of Manipulatable
Addressing
Hardware Name (Symbol)
Bit
Remarks
Address
F80H
Manipula-
tion
1 Bit
4 Bits
8 Bits
b3
b2
b1
b0
Bit 0 is fixed to 0.
Stack pointer (SP)
W
11 must always
be written in
bit 1, 0.
F85H
F86H
W
Basic interval timer mode register (BTM)
Basic interval timer (BT)
R
Manipulation
by EI. DI instruc-
tion
FB2H
(IME)
FB3H
FB4H
FB8H
FBDH
FBEH
FBFH
Processor clock control register (PCC)
INT0 mode register (IM0)
W
W
Bit 2 is fixed to 0.
0
0
0
0
0
0
0
0
IEBT
IECSI
IE0
IRQBT
IRQCSI
IRQ0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
fmem. bit
IE2
IRQ2
FD0H
FDCH
Clock output mode register (CLOM)
W
Pull-up resistor specify register
Group A (POGA)
W
Remarks 1. IE××× is an interrupt enable flag.
2. IRQ××× is an interrupt request flag.
29
CHAPTER 3. FEATURES OF ARCHITECTURE AND MEMORY MAP
Table 3-4 µPD75402A I/O Map (2/2)
No. of Manipulatable
Addressing
Hardware Name (Symbol)
Bit
Remarks
Address
Manipula-
tion
1 Bit
4 Bits
8 Bits
b3
b2
b1
b0
FE0H
FE1H
FE2H
FE3H
FE4H
Serial operation mode register (CSIM)
W
0 must always be
written in bit 0.
* 1
* 2
* 3
mem. bit
mem. bit
CSIE
COI
WUP
0
CMDD
RELD
CMDT
RELT
Bit manipulation
only is possible
for all the bits.
SBI control register (SBIC)
BSYE ACKD ACKE
ACKT
Serial I/O shift register (SIO)
Slave address register (SVA)
R/W
W
11000 must
FE6H
FE8H
FECH
always be written
in the high-order
5 bits.
Port mode register Group A (PMGA)
Port mode register Group B (PMGB)
W
W
FF0H
FF1H
FF2H
FF3H
FF5H
FF6H
R
R
Port 0 (PORT 0)
Port 1 (PORT 1)
Port 2 (PORT 2)
Port 3 (PORT 3)
Port 5 (PORT 5)
Port 6 (PORT 6)
Bits 3 and 1 are
fixed to 0.
R
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
fmem. bit
*
1. Bits 3 and 1: W; bit 2: R.
2. Bits 3 and 2: R; bits 1 and 0: W.
3. Bits 3 and 1: R/W; bit 2: R; bit 0: W.
30
CHAPTER 4. INTERNAL CPU FUNCTIONS
4.1 PROGRAM COUNTER (PC) ..... 11 BITS
An 11-bit binary counter to hold the program memory address information.
Fig. 4-1 Program Counter Configuration
PC10 PC9
PC8
PC7
PC6
PC5
PC4
PC3
PC2
PC1
PC0
The program counter operates as follows.
• Normal operation
The content is incremented automatically according to the number of bytes of the instruction every time one is
executed.
• Branch instruction (BR, BRCB) execution
The immediate data indicating the address of the destination of branching is set in the PC.
• Subroutine call instruction (CALLF) execution and vector interrupt
The content of the PC at that time is saved in the stack memory and then the address of each destination of
branching is set in the PC.
• Return instruction (RET, RETS, RETI) execution
The content of the stack memory is set in the PC.
• RESET input
The low-order 3 bits of the program memory’s address 000H is set in PC10 to PC8 and the content of address
001H is set in PC7 to PC0 and then initialized. It is possible to start the program from any address.
31
CHAPTER 4. INTERNAL CPU FUNCTIONS
4.2 PROGRAM MEMORY (ROM) ..... 1,920 WORDS × 8 BITS
A mask programmable ROM of a 1,920-word × 8-bit configuration. It stores the program, table data, etc.
The program memory is addressed by the program counter. It is also possible to read the table data in the ROM
by the table refer instruction (MOVT).
It is possible to branch to any area of the program memory by the branch instruction, subroutine call instruction
(see Fig. 4-2). With the relative branch instruction (BR $addr), it is possible to branch to the range of (-15 to -1, +2
to +16) from the address indicated by the PC after the instruction execution.
The program memory’s addresses cover 000H to 77FH and the addresses shown below are assigned specially.
All the areas excluding 000H and 001H are available as the normal program memory.
Fig. 4-2 Program Memory Map
Address
0 0 0 H
7
0
6
0
5
0
4
0
3
0
0
Reset Start Address
(high-order 3 bits)
0 0 1 H
0 0 2 H
0 0 3 H
Reset Start Address (low-order 8 bits)
INTBT Start Address
(high-order 3 bits)
0
0
0
0
0
0
CALLF !faddr
Instruction Entry
Address
INTBT Start Address (low-order 8 bits)
INT0 Start Address
(high-order 3 bits)
0 0 4 H
0 0 5 H
0
0
0
0
INT0 Start Address (low-order 8 bits)
BRCB !caddr
Instruction Branch
Address
INTCSI Start Address
(high-order 3 bits)
0 0 8 H
0 0 9 H
0
0
0
0
0
BR $addr
Instruction Relative
Branch Address
INTCSI Start Address (low-order 8 bits)
–15 to –1
+2 to +16
~
~
~
~
7 7 F H
32
CHAPTER 4. INTERNAL CPU FUNCTIONS
4.3 DATA MEMORY (RAM)
The data memory consists of the data and peripheral hardware areas as shown in Fig. 4-3.
Fig. 4-3 Data Memory Map
Data Memory
0 0 0 H
Memory Bank
General
Register Area
(4 × 4)
0 0 3 H
0 0 4 H
Data Area
Static RAM
(64 × 4)
Bank 0
0 2 0 H
0 3 F H
(64 × 4)
(32 × 4)
Stack Area
Not built in.
F 8 0 H
Peripheral
Hardware
Area
Bank 15
128 × 4
F F F H
(1) Data area
The µPD75402A’s data area consists of the static RAM (64 words× 4 bits). The data area is used to store processing
data and is operated by the memory manipulation instruction.
The static RAM is mapped to Memory bank 0 by 64 × 4 bits. While Bank 0 is mapped as the data area, it is also
available as the general register area (000H to 003H) and the stack area (020H to 03FH).
In the static RAM, 1 address consists of 4 bits. It is possible either to operate per 8 bits by the 8-bit memory
manipulation instruction or to operate per bit by the bit manipulation instruction, however. In the 8-bit manipulation
instruction, an even address should be specified.
• General register area
Operation is possible either by the general register manipulation instruction or by the memory manipulation
instruction. Up to four 4-bit registers are available. Of the 4 general registers, that part which is not used in the
program is available as the data area (see 4.4 “GENERAL REGISTER”).
• Stack area
The stack area is set by an instruction and is available as the save area at the subroutine or interrupting process
execution (see 4.6 “STACK POINTER”). In that case, the stack area is at the static RAM’s addresses 020H to 03FH.
33
CHAPTER 4. INTERNAL CPU FUNCTIONS
(2) Peripheral hardware area
The peripheral hardware area is mapped to memory bank 15’s addresses F80H to FFFH.
The operation is performed by the memory manipulation instruction just as in the static RAM. In the peripheral
hardware, however, the operable bit unit differs from one address to another. It is impossible to access an address
to which the peripheral hardware is not assigned since the data memory is not built in. (See Table 3-4 “µPD75402A
I/O Map".)
Note The static RAM is indefinite at reset. Therefore, it should be initialized to zero at the beginning of the
program (RAM clear). This must be carried out for sure to avoid unexpected bugs.
Example Clear all the areas (00H to 3FH) of the static RAM (FFH remains in the HL register, however).
MOV
MOV
MOV
DECS
BR
HL, #3FH
A, #0H
LOOP:
@HL, A: Clear (0) 00H to 3FH
L
LOOP
H
DECS
BR
LOOP
34
CHAPTER 4. INTERNAL CPU FUNCTIONS
4.4 GENERAL REGISTER ..... 4 × 4 BITS
The general register is assigned to a specific address of the data memory. There are four 4-bit registers (H, L,
X, A).
While each general register is operated per 4 bits, HL and XA make up register pairs, each of which is operated
per 8 bits. The HL register pair is available as the data pointer to indirectly address the memory.
The general register area can be addressed and accessed as an ordinary RAM regardless of whether it is used
as a register or not.
Fig. 4-4 General Register Configuration
X
A
L
0 1 H
0 3 H
0 0 H
0 2 H
H
Remarks The figure in the lower right corner is the assigned data memory address.
Fig. 4-5 Register Pair Configuration
3
3
0
3
0
0
H
X
L
0
3
A
35
CHAPTER 4. INTERNAL CPU FUNCTIONS
4.5 ACCUMULATOR
In the µPD75402A, the A register and the XA register pair function as accumulators. The 4-bit data process
instruction is executed mainly by the A register and the 8-bit data process instruction is executed mainly by the XA
register pair.
In the bit manipulation instruction, the carry flag (CY) functions as the bit accumulator.
Fig. 4-6 Accumulators
Bit Accumulator
4-Bit Accumulator
8-Bit Accumulator
CY
A
A
X
36
CHAPTER 4. INTERNAL CPU FUNCTIONS
4.6 STACK POINTER (SP) ..... 8 BITS
The µPD75402A uses a static RAM as the stack memory (LIFO format). The 8-bit register holding the top address
information of such a stack memory area is the stack pointer (SP). Fig. 4-7 shows its format.
As the SP’s high-order 3 bits are fixed to 001, the stack area is at the static RAM’s addresses 020H to 03FH.
The SP is decremented before write (save) in the stack memory and is incremented after read (restore) from the
stack memory. Figs. 4-8 and 4-9 show the data saved and restored by each stacking operation.
The SP sets the initial value by the 8-bit data transfer instruction to determine the stack area. It is impossible to
read the content of the SP.
Zero is always written in the SP’s bit 0.
It is recommended to initialize by writing 40H in the SP and use the built-in RAM’s maximum address (03FH) and
beyond as the stack area.
The content of the SP turns indeterminate at RESET input, so it must be initialized to your desired value by the
program initialization routine.
Note The SP of the Evachip packaged on the board for evaluation can address all the areas of 000H to 0FFH unlike
in the µPD75402A. To eliminate such a difference at evaluation, the SP should be set not to access beyond
the range of 020H to 03FH.
Example SP initialize
MOV
MOV
XA, #40H
SP, XA
; SP ← 40H
Fig. 4-7 Stack Pointer Configuration
Address
F80H
7
0
6
0
5
1
4
3
2
1
0
Symbol
SP
SP4
SP3
SP2
SP1
SP0
↑
0 Fixed
37
CHAPTER 4. INTERNAL CPU FUNCTIONS
Fig. 4-8 Data Saved to Stack Memory
PUSH Instruction
Stack
CALLF Instruction
Interrupt
Stack
Stack
SP - 6
0
0
PC10 - PC8
0
0
PC10 - PC8
SP - 4
0
0
0
SP - 5
SP - 4
SP - 3
SP - 2
0
0
0
0
SP - 3
SP - 2
Register Pair
Low Order
SP - 2
PC3 - PC0
PC7 - PC4
PC3 - PC0
PC7 - PC4
Register Pair
High Order
SP - 1
SP
SP - 1
SP
0
IST0
PSW
SK2 SK1 SK0
0
CY
SP - 1
SP
Fig. 4-9 Data Restored from Stack Memory
POP Instruction
Stack
RET, RETS Instruction
RETI Instruction
Stack
Stack
Register Pair
Low Order
0
0
PC10 - PC8
0
0
PC10 - PC8
SP
SP
SP
Register Pair
High Order
0
0
0
0
0
0
0
SP + 1
SP + 2
SP + 1
SP + 2
SP + 3
SP + 4
SP + 1
SP + 2
SP + 3
SP + 4
PC3 - PC0
PC7 - PC4
PC3 - PC0
PC7 - PC4
0
IST0
PSW
SK2 SK1 SK0
0
CY
SP + 5
SP + 6
38
CHAPTER 4. INTERNAL CPU FUNCTIONS
4.7 PROGRAM STATUS WORD (PSW) ..... 8 BITS
The program status word (PSW) consists of various flags concerning closely the processor operation. Fig. 4-10
shows its configuration.
Saved to the stack memory per 8 bits at the interrupt acceptance and restored from the stack memory per 8 bits
at the RETI instruction execution (see Figs. 4-8 and 4-9).
Fig. 4-10 Program Status Word Configuration
7
6
5
4
3
0
2
1
0
0
0
CY
SK2
SK1
SK0
IST0
Interrupt Status Flag
Skip Flag
Carry Flag
The PSW is not assigned to the data memory space. So it is impossible to operate each flag by the memory
manipulation instruction. The carry flag (CY) alone is operable by a dedicated instruction, however.
IST0 turns 0 and SK0 to SK2 and CY turn indeterminate at RESET input.
(1) Carry flag (CY)
The carry flag is a 1-bit flag to store the overflow occurrence information at the operation instruction with carry
(ADDC) execution.
The carry flag also has the function of the bit accumulator, so it can perform Boolean operation with the bit address
specify data memory and can store its results.
The carry flag is operated by a dedicated instruction irrespective of the other PSW bits.
The carry flag turns indeterminate with the RESET input.
Table 4-1 Carry Flag Manipulation Instructions
Instruction (Mnemonic)
SET1 CY
Carry Flag Operation, Process
Carry flag manipulation
dedicated
Set (1) CY
CLR1 CY
Clear (0) CY
NOT1 CY
Invert the content of CY
SKT CY
Skip if the content of CY is 1
Bit Boolean instruction
Interrupting process
AND1 CY, fmem.bit
OR1 CY, fmem.bit
XOR1 CY, fmem.bit
At interrupt execution
Take AND/OR/XOR of the contents bit of the specified bit and CY
and store the result in CY
Save to the stack memory in 8 bits parallel to the other PSW bits
---------------------------------------------------------------------------------------------------------
RETI
Restore from the stack memory in parallel to the other PSW
39
CHAPTER 4. INTERNAL CPU FUNCTIONS
Example Take AND of bit 3 at address 3FH and P33 and set the result in CY.
SET1
SKT
CY
; CY← 1
3FH. 3
; Skip if bit 3 at address 3FH is 1
CLR1
AND1
CY
; CY← 0
; CY← CY∧P33
CY, PORT 3. 3
(2) Skip flag (SK2, SK1, SK0)
The skip flag is a flag to store the skip status. It is set/reset automatically as the CPU executes an instruction.
It is impossible for the user to operate it directly by the program.
(3) Interrupt status flag (IST0)
The interrupt status flag is a flag to store the status of the process under execution (for details, see Table 6-3).
It is impossible for the user to operate it directly by the program.
Table 4-2 Interrupt Status Flag Indication Content
Status of Process
under Execution
Processing Content and
Interrupt Control
IST0
0
1
Status 0
In a normal programming process.
Enable to accept any interrupt.
Status 1
In an interrupting process.
Disable to accept any interrupt.
The content of IST0 is saved to the stack memory as part of the PSW if the interrupt is accepted and then set
automatically to 1 and set to 0 by the RETI instruction.
As it is impossible to operate IST0 by an instruction, it is always that IST0 = 1 during the interrupting process.
So it is impossible to multiplex interrupts, all the interrupt requests having occurred during the interrupting process
are pending until the interrupting process under execution ends (for details, see CHAPTER 6 “INTERRUPT
FUNCTIONS”).
40
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.1 DIGITAL INPUT/OUTPUT PORTS
The µPD75402A has the following digital input/output ports on chip: Ports 0 through 3, 5 and 6.
The µPD75402A uses memory mapped I/O, and all input/output ports are mapped onto data memory space.
All data memory handling instructions can be used on all of the ports, and a wide variety of bit operations can
be performed in addition to 4-bit input/output.
Note On the µPD75402A it is not possible to perform 8-bit input/output by pairing two ports.
Fig. 5-1 Digital Input/Output Port Data Memory Addresses
Address
FF0H
3
2
1
0
Symbol
PORT0
PORT1
PORT2
PORT3
P03
0
P02
P12
P22
P32
P01
0
P00
P10
P20
P30
FF1H
FF2H
P23
P33
P21
P31
FF3H
FF5H
FF6H
P53
P63
P52
P62
P51
P61
P50
P60
PORT5
PORT6
41
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.1.1 Digital Input/Output Port Types, Characteristics and Configuration
The different types of digital input/output ports are shown in Table 5-1, and the configuration of each port is shown
in Figs. 5-2, 5-3, 5-4 and 5-5.
Table 5-1 Digital Input/Output Port Types and Characteristics
Port
(Symbol)
Function
4-bit input
Operation/Characteristics
Remarks
PORT0
PORT1
Can always be read or tested
regardless of dual-function pin
operating mode.
Pins also function as SO/SB0, SI,
SCK, INT0, INT2. (See chapter 1.)
PORT3*
4-bit input/output
Can be set to input or output
mode bit by bit.
PORT2
PORT6*
Can be set to input or output
mode as a 4-bit unit.
Port 2 pins also function as PCL.
PORT5*
4-bit input/ output
(N-ch open-drain,
up to 10 V)
Can be set to input or output
mode as a 4-bit unit.
Internal pull-up resistor can be
specified bit by bit by mask
option. (µPD75402A only.)
*
LED direct drive capability
On the µPD75402A, a pull-up resistor can be incorporated on chip for all port pins except pins P00, P10. On the
µPD75P402, a pull-up resistor can be incorporated on chip for all port pins except pins P00, P10, and P50 through
P53 (see section 5.5).
P10 has a dual function as the external vectored interrupt input pin, and has an on-chip circuit for noise elimination
by the sampling clock (see section 6.2 for details).
Upon RESET input the output latches of ports 2, 3, 5 and 6 are cleared, the output buffer is turned off, and input
mode is set.
42
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Fig. 5-2 Configuration of Ports 0 and 1
Internal
SCK
SI
SCK
SO
VDD
Pull-Up
Resistors
Selcetor
CSIM
POGA
Bit 0
P-ch
P00
PO0
P01/SCK
P02/SO/SB0
P03/SI
Output Buffer with Capability
of Switching between Push-Pull
Output and N-ch Open-Drain Output
Input Buffer
VDD
Pull-Up
Resistor
POGA
Bit 1
PO1
P-ch
Input Buffer
or fXX/64
Φ
P10/INT0
P12/INT2
Noise Elimination Circuit
Input Buffer with
Hysteresis Characteristics
INT2
INT0
43
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Fig. 5-3 Configuration of Port 3
VDD
PM 3 n=0
PM 3 n=1
Input Buffer
Pull-Up
Resistor
M
P
X
POGA
Bit 3
PO3
P-ch
Output
Buffer
P 3 n
Output Latch
PM 3 n
PMGA Bit n
Remarks n = 0 to 3
44
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Fig. 5-4 Configuration of Ports 2 and 6
VDD
Pull-up
Resistors
POGA
Bit m
P-ch
POm
Input Buffer
PMm = 0
M
P
PMm = 1
X
P m 0
P m 1
P m 2
P m 3
Output
Buffer
*
PM2/
PM60 to
63
PMGB Bit 2,
PMGA bits
4 to 7
*
Input/output mode specification is performed by bit 2 (PM2) of PMGB for port 2 and by bits 4 to 7 (PM60 to 63)
of PMGA for port 6.
Remarks m = 2 or 6
45
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Fig. 5-5 Configuration of Port 5
VDD
Pull-Up Resistors
(Mask Option; µPD75402A
Only)
Input Buffer
PM5=0
M
P
X
PM5=1
P50
P51
P52
P53
N-ch
Open-Drain
Output
Buffer
PM5
PMGB
Bit 5
5.1.2 Input/Output Mode Setting
The input/output mode for each input/output port is set by a port mode register as shown in Fig. 5-6. For port
3, input/output can be specified bit by bit by port mode register group A (PMGA). Input/output is specified in 4-bit
units by PMGB for ports 2 and 5, and by PMGA for port 6.
Each port operates as an input port when the corresponding port mode register bit is “0”, and as an output port
when “1”.
Since, when output mode is selected by setting the port mode register, the output latch contents are simulta-
neously output to the output pin, the output latch contents must be overwritten in advance with the required value
before output mode is set.
Port mode register group A and B are each set by an 8-bit memory handling instruction.
With a RESET input, all bits of each port mode register are cleared to zero, and thus the output buffer is turned
off and all ports are set to input mode.
46
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Fig. 5-6 Format of Port Mode Registers
Port Mode Register Group A
Address
7
6
5
4
3
2
1
0
Symbol
PMGA
FE8H PM63 PM62 PM61 PM60 PM33 PM32 PM31 PM30
P30 Input/Output Specification
P31 Input/Output Specification
P32 Input/Output Specification
P33 Input/Output Specification
Port 6 (P60 to P63) Input/Output Specification*
Port Mode Register Group B
Address
FECH
7
6
5
4
3
2
1
0
Symbol
PMGB
—
—
PM5
—
—
PM2
—
—
Port 2 (P20 to P23) Input/Output Specification
Port 5 (P50 to P53) Input/Output Specification
Specification
0
1
Input mode (output buffer off)
Output mode (output buffer on)
*
Port 6 input/output specification is performed as a 4-bit unit. Ensure that 0000 or 1111 is written to PMGA bits
7 through 4.
5.1.3 Digital Input/Output Port Handling Instructions
As all the input/output ports in the µPD75402A are mapped onto data memory space, all data memory handling
instructions can be used. Those data memory handling instructions which are considered particularly useful for
input/output pin operations are shown in Table 5-2 together with their scope of application.
47
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(1) Bit handling instructions
Direct addressing of specific address bits (fmem.bit) can be used on all digital input/output ports.
Example To OR P50 and P31 and output the result to P61.
SET1
AND1
OR1
SKT
CY
; CY ← 1
; CY ← CY ∧ P50
; CY ← CY ∨ P31
CY, PORT5.0
CY, PORT3.1
CY
BR
CLRP
SET1
PORT6.1
; P61 ← 1
CLRP : CLR1
PORT6.1
; P61 ← 0
(2) 4-bit handling instructions
All 4-bit memory handling instructions can be used, such as MOV, XCH, ADDS and INCS, in addition to the IN/
OUT instructions.
Example 1. To output accumulator contents to port 3.
OUT
PORT3, A
2. To add the accumulator value to the data output to port 5, and output the result.
MOV
ADDS
NOP
HL, #PORT5
A, @HL
; A ← A + PORT5
MOV
@HL, A
; PORT5 ← A
Table 5-2 List of Input/Output Pin Handling Instructions
PORT 0
PORT 1
PORT2
PORT 3
PORT5
PORT 6
IN A, PORTn
●
OUT PORTn, A
SET1 PORTn.bit
CLR1 PORTn.bit
–
–
–
–
–
–
●
●
●
SKT
SKF
PORTn.bit
PORTn.bit
●
●
●
●
●
AND1 CY, PORTn.bit
OR1 CY, PORTn.bit
XOR1 CY, PORTn.bit
48
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.1.4 Digital Input/Output Port Operations
Port and port pin operations when a data memory handling instruction is executed for a digital input/output port
differ according to the input/output mode setting (see Table 5-3). This is because, as can be seen from the input/
output port configurations, data fetched onto the internal bus is treated as pin data in input mode and as output
latch data in output mode.
(1) Operations when input mode is set
When a test instruction such as the SKT instruction, or an instruction which fetches port data as 4 bits onto the
internal bus (IN, MOV and bit operation instructions) is executed, individual pin data is manipulated.
When an instruction which performs a 4-bit transfer of accumulator contents to a port (OUT or MOV instruction)
is executed, the accumulator data is latched in the output latch. The output buffer remains off.
When an XCH instruction is executed, the individual pin data is input to the accumulator, and the accumulator
data is latched in the output latch. The output buffer remains off.
When an INCS instruction is executed, data comprising the individual pin data (4-bit) + 1 is latched in the output
latch. The output buffer remains off.
When a bit-wise data memory rewriting instruction such as the SET1/CLR1/SKTCLR instructions is executed, the
output latch for the specified bit can be rewritten as directed by the instruction, but the contents of the output latches
for the other bits are undefined.
(2) Operations when output mode is set
When a test instruction, bit input instruction, or an instruction which fetches port data as 4 bits onto the internal
bus is executed, the output latch contents are manipulated.
When an instruction which performs a 4-bit transfer of accumulator contents is executed, when the output latch
data is overwritten it is simultaneously output from the pins.
When an XCH instruction is executed, the output latch contents are transferred to the accumulator, and the
accumulator contents are latched in the output latches and output from the pins.
When an INCS instruction is executed, data comprising the output latch contents + 1 is latched in the output
latches and output from the pins.
When a bit output instruction is executed, the specified output latch bit is rewritten and output from the pin.
49
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Table 5-3 Operations with Input/Output Port Handling Instructions
Port and Individual Pin Operations
Instruction Executed
Input Mode
Tests pin data.
Output Mode
Tests output latch data.
SKT
SKF
PORTn.bit
PORTn.bit
Operation between pin data and
CY
Operation between output latch
data and CY
AND1 CY, PORTn.bit
OR1 CY, PORTn.bit
XOR1 CY, PORTn.bit
Transfers pin data to accumula-
tor.
Transfers output latch data to
accumulator.
IN
A, PORTn
MOV A, PORTn
Transfers accumulator data to
output latches. (Output buffer
remains off.)
Transfers accumulator data to
output data to output latches,
and outputs data from pins.
OUT PORTn, A
MOV PORTn, A
Transfers pin data to accumula-
tor, and transfers accumulator
data to output
Exchanges data between output
latches and accumulator.
XCH A, PORTn
latches. (Output buffer remains
off.)
Latches pin data + 1 in output
latches.
Increments output latch contents
by 1.
INCS PORTn
Specified bit output latch is
rewritten as per instruction,
but output latches for other bits
are undefined.
Changes output pin status as per
instruction.
SET1 PORTn.bit
CLR1 PORTn.bit
SKTCLR PORTn.bit
50
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.1.5 Internal Pull-up Resistors
The µPD75402A can incorporate internal pull-up resistors for all port pins except P00 and P10. The µPD75P402
can incorporate internal pull-up resistors for all port pins except P00, P10, and P50 through P53.
As shown in Table 5-4, internal pull-up resistors can be specified by software or by a mask option (although
specification by mask option is not possible on the µPD75P402).
The pull-up resistor specification register which specifies internal pull-up resistors for ports 0 through 3 and 6
(POGA) is an 8-bit write-only register. Its format is shown in Fig. 5-7. POGA is set by an 8-bit write instruction. Reading
and bit manipulation is not possible. RESET input clears this register to zero.
Internal pull-up resistor specification for port 3 is valid only for input pins specified as in input mode. The status
of pins specified as in output mode is “without pull-up resistor” irrespective of the POGA setting.
Table 5-4 Internal Pull-Up Resistor Specification for Each Port
Port (Pin Name)
Port 0 (P01 to P03)*1
Port 1 (P12)*1
Internal Pull-Up Resistor Specification Method
3-bit unit internal specification by software
Internal specification by software
Specification Bits
POGA.0
POGA.1
Port 2 (P20 to P23)
Port 3 (P30 to P33)
Port 6 (P60 to P63)
4-bit unit internal specification by software
POGA.2
POGA.3
POGA.6
Port 5 (P50 to P53)
Bit-wise internal specificationby mask option*2
*
1. Pull-up resistors cannot be incorporated into the P00 and P10 pins.
2. On the µPD75P402, pull-up resistors cannot be incorporated into port 5.
51
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Fig. 5-7 Format of Pull-Up Resistor Specification Register
Address
FDCH
7
–
6
5
–
4
–
3
2
1
0
Symbol
POGA
PO6
PO3
PO2
PO1
PO0
Port 0 (P01 to P03)
Port 1 (P12)
Port 2 (P20 to P23)
Port 3 (P30 to P33)
Port 6 (P60 to P63)
Specification
0
1
Pull-up resistor not incorporated
Pull-up resistor incorporated
The timing for switching of pull-up resistor presence/ absence by the setting of the pull-up resistor specification
register (POGA) is shown in Fig. 5-8.
Fig. 5-8 Pull-Up Resistor Incorporation Switching Timing
2-Machine Cycles
Φ 3
Φ
0
Φ 1
Instruction
Execution
Manipulation Instruction
POGA
Remarks Φo through Φ3 are internal operation timing clock pulses.
After pull-up resistor incorporation has been specified by overwriting POGA, in consideration of the external load
capacity the pin level should be stabilized by execution of an NOP instruction etc. before an input/output instruction
is executed.
Example To perform input after specifying incorporation of a pull-up resistor in port 1.
MOV
MOV
XA, #02H
; Pull-up resistor incorporated in port 1
POGA, XA
Wait until pin level is stabilized in consideration of
external load capacity.
IN
A, PORT1
52
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.1.6 Digital Input/Output Port Input/Output Timing
The timing for outputting data to the output latch and fetching pin data or output latch data onto the internal bus
is shown in Fig. 5-9.
Fig. 5-9 Digital Input/Output Port Input/Output Timing
(a) Data fetch by 1-machine-cycle instruction
1-Machine Cycles
Instruction
Execution
Manipulation
Instruction
Input Timing
(b) Data fetch by 2-machine-cycle instruction
2-Machine Cycles
Instruction
Execution
Manipulation Instruction
Input Timing
(c) Data latching by 1-machine-cycle instruction
Φ 3
Manipulation Instruction
Φ
0
Φ
1
Instruction
Execution
Output Latch
(Output Pin)
(d) Data latching by 2-machine-cycle instruction
Φ 0
Φ
1
Instruction
Execution
Manipulation Instruction
Output Latch
(Output Pin)
53
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.2 CLOCK GENERATION CIRCUIT
The clock generation circuit supplies various clocks to the CPU and peripheral hardware, and controls the
operating mode of the CPU.
5.2.1 Clock Generation Circuit Configuration
The configuration of the clock generation circuit is shown in Fig. 5-10.
Fig. 5-10 Clock Generation Circuit Block Diagram
★
• Basic Interva Timer (BT)
• Clock Output Circuit
• Serial Interface
• INT0 Noise Eliminator
• Clock Output Circuit
X1
VDD
System
Clock
1/16 to 1/512
fXX or fX
Oscillation
Circuit
Frequency Divider
1/2 1/16
X2
STOP
Oscillation
Frequency
Divider
Φ
1/4
• CPU
• INT0 Noise
Eliminator
• Clock Output
Circuit
PCC
PCC0
PCC1
PCC2
4
HALT F/F
S
HALT*
PCC3
STOP*
R
Q
Clear
all bits
RESET Input Rising Edge
Detection Signal
STOP F/F
Clear
PCC2
Q
S
RESET Input Falling Edga
Detection Signal
R
Standby Release Signal from
Interrupt Control Circuit
Remarks 1. fXX = System clock frequency
2. fX = External clock frequency
3. PCC: Processor clock control register
4. 1 clock cyck (fCY) of Φ is 1 machine cycle of an instruction.
Instruction execution
*
54
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.2.2 Clock Generation Circuit Function and Operaion
The clock generation circuit generates the CPU clock ( Φ ) and various clocks for supply to peripheral hardware,
and controls the CPU operating mode, such as standby mode etc.
Clock generation circuit operation is determined by the processor clock control register (PCC).
Upon RESET input, the PCC is cleared to 0000 and the µPD75402A operates in low-speed mode (15.3 µs: when
operating at 4.19 MHz).
Peripheral hardware is supplied with various clocks scaled from the system clock generation circuit output (fXX
in the case of crystal/ceramic oscillation, and fX when an external clock is used) by the frequency divider.
From this section on, only fXX is used when expressing the speed of the various clocks; for an external clock, this
should be replaced by fX.
The operation of each block is described below.
(1) Processor clock control register (PCC)
The PCC is a 4-bit register which performs selection of the CPU clock Φ and control of the CPU operating mode.
The format of the PCC is shown in Fig. 5-11.
When bit 3 or bit 2 is set (1), standby mode is selected. When standby mode is released by the Standby Release
signal, both bits are automatically cleared and the normal operating mode is reestablished (see CHAPTER 7
“STANDBY FUNCTION” for details).Setting of the low-order 2 bits of the PCC is performed by a 4-bit memory
handling instruction. At this time, ensure that bits 3 and 2 are reset to “0” so that the pattern “00××” is written.
Bits 3 and 2 are set (1) by the STOP instruction and the HALT instruction respectively.
RESET input clears the PCC to 0000.
Example 1. To set the machine cycle to 0.95 µs (fXX = 4.19 MHz).
SEL
MB15
MOV
MOV
A, #0011B
PCC, A
2. To set the machine cycle to 1.63 µs (fXX = 4.91 MHz).
SEL
MB15
MOV
MOV
A. # 0010B
PCC, A
3. To select the STOP mode. (Be sure to include an NOP instruction after a STOP or HALT instruction.)
STOP
NOP
55
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Fig. 5-11 Processor Clock Control Register Format
Address
FB3H
3
2
1
0
Symbol
PCC
PCC3 PCC2 PCC1 PCC0
CPU clock selection bits when fXX ≤ 4.19 MHz
(
) : When fXX = 4.19 MHz
CPU Clock Frequency
Φ Output = fXX/64 (65.5 kHz)
Setting prohibited
1 Machine Cycle
15.3 µs
–
0
0
1
1
0
1
0
1
Φ = fXX/8 (524 kHz)
Φ = fXX/4 (1.05 MHz)
19.1 µs
0.95 µs
When 4.19 MHz < fXX ≤ 5.0 MHz
(
) : When fXX = 4.19 MHz
CPU Clock Frequency
1 Machine Cycle
0
0
1
1
0
1
0
1
Φ Output = fXX/64 (76.7 kHz)
Setting prohibited
13 µs
–
1.63 µs
–
Φ = fXX/8 (614 kHz)
Setting prohibited
fXX : Main system clock oscillation circuit output frequency
CPU operating mode control bit
0
0
1
1
0
1
0
1
Normal operating mode
HALT mode
STOP mode
Setting prohibited
Note When using a calue of fXX such that 4.19 MHz < fXX ≤ 5.0 MHz, if maximum speed mode : Φ fXX/4 (PCC1, PCC0
= 11) is set as CPU clock frequency, 1 machine cycle is less than 0.95 µs and the standard minimum value
0.95 µs is not kept.
Therefore, is this case, PCC1, PCC0 = 11 cannot be set, so it should be used with PCC1, PCC0 = 00 or 10.
As a result, the combination of “fXX = 4.19 MHz, PCC1, PCC0 = 11” is maximum speed selection (1 machin
cycle = 0.95 µs) as CPU clock.
56
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(2) System clock oscillation circuit
The system clock oscillation circuit oscillates by means of a crystal resonator or ceramic resonator connected
to the X1 and X2 pins (standard: 4.194304 MHz).
An external clock can also be input.
Fig. 5-12 System Clock Oscillation Circuit External Circuitry
(a) Crystal/ceramic oscillation
(b) External clock
µPD75402A
X1
VDD
External
Clock
µPD75402A
VDD
X1
X2
X2
Crystal Resonator
or Ceramic Oscillator
(Standard 4.194304 MHz)
Note 1. When an external clock is input, STOP mode cannot be set. If STOP mode is set, the X1 pin is shorted
to VSS (GND potential) internally to suppress clock oscillation circuit leakage.
2. When using the system clock generation circuit the area enclosed in dotted line in Fig. 5-12 should be
wired in order to avoid effects of wiring capacitance etc., as shown below.
• Minimize the length of wiring
• Do not cross other signal lines, or position wiring close to a variable high current.
• The connecting point of the oscillator capacitor should always be of the same potential as VDD. Do
not connect it to the supply pattern where there is a high current.
• Do not pick up the signal from the oscillator.
Fig. 5-13 Example of Poor Resonator Connection Circuit (1/2)
(a) Long connection circuit wiring
(b) Crossed signal lines
PORTn
VDD
µPD75402A
n = 0,1,2,3,5,6,
µPD75402A
VDD
VDD
VDD
X1
X2
X1
X2
57
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Fig. 5-13 Example of Poor Resonator Connection Circuit (2/2)
(c) Signal line close to varyin high current
(d) Current flows an oscillator power supply line.
(potentials at A, B and C fluctuate.)
VDD
µPD75402A
VDD
µPD75402A
VDD
VDD
A
PORTn
X1
X2
X1
X2
High
current
C
B
(e) Signal is picked up.
µPD75402A
VDD
X1
X2
58
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.2.3 CPU Clock Setting
The CPU clock Φ is the clock supplied to the µPD75402A’s internal CPU, and the reciprocal of this clock is the
minimum instruction execution time (defined in this manual as 1 machine cycle).
On the µPD75402A, Φ can be switched in 3 steps by setting the PCC. In other words, with the same system clock
oscillator frequency fXX, the minimum instruction execution time can be changed in 3 steps. By using this function
to select operation at high speed (0.95 µs: When operating at 4.19 MHz) when the power supply voltage is 5 V and
low-speed operation (15.3 µs: When operating at 4.19 MHz) in backup mode, applications can be implemented in
which reduced current consumption and low-power operation is possible, which is an extremely useful facility.
Fig. 5-14 Use of Variable Minimum Instruction Execution Time Function
5V
Supply Voltage
3V
0.95 µs
15.3 µs
0.95 µs
Minimum Instruction
Execution Time
(4.19 MHz Operation)
Note As explained in the previous section, Φ is changed by a 4-bit memory handling instruction, but after a PCC
change, operation is at the pre-change Φ rate for the number of machine cycles shown in Table 5-5.
Example
;
;
Assume PCC = 0011.
MOV
MOV
BR
A, #0000
0.95 µs/4.19 MHz
PCC, A
PCC ← 0000
16 machine cycles
15.3 µs/4.19 MHz
59
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
As the PCC is set in 0 by RESET input, Φ is reset-started at the slowest speed (state in which the operating voltage
range is wide). For this reason, in a system with a slow supply voltage rise (such as a system with a high- capacitance
capacitor connected), correct operation is possible even when an adequate supply voltage cannot be attained after
a power-on reset.
Fig. 5-15 Change of Φ after Power-On Reset
5V
Supply
Voltage
0V
RESET Input Signal
Φ
Progran
Start
Change (By Program)
CPU
Operation
Oscillator
Stabilization
Time
Low-Speed
Operation
High-Speed
Operation
Table 5-5 Maximum Time Required for Change of CPU Clock
Max. Time Required for Change of
Max. No. of Machine Cycles
Required for Change of Φ
PCC Before Change
0000
PCC After Change
Φ * (When fXX = 4.19 MHz)
0010
0011
0000
0011
0000
0010
1
1
8
0010
0011
15.3 µs
8
16
16
*
When standby mode is not set until Φ changes.
60
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.2.4 Differences Between µPD75402A and µPD75402
Part of the clock generation circuit differs between the µPD75402A and the µPD75402.
The µPD75402 does not include the sections enclosed in dotted lines.
Fig. 5-16 Clock Generation Circuit - Differences between µPD75402A and µPD75402
• Basic Interva Timer (BT)
• Clock Output Circuit
• Serial Interface
• INT0 Noise Eliminator
• Clock Output Circuit
X1
VDD
System
Clock
Oscillation
Circuit
1/16 to 1/512
fXX or fX
Frequency Divider
1/2 1/6
X2
STOP
Oscillation
Frequency
Divider
Φ
1/4
• CPU
• INT0 Noise
Eliminator
• Clock Output
Circuit
PCC
0
PCC1
PCC2
4
HALT F/F
S
HALT*
PCC3
STOP*
R
Q
Clear
all bits
RESET Input Rising Edge
Detection Signal
STOP F/F
Clear
PCC2
Q
S
RESET Input Falling Edga
Detection Signal
R
Standby Release Signal from
Interrupt Control Circuit
*
Instruction execution
Remarks 1. fXX = System clock frequency
2. fX = external clock frequency
3. PCC: Processor clock control register
4. 1 clock cycle (tCY) of Φ is 1 machine cycle of an instruction.
61
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Next, the processor clock control register (PCC) of the µPD75402 is shown below. Setting of bit 1 of the PCC is
performed by a 4-bit memory handling instruction. At this time, ensure that bits 3, 2 and 0 are reset to “0” so that
the pattern “00 × 0” is written.
Fig. 5-17 µPD75402 Processor Clock Control Register Format
Address
FB3H
3
2
1
0
0
Symbol
PCC
PCC3 PCC2 PCC1
CPU clock selection bits when fXX ≤ 4.19 MHz
(
) : When fXX = 4.19 MHz
CPU Clock Frequency
Φ Output = fXX/64 (65.5 kHz)
Φ = fXX/8 (524 kHz)
1 Machine Cycle
15.3 µs
0
1
19.1 µs
When 4.19 MHz < fXX ≤ 5.0 MHz
(
) : When fXX = 4.91 MHz
CPU Clock Frequency
Φ Output = fXX/64 (76.7 kHz)
Φ = fXX/8 (614 kHz)
1 Machine Cycle
13 µs
0
1
1.63 µs
fXX : Main system clock oscillation circuit output frequency
CPU operating mode control bit
0
0
1
1
0
1
0
1
Normal operating mode
HALT mode
STOP mode
Setting prohibited
Note 1. Ensure that 0 is always written to PCC bit 0.
2. Unlike the µPD75402A, in the µPD75402, switching Φ is 2-step rather than 3-step. High-speed mode (0.95
µs at 4.19 MHz) cannot be specified.
62
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.3 CLOCK OUTPUT CIRCUIT
The clock output circuit outputs clock pulses from the P22/PCL pin, and is used to supply clock pulses to peripheral
LSIs, etc.
5.3.1 Clock Output Circuit Configuration
The configuration of the clock output circuit is shown in Fig. 5-18.
Fig. 5-18 Clock Output Circuit Configuration
From Clock
Generation
Circuit
Output
Buffer
Φ
Selector
fXX/26
P22/PCL
PORT2.2
P22
Output
Latch
PMGB Bit 2
Port 2 Input/
Output Mode
Specification Bit
CLOM3
0
CLOM1 CLOM0 CLOM
4
Internal Bus
Remarks When switching between clock output enabled/disabled states, consideration has been given to ensuring
that a short pulse is not output.
63
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.3.2 Clock Output Mode Register (CLOM)
CLOM is a 4-bit register used to control clock output.
CLOM is set by a 4-bit memory handling instruction. Bit handling instructions cannot be used. Also, this register
cannot be read.
RESET input clears CLOM to zero and selects the clock output disabled state.
Fig. 5-19 Clock Output Mode Register Format
Address
FD0H CLOM3
3
2
0
1
0
Symbol
CLOM
CLOM1 CLOM0
Clock output frequency selection bits ( ) : When fXX = 4.19 MHz
0
0
1
1
0
1
0
1
Φ output* (1.05 MHz, 524 kHz, 65.5 kHz)
Setting prohibited
fXX/26 output (65.5 kHz)
* Φ is the CPU clock selected by PCC
Clock output enable/disable bit
0
0
Output disabled
Output enabled
Note Ensure that 0 is written to bit 2 of CLOM.
64
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.3.3 Clock Output Procedure
Clock pulse output is performed by the following procedure.
(i) Set the clock output mode register.
(ii) Write 0 to the P22 output latch.
(iii) Set the port 2 input/output mode to output.
This procedure may be reversed depending on the treatment of P22/PCL prior to clock output.
Example 1. To output a 65.5 kHz (at 4.19 MHz operation) clock from the PCL/P22 pin. (The PCL/P22 pin outputs
the clock from the high-impedance state.)
MOV
MOV
CLR1
MOV
MOV
A, #1011B
CLOM, A
PORT2.2
; CLOM = 1011B
; P22 ← 0
XA, #04H
PMGB, XA
; PMGB = 00000100B
2. To output Φ . (The PCL/P22 pin outputs the clock from the low-impedance state.)
MOV
OUT
MOV
MOV
MOV
MOV
A, #0
PORT2, A
XA, #04H
PMGB, XA
A, #1000B
CLOM, A
; P22 ← 0
; CLOM ← 1000B
5.3.4 Examle of Remote Control Application
The µPD75402A clock output functions can be used in remote control applications. The remote control output
carrier frequency is selected by the clock frequency selection bits of the clock output mode register. Pulse output
enabling/disabling is performed by software control of the enable/disable bit.
When switching between clock output enabled/disabled states, consideration has been given to ensuring that
a short pulse is not output.
Fig. 5-20 Example of Remote Control Application
CLOM.3
PCL Pin
Output
65
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.4 BASIC INTERVAL TIMER
The µPD75402A is equipped with an 8-bit basic interval timer which has the following functions:
(a) Standard time generation (2 different time intervals)
(b) Reading counter contents
This basic interval timer can also be used as a watchdog timer for the detection of inadvertent program looping.
5.4.1 Basic Interval Timer Configuration
The configuration of the basic interval timer is shown in Fig. 5-21.
Fig. 5-21 Basic Interval Timer Configuration
Clear
Clear
From Clock
Generation
Circuit
fxx/25
Basic Interval Timer
( 8-Bit Frequency Divider)
Set
Bt
Interrupt
Request
Flag
MPX
Vectored
Interrupt
Request
Signal
fxx/29
IRQBT
BT
BTM3
BTM2
1
1
BTM
8
4
SET1*
Internal Bus
*
Instruction execution
66
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.4.2 Basic Intercal Timer Mode Register (BTM)
BTM is a 4-bit register which controls the operation of the basic interval timer.
BTM is set by a 4-bit memory handling instruction. Bit operations are not possible.
Example To set the interrupt generation interval to 1.95 ms (4.19 MHz).
MOV
MOV
A, #1111B
BTM. A
; BTM ← 1111B
When bit 3 is set (1), the contents of the basic interval timer are cleared and at the same time the basic interval
timer interrupt request flag (IRQBT) is also cleared (start of basic interval timer).
With a RESET input, BTM contents are cleared to zero and the interrupt request signal generation interval is set
to the maximum length.
Fig. 5-22 Basic Interval Timer Mode Register Format
3
2
1
1
0
1
Symbol
BTM
Address
F85H BTM3 BTM3
Interrupt Interval
Input Clock Specification
Wait Time when Standby )
( Mode is Released)
0
1
fXX/29 (8.18 kHz)
fXX/25 (131 kHz)
217/fXX (31.3 ms)
213/fXX (19.5 ms)
(
) : Values when fXX = 4.19 MHz
Basic interval timer start control bit
Basic interval timer is started by writeng “1”* (counter
and interrupt request flay are interrupt request flag are
cleared). Automaticallyreset(0)whenoperationisstarted.
* Ensure that the write is performed by a 4-bit write instruction.
Note Ensure that 1 is written to bits 1 and 0.
67
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.4.3 Basic Interval Timer Operation
The basic interval timer (BT) is constantly incremented by the clock from the clock generation circuit, and sets
the interrupt request flag (IRQBT) when it overflows. The BT count operation cannot be stopped.
Either of two times can be selected as the interrupt generation interval by setting the BTM (Fig. 5-22).
The basic interval timer and the interrupt request flag can be cleared by setting (1) bit 3 of BTM (directive to start
as interval timer).
The basic interval timer (BT) count status can be read by an 8-bit handling instruction. Data cannot be written
to the timer.
Note When the basic interval timer contents are read, it may happen that unstable data in the process of count
updating is read. To prevent this, the read instruction should be executed twice, then the two read contents
should be compared. If a comparison of the two read contents shows appropriate values, the latter contents
are taken as the result of the read. If the values are completely different, the operation should be repeated
from the beginning.
Example To read the BT count contents
MOV
LOOP: MOV
MOV
HL, #TEMP
XA, BT
TEMP, XA
XA, BT
A, @HL
LOOP
; Set table address to HL
; First read
; Save read value
MOV
; Second read
SKE
; Comparison of low-order 4 bits
BR
INCS
L
XCH
A, X
SKE
A, @HL
LOOP
; Comparison of high- order 4 bits
BR
68
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.4.4 Examples of Basic Interval Timer Applications
Example 1. In this example the basic interval timer is enabled, and the interrupt generation interval is set to 1.95
ms (at 4.19 MHz operation).
SEL
MOV
MOV
EI
MB15
A, #1111B
BTM,A
; Setting and start
; Enable interrupts
; Enable BT interrupts
EI
IEBT
Example 2. Example of watchdog timer application
When used as a watchdog timer, the basic interval timer’s function of generating an interrupt (INTBT)
at set intervals is used.
First, the standard time generated by the basic interval timer is decided.
Next, the program is divided into a number of modules whose processing should terminate within
the standard time, and the counter (BT) and interrupt request flag (IRQBT) are cleared each time a
module ends. A program is written such that an interrupt (INTBT) is not generated if operation is
normal. In other words, if an interrupt is generated, this is interpreted as indicating inadvertent
program looping.
The interrupt generation interval is set to 31.25 ms (in 4.19 MHz operation) so that the processing
time for each module is less than 31.25 ms.
SEL
MOV
MOV
EI
MB15
; or CLR1 MBE
A, #1011B
BTM, A
Initial
; Interval setting and counter start
Setting
EI
IEBT
Module 1
Processing termination within 31.25 ms
MOV A, #1011B
MOV BTM, A
Module 2
Processing termination within 31.25 ms
MOV A, #1011B
MOV BTM, A
69
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.5 SERIAL INTERFACE
5.5.1 Serial Interface Functions
The µPD75402A incorporates a clocked 8-bit serial interface, with the following three modes available.
(1) Operation-halted mode
This mode is used when no serial transfer is to be performed, and allows power dissipation to be reduced.
(2) 3-wire serial I/O mode
In this mode, 8-bit data transfer is performed using three lines: The serial clock (SCK), serial output (SO), and
serial input (SI).
In the 3-wire serial I/O mode simultaneous transmission and reception is possible, increasing the data transfer
processing speed.
The 3-wire serial I/O mode allows connection to 75X series and 78K series devices and various peripheral I/O
devices.
Serial data transfer is performed MSB-first.
70
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(3) SBI mode (serial bus interface mode)
In the SBI mode, communication is performed with multiple devices by means of two lines: The serial clock (SCK)
and the serial data bus (SB0).
This mode conforms to the NEC serial bus format.
In the SBI mode, the sender can output to the serial data bus an address to select the target device for serial
communication, a command which gives a directive to the target device, and actual data. The receiver can determine
by hardware whether the received data is an address, command or actual data.
Fig. 5-23 Example of SBI System Configuration
VDD
Slave CPU
Master CPU
Serial Clock
SCK
SB0
SCK
SB0
Address 1
#1
Address
Command
Data
Slave IC
SCK
SB0
Address N
#N
Note When the µPD75402A is used as a slave CPU, its address is limited to the range C0H to C7H.
5.5.2 Serial Interface Configuration
The serial interface block diagram is shown in Fig. 5-24.
71
Fig. 5-24 Serial Interface Block Diagram
Internal Bus
Bit
Test
Bit
Bit Test
8
8
8
Manipulation
Slave Address
Register (SVA)
CSIM
SBIC
(8)
Match
Signal
RELT
Address Comparator
CMDT
(8)
P03/SI
SO
Latch
SET CLR
Shift Registe (SIO)r
D
Q
(8)
P02/SO/SB0
Busy/Ac-
Knowledge
Output
Circuit
RELD
CMDD
ACKD
Bus Release/
Command/Ac-
Knowledge
Detection
Circuit
P01/SCK
INTCSI
Control
Circuit
INTCSI
(IRQCSI
Signal
Serial Clock
Copunter
Setting)
fxx/24
Serial Clock
Control
Cirucit
Serial
Clock
Selector
External
SCK
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(1) Serial operating mode register (CSIM)
CSIM is an 8-bit register which specifies the serial interface operating mode, serial clock, wake-up function, etc.
(See 5.5.3 (1) “Serial operating mode register” for details.)
(2) Serial bus interface control register (SBIC)
SBIC is an 8-bit register composed of bits which control the serial bus and flags which indicate various statuses
of the input data from the serial bus, and is mainly used in the SBI mode. (See 5.5.3 (2) “Serial bus interface control
register” for details.)
(3) Shift register (SIO)
The SIO register converts 8-bit serial data to parallel data and 8-bit parallel data to serial data. It performs
transmission/reception operations (shift operations) in synchronization with the serial clock. A serial transfer is
started by writing data to SIO. Actual transmission/reception operations are controlled by writes to the SIO. (See
5.5.3 (3) “Shift register” for details).
(4) SO latch
A latch which holds the SO/SB0 and SI pin levels. Can be directly controlled by software. Set at the end of the
8th SCK pulse in the SBI mode. (See 5.5.3 (2) “Serial bus interface control register” for details.)
(5) Serial clock selector
Selects the serial clock to be used.
(6) Serial clock counter
Counts the serial clock cycles output and input in a transmission/reception operation, and checks that 8-bit data
transmission/reception has been performed.
(7) Slave address register (SVA), address comparator
In SBI mode, this register is used when the µPD75402A is used as a slave device. The slave sets its own
specification number (slave address value) in the SVA register. The master outputs a slave address to select a
specific slave.
The address comparator is used to compare the slave address received from the master with the SVA value: If
they match the relevant slave is determined to have been selected. (See5.5.3 (4) “Slave address register”for details.)
73
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(8) INTCSI control circuit
Controls the generation of interrupt requests. In the following case, the interrupt requests (INTCSI) are generated
and interrupt request flags (IRQCSI) are set (see Fig. 6-1 “Interrupt Control Circuit Block Diagram”).
• In 3-wire serial I/O mode
An interrupt request is generated on each count of 8 serial clock cycles.
• In SBI mode
…
When WUP* = “0”
An interrupt request is generated on each count of 8 serial clock cycles.
An interrupt request is generated when the SVA and SIO values match after address
reception.
…
When WUP = “1”
*
WUP: Wake-up function specified bit (bit 5 of CSIM)
(9) Serial clock control circuit
Controls the supply of the serial clock to the shift register. Also controls the clock output to the SCK pin when
the internal system clock is used.
(10) Busy/acknowledge output circuit, bus release/command acknowledge detection circuit
These circuits perform output and detection of various control signals in the SBI mode.
They do not operate in the 3-wire serial I/O mode.
5.5.3 Register Functions
(1) Serial operating mode register (CSIM)
The format of the serial operating mode register (CSIM) is shown in Fig. 5-25.
CSIM is an 8-bit register which specifies the serial interface operating mode, serial clock, wake-up function, etc.
CSIM is manipulated by 8-bit memory manipulation instructions. The high-order 3 bits can be manipulated bit
by bit using the individual bit names.
Read/write capability differs from bit to bit (see Fig. 5-25). Bit 6 can be tested only, and data written to this bit
is invalid.
Reset input clears this register to 00H.
74
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Fig. 5-25 Serial Operating Mode Register (CSIM) Format (1/2)
Address
FE0H
7
6
5
4
0
3
2
0
1
0
0
Symbol
CSIM
CSIE
COI
WUP
CSIM3
CSIM1
Serial Clock Selection Bit (W)
Serial Interface Operating Mode Selection Bit (W)
Wake-up Function Specification Bit (W)
Signal from Address Comparator (R)
Serial Interface Operation Enable/Disable Specification Bit (W)
Remarks (R) Read only
(W) Write only
Note 0 must be written to CSIM bits 4, 2, 0.
Serial clock selection bit (W)
Serial Clock
CSIM1
SCK Pin Mode
3-Wire Serial I/O Mode
SBI Mode
0
1
Input clock to SCK pin from off chip
fXX/24 (262 kHz)
Input
Output
Remarks
(
) When fXX = 4.19 MHz
Serial interface operating mode selection bit (W)
Shift Register
Bit Order
CSIM3
0
Operating Mode
SO Pin Function
SI Pin Function
SIO 7 to 0 ↔ XA
(MBS-first transfer)
SI/P03
(Input)
3-wire serial
I/O mode
SO/P02
(CMOS output)
SB0/P02
(N-ch open-drain
input/output)
SIO 7 to 0 ↔ XA
(MBS-first transfer)
P03 input
1
SBI mode
75
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Fig. 5-25 Serial Operating Mode Register (CSIM) Format (2/2)
Wake-up function specification bit (W)
0
IRQCSI set at end of every serial transfer in each mode.
WUP
Used only in SBI mode. IRQCSI is set only when the address received after bus
release matches the slave address register data (wake-up status). SB0 is high
impedance.
1
Note If WUP = 1 is set during BUSY signal output, BUSY is not released. With the SBI, the BUSY signal is output
after the BUSY release directive until the next fall of the serial clock (SCK). When setting WUP = 1, it is
necessary to confirm that the SB0 pin has been driven high after BUSY is released before setting WUP =
1.
Signal from address comparator (R)
Clearing Condition (COI = 0)
Setting Condition (COI = 1)
COI*
When slave address register (SVA) and
shift register data do not match
When slave address register (SVA) and shift
register data match.
*
A COI read is valid only before the start or after completion of a serial transfer. During a transfer an indeterminate
value will be read. Also, COI data written by an 8-bit manipulation instruction is ignored.
Serial interface operation enable/disable specification bit (W)
Shift Register
Operation
Serial Clock
Counter
IRQCSI Flag
Retained
SO/SB0 & SI Pins
Shift operation
disabled
0
1
Cleared
Port 0 function only
CSIE
Function in each
mode plus port 0
function
Shift operation
enabled
Count operation
Settable
76
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Remarks 1. The operating mode can be selected according to the setting of CSIE and CSIM3.
CSIE
CSIM3
Operating Mode
Operation-halted mode
0
1
1
×
0
1
3-wire serial I/O mode
SBI mode
2. The P10/SCK pin status depends on the setting of CSIE and CSIM0 as shown below.
CSIE
CSIM1
P10/SCK Pin Status
0
0
1
1
0
1
0
1
Input port
High-level output
Serial clock input (high impedance)
Serial clock output (high-level output)
3. The following procedure should be used to clear CSIE during a serial transfer.
➀ Clear the interrupt enable flag to set the interrupt disabled state.
➁ Clear CSIE.
➂ Clear the interrupt request flag.
Example 1. This example selects fXX/24 as the serial clock, generates an IRQCSI serial interrupt at the end of each
serial transfer, and selects the mode in which serial transfers are performed in the SBI mode with
the SB0 pin as the serial data bus.
MOV
MOV
XA, #10001010B
CSIM, XA
; CSIM ← 10001010B
2. To enable serial transfers in accordance with the contents of CSIM.
SET1 CSIE
77
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(2) Serial bus interface control register (SBIC)
The format of the serial bus interface control register (SBIC) is shown in Fig. 5-26.
SBIC is an 8-bit register composed of bits which control the serial bus and flags which indicate various statuses
of the input data from the serial bus, and is mainly used in the SBI mode.
SBIC is manipulated by bit-manipulation instructions; it cannot be manipulated by 4-bit or 8-bit memory
manipulation instructions.
Read/write capability differs from bit to bit (see Fig. 5-26).
Reset input clears this register to 00H.
Note In the 3-wire serial I/O mode, only the following bits can be used:
…
• Bus release trigger bit (RELT)
• Command trigger bit (CMDT)
SO latch setting
SO latch clearing
…
Fig. 5-26 Serial Bus Interface Control Register (SBIC) Format (1/3)
Address
FE2H
7
6
5
4
3
2
1
0
Symbol
SBIC
BSYE
ACKD
ACKE
ACKT
CMDD
RELD
CMDT
RELT
Bus Release Trigger Bit (W)
Command Trigger Bit (W)
Bus Release Datection Flag (R)
Command Detection Flag (R)
Acknowledge Trigger Bit (W)
Acknowledge Enable Bit (R/W)
Acknowledge Detection Flag (R)
Busy Enable Bit (R/W)
Remarks (R)
Read only
(W) Write only
(R/W) Read/write enabled
78
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Fig. 5-26 Serial Bus Interface Control Register (SBIC) Format (2/3)
Bus release trigger bit (W)
The bus release signal (REL) trigger output control bit. The SO latch is set (1) by setting this
bit (RELT = 1), after which the RELT bit is automatically cleared (0).
RELT
Note SB0 must not be cleared during a serial transfer: Ensure that it is cleared before a transfer is started or after
it is completed.
Command trigger bit (W)
The command signal (CMD) trigger output control bit. The SO latch is cleared (0) by setting
this bit (CMDT = 1), after which the CMDT bit is automatically cleared (0).
CMDT
Note SB0 must not be cleared during a serial transfer: Ensure that it is cleared before a transfer is started or after
it is completed.
Bus release detection flag (R)
Clearing Conditions (RELD = 0)
Setting Condition (RELD = 1)
➀ When a transfer start instruction is
executed
➁ When RESET is input
➂ When CSIE = 0 (See Fig. 5-25)
RELD
When the bus release signal (REL) is de-
tected
When SVA and SIO do not match
4
when an address is received
Command detection flag (R)
Clearing Conditions (CMDD = 0)
Setting Condition (CMDD = 1)
➀ When a transfer start instruction is
executed
➁ When tje bus release signal (REL) is
detected
CMDD
When the command signal (CMD) is de-
tected
➂ When RESET is input
When CSIE = 0 (See Fig. 5-25)
4
Acknowledge trigger bit (W)
When ACKT is set after the end of a transfer, ACK is output in synchronization with the next
SCK. After th ACK signal is output, ACKT is automatically cleared (0).
ACKT
Note 1. ACKT must not be set (1) before completion of a serial tramsfer or during a
transfer.
2. ACKT cannot be clearedby software.
3. When ACKT is set, ACKE should be reset to 0.
79
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Fig. 5-26 Serial Bus Interface Control Register (SBIC) Format (3/3)
Acknowledge enable bit (R/W)
Disables automatic output of the acknowledge signal (ACK) (outpt by ACKT is
possibel).
0
1
ACK is output is synchronization with the 9th
When set before end of transfer
ACKE
SCK clock cycle.
ACK is output in synchronization with SCK
immediately after execution of the setting
instruction.
When set after end of transfer
Acknowledge detection flag (R)
Clearing Conditions (ACKD = 0)
Setting Condition (ACKD = 1)
ACKD
➀ When a transfer is started
➁ When RESET is input
When the acknowledge signal (ACK) is de-
tected (Synchronized with rise of SCK)
Busy enable bit (R/W)
➀ Disablin of automatic busy signal output
0
➁ Busy signal output is stopped in synchronization with the fall of SCK immediately
after execution ofthe clearing instruction.
BSYE
The busy signal is output in synchronization with the fall or SCK following the
acknowledge signal.
1
Example 1. To output the command signal.
SET1 CMDT
2. To test RELD and CMDD, and perform different processing according to the type of receive data.
This interrupt routine is only performed when WUP = 1 and there is an address match.
SKF
BR
RELD
!ADRS
CMDD
;
;
Test RELD
SKT
BR
Test CMDD
!DATA
...............
CMD
:
;
;
;
Command interpretation
Data processing
DATA : ...............
ADRS : ...............
Address decoding
80
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(3) Shift register (SIO)
The configuration around the shift register is shown in Fig. 5-27. SIO is an 8-bit register which carries out parallel-
to-serial conversion and performs serial transmission/reception (shift operations) in synchronization with the serial
clock.
A serial transfer is started by writing data to SIO.
In transmission, the data written to SIO is output to the serial output (SO) or the serial data bus (SB0). In reception,
data is read into SIO from the serial input (SI) or SB0.
SIO can be read or written to by an 8-bit manipulation instruction.
If RESET is input during its operation, the value of SIO is indeterminate. If RESET is input in the standby mode,
the value of SIO is retained.
The shift operation stops after transmission/reception of 8 bits.
Fig. 5-27 Configuration Around Shift Register
RELT
Address
Comparator
Internal Bus
CMDT
SET
CLR
Shift Register
(SIO)
SO Latch
P02/SO
/SB0
D
Q
CLK
BUSY/ACK
Shift Clock
N-ch Open-Drain Output
SIO reading and the start of a serial transfer (write) are possible at the following times:
• When the serial interface operation enable/disable bit (CSIE) = 1, except when CSIE is set to “1” after data has
been written into the shift register.
• When the serial clock has been masked agter an 8-bit serial transfer.
• When SCK is high.
Ensure that SCK is high when data is written to or read from the SIO register.
In the SBI mode data bus configuration, input pins and output pins have dual functions. Output pins have an N-
ch open-drain configuration. Therefore, in a device in which reception is about to be performed, FFH should be set
in the SIO register.
81
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(4) Slave address register (SVA)
SVA is an 8-bit register used by the slave to set the slave address value (its own specification number).
SVA is a write-only register which is manipulated by 8-bit manipulation instructions.
After RESET signal input, the value of SVA is indeterminate. However, when RESET is input in the standby mode,
the value of SVA is retained.
In the SBI mode, the slave address register (SVA) has the following two functions:
(a) Slave address detection
Used when the µPD75402A is connected to the serial bus as a slave device.
The high-order 5 bits of the SVA register are fixed at 11000 by hardware. Therefore, the address assigned
to the µPD75402A is limited to the range C0H to C7H.
The master outputs to its connected slaves a slave address to select a specific slave. If these two data items
(the slave address output from the master and the SVA value) are found to match when compared by the
address comparator, the relevant slave is determined to have been selected.
At this time, bit 6 (COI) of the serial operating mode register (CSIM) is set to “1”.
When an address is received the bus release detection flag (RELD) is cleared (0) if a match is not detected.
IRQCSI is set only when a match is detected when WUP = 1. This interrupt request indicates that a
communication request has been issued from the master to the µPD75402A.
(b) Error detection
The SVA performs error detection in the following cases:
• When the µPD75402A transmits addresses, commands or data as the master device.
• When the µPD75402A transmits data as a slave device.
See 5.5.6 (8) “Error detection” for details.
Note When data is written to SVA, ensure that a value between C0H and C7H is written.
82
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.5.4 Operation-Halted Mode
The operation-halted mode is used when no serial transfer is performed, allowing power dissipation to be
reduced.
In this mode, the shift register does not perform shift operations and can be used as an ordinary 8-bit register.
When the RESET signal is input the operation-halted mode is set. The P02/SO/SB0 and P03/SI pins are fixed as
input ports. P01/SCK can be used as an input port depending on the setting of the serial operating mode register.
(1) Register setting
Operation-halted mode setting is performed by the serial operating mode register (CSIM) (see 5.5.3 (1)“Serial
operating mode register” for full details of CSIM).
CSIM is manipulated by 8-bit memory manipulation instructions, but bit manipulation of CSIE is also possible.
Manipulation is also possible using bit names.
Reset input clears this register to 00H.
The shaded area indicates bits used in the operation-halted mode.
Address
FE0H
7
6
5
4
0
3
2
0
1
0
0
Symbol
CSIM
CSIE
C0I
WUP
CSIM3
CSIM1
Serial Clock Celection Bit (W)*
Serial Interface Operating Mode Selection Bit (W)
Wake-up Function Specification Bit (w)
Match Signal from Address Comparator (R)
Serial Interface Operation Enable/Disable Specification Bit (W)
*
Allow selection of P01/SCK pin status.
Remarks (R)
Read only
(W) Write only
Serial interface operation enable/disable specification bit (W)
Serial Clock
Counter
Shift Register
Operation
IRQCSI Flag
Retained
SO/SB0 & SI Pins
Shift operation
disabled
Cleared
Port o function only
0
CSIE
83
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Serial clock selection bit (W)
The P01/SCK pin status depends on the CSIM1 setting as shown below.
CSIM1
P01/SCK Pin Status
High impedance
High level
0
1
The following procedure should be used to clear CSIE during a serial transfer.
➀ Clear the interrupt enable flag (IECSI) to set the interrupt disabled state.
➁ Clear CSIE.
➂ Clear the interrupt request flag (IRQCSI).
5.5.5 3-Wire Serial I/O Mode Operation
The 3-wire serial I/O mode allows connection to the system used in the 75X series, µPD7500 series, 87AD series,
etc.
Communication is performed using three lines: The serial clock (SCK), serial output (SO), and serial input (SI).
Fig. 5-28 Example of 3-Wire Serial I/O System Configuration
3-wire serial I/O ↔ 3-wire serial I/O
Master CPU
Slave CPU
➤
➤
SCK
SCK
SO
SI
SI
➤
SO
(1) Register setting
When the device is used in the 3-wire serial I/O mode, setting can be performed by means of the following two
registers:
• Serial operating mode register (CSIM)
• Serial bus interface control register (SBIC)
84
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(a) Serial operating mode register (CSIM)
When the 3-wire serial I/O mode is used, CSIM is set as shown below (see 5.5.3 (1) “Serial operating mode
register” for full details of CSIM).
CSIM is manipulated by 8-bit memory manipulation instructions. Bit manipulation of bits 7, 6 and 5 is also
possible.
Reset input clears the CSIM register to 00H.
The shaded area indicates bits used in the 3-wire serial I/O mode.
Address
FE0H
7
6
5
4
0
3
2
0
1
0
0
Symbol
CSIM
CSIE
C0I
WUP
CSIM3
CSIM1
Serial Clock Selection Bit (W)
Serial Interface Operating Mode Selection Bit (W)
Wake-up Function Specification Bit (w)
Match Signal from Address Comparator (R)
Serial Interface Operation Enable/Disable Specification Bit (W)
Remarks (R)
Read only
(W) Write only
Serial clock selection bit (W)
Serial Clock
CSIM1
SCK Pin Mode
3-Wire Serial I/O Mode
SBI Mode
0
1
Input clock to SCK pin from off chip
fXX/24 (262 kHz)
Input
Output
Remarks Figuer in ( ) apply to fXX = 4.19 MHz operation
Serial interface operating mode selection bit (W)
CSIM3
0
Operating Mode
Shift Register Bit Order
SO Pin Function
Si Pin Function
3-wire serial I/O
mode
SIO 7 to 0 ↔ XA
(MSB-fist transfer)
SO/P02
(CMOS Output)
SI/P03 (Input)
Wake-up function specification bit (W)
WUP
0
IRQCSI set at end of every serial transfer.
85
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Signal from address comparator (R)
Clearing Conditions (COI = 0)
Setting Condition (COI = 1)
COI*
When slave address register (SVA) and
shift register data do not match.
When slave address register (SVA) and shift
register data match.
*
A CIO read is valid only before the start of after completion of a serial transfer. During a transfer an indeterminate
value will be read.
Also, COI data written by an 8-bit manipulation instruction is ignored.
Serial interface operation enable/disable specification bit (W)
Shift Register
Operation
Serial Clock
Counter
IRQCSI Flag
Settable
SO/SB0 & SI Pins
Function in each
mode plus port 0
function
Shift operation
enabled
Count operation
1
CSIE
86
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(b) Serial bus interface control register (SBIC)
When the 3-wire serial I/O mode is used, SBIC is set as shown below (see 5.5.3 (2) “Serial bus interface
control register” for full details of SBIC).
SBIC is manipulated by bit manipulation instructions.
Reset input clears the SBIC register to 00H.
The shaded area indicates bits used in the 3-wire serial I/O mode.
Address
FE2H
7
6
5
4
3
2
1
0
Symbol
SBIC
BSYE
ACKD
ACKE
ACKT
CMDD
RELD
CMDT
RELT
Bus Release Trigger Bit (W)
Should not used in 3-wire serial I/O mode
Command Trigger Bit (w)
Remarks (W) Write only
Bus release trigger bit (W)
The command signal (REL) trigger output control bit. The SO latch is cleared (0) by setting
this bit (RELT = 1), after which the RELT bit is automatically cleared (0).
RELT
Command trigger bit
The command signal (CMD) Trigger output control bit. The SO latch is cleared (0) by setting
this bit (CMDT = 1), after which the CMDT bit is automatically cleared (0).
CMDT
Note Bits other than RELT and CMDT should not be used in the 3-wire serial I/O mode.
87
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(2) Communication operation
In the 3-wire serial I/O mode, data transmission/ reception is performed in 8-bit units. Data is transmitted/received
bit by bit in synchronization with the serial clock.
Shift register shift operations are performed in synchronization with the fall of the serial clock (SCK). Then send
data is held in the SO latch output from the SO pin. Also, receive data input to the SI pin is latched in the shift register
on the rise of SCK.
At the end of an 8-bit transfer the operation of the shift register stops automatically and the IRQCSI interrupt
request flag is set.
Fig. 5-29 3-Wire Serial I/O Mode Timing
SCK
1
2
3
4
5
6
7
8
DI7
DI6
DI5
DI4
DI3
DI2
DI1
DI0
SI
SO
DO7
DO6
DO5
DO4
DO2
DO1
DO0
DO3
IRQCSI
End of
Transfer
Start of Transfer Symchronized with Fall of SCK
Execution of Instruction which Writes Data to SIO
(Trasfer Start Directive)
The SO pin becomes a CMOS output and outputs the SO latch status, and thus the SO pin output status can be
manipulated in accordance with the setting of the RELT bit and CMDT bit.
However, manipulation should not be performed during a serial transfer.
88
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(3) Serial clock selection
Serial clock selection is performed by setting bit 1 of the serial operating mode register (CSIM). Either of the
following clocks can be selected.
Table 5-6 Serial Clock Selection and Use (in 3-Wire Serial I/O Mode)
Mode
Register
Serial Clock
Possible Timing for Shift
Register R/W and Serial
Transfer Start
Use
Serial Clock
Masking
Source
CSIM 1
Automatically
masked at end of
8-bit data
Possible only when serial transfer
is halted* or when SCK is high.
External
SCK
Slave CPU
0
1
transfer.
Possible only when serial transfer
is halted* or when SCK is high.
Medium-speed
serial transfer
fXX/24
*
“When serial transfer is halted” means in the operation-halted mode, or when the serial clock is masked after
an 8-bit transfer.
(4) Signals
RELT and CMDT operation is shown in Fig. 5-30.
Fig. 5-30 RELT & CMDT Operation
SO
RELT
CMDT
89
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(5) Data transfer order
The µPD75402A 3-wire serial I/O mode differs from that of other 75X series products in that it is not possible to
switch between MSB and LSB as the first bit.
Serial transfer is performed MSB-first.
Fig. 5-31 Shift Register (SIO) and Internal Bus Configuration
7
6
Internal
Bus
1
0
Read/Write Gate
SO Latch
Shift Register (SIO)
SI
D
Q
SO
SCK
(6) Start of transfer
When the following two conditions are met a serial transfer is started by setting transfer data in the shift register
(SIO).
• The serial interface operation enable/disable bit (CSIE) = 1.
• After an 8-bit serial transfer, the internal serial clock is stopped or SCK is high.
Note
The transfer will not be started if CSIE is set to “1” after data is written into the shift register.
When an 8-bit transfer ends, the serial transfer stops automatically and the IRQCSI interrupt request flag is set.
Example In the following example the data in the RAM specified by the HL register is transferred to SIO, and at
the same time the SIO data is fetched into the accumulator and the serial transfer is started.
MOV
XCH
XA, @HL ; Fetch send data from RAM
XA, SIO ; Exchange send data with receive data and start transfer
90
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(7) 3-wire serial I/O mode applications
(a) To transfer data MSB-first (master operation) using a 262 kHz transfer clock (when operating at 4.19 MHz).
<Sample program>
MOV
MOV
MOV
MOV
XA, #10000010B
CSIM, XA
; Transfer mode setting
XA, TDATA
SIO, XA
; TDATA is transfer data storage address
; Transfer data setting & start of transfer
Note From the second time onward, the transfer can be started by setting data in SIO (MOV SIO, XA or XCH XA,
SIO).
µPD75402A
➤
SCK
SCK
SI
➤
SO/SB0
In this application the µPD75402A SI pin can be used as an input port.
91
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(b) To transmit/receive MSB-first data using an external clock (slave operation).
µPD75402A
Other Microcomputer
➤
➤
P01/SCK
SCK
SO
SI
SI
➤
SO/SB0
<Sample program>
Main routine
MOV
MOV
MOV
MOV
EI
XA, #80H
CSIM, XA
XA, TDATA
SIO, XA
; Serial operation stopped, external clock specification
; Transfer data setting & start of transfer
IECSI
EI
Interrupt routine
MOV
XCH
MOV
RETI
XA, TDATA
XA, SIO
; Receive data ÷ send data & start of transfer
RDATA, XA ; Receive data save
92
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
5.5.6 SBI Mode Operation
The SBI (serial bus interface) is a high-speed serial interface which conforms to the the NEC serial bus format.
The SBI is a single-master high-speed serial bus. Its format includes the addition of bus configuration functions
to the clocked serial I/O method to enable communication to be performed with multiple devices using two signal
lines. Consequently, when a serial bus is configured with multiple microcomputers and peripheral ICs, it is possible
to reduce the number of ports used and the amount of wiring on the substrate.
The master can output to a slave on the serial data bus an address to select the target device for serial
communication, a command which gives a directive to the target device, and actual data. The slave can determine
by hardware whether the received data is an address, command or actual data. This function allows the serial
interface control portion of the application program to be simplified.
SBI functions are incorporated in a number of devices including the 75X series, and 78K series 8-bit single-chip
microcomputers.
An example of a serial bus configuration when CPUs and peripheral ICs with a serial interface conforming to the
SBI are used is shown in Fig. 5-32.
In the SBI the SB0 serial data bus pin is an open-drain output and thus the serial data bus line is in the wired-
OR state. The serial data bus line requires a pull-up resistor.
Fig. 5-32 Example of SBI Serial Bus System Configuration
+ VDD
Seroal Data Bis
SB0
SCK
SB0
SCK
Slave CPU
Address 1
Master
CPU
Serial Clock
SB0
SCK
Slave CPU
Address 2
SB0
SCK
Slave IC
Address N
Note When master/slave exchange processing is performed, since serial clock line (SCK) input/output switching
is performed asynchronously between master and slave, a pull-up resistor is also required for the serial
clock line (SCK).
93
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(1) SBI functions
Since conventional serial I/O methods have only data transfer functions, when a serial bus is configured with
multiple devices connected a large number of ports and wires are required for Chip Select signal and command/
data differentiation, busy status recognition, etc. If these controls are performed by software, the load incurred by
software is very large.
When the SBI, a serial bus can be configured using only two lines: The serial clock, SCK, and the serial data bus,
SB0. As a result, the number of microcomputer ports and the amount of substrate wiring can be significantly
reduced.
SBI functions are described below.
(a) Address/command/data differentiation function
Identifies serial data as an address, command or actual data.
(b) Chip selection by address
The master performs chip selection by address transmission.
(c) Wake-up function
A slave can identify address reception (chip selection) easily by means of the wake-up function (settable/
releasable by software).
When the wake-up function is set, an interrupt (IRQCSI) is generated when a matching address is received.
As a result, non-selected CPUs can operate without regard to serial communications even when commu-
nication with multiple devices is performed.
(d) Acknowledge signal (ACK) control function
Controls the acknowledge signal used to confirm serial data reception.
(e) Busy signal (BUSY) control function
Controls the busy signal used to give notification of a slave busy status.
94
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(2) SBI definition
The SBI serial data format and the meaning of the signals used are explained in the following section. Serial data
transmitted via the SBI is classified into three types: Commands, addresses and data. Serial data forms a frame with
the configuration shown below.
Address, command and data transfer timing is shown in Fig. 5-33.
Fig. 5-33 SBI Transfer Timing
Address Transfer
8
9
SCK
SB0
BUSY
A7
A0
ACK
Bus Release
Signal
Command Transfer
Command Signal
SCK
9
SB0
C7
C0ACK
BUSY
READY
Data Transfer
8
9
SCK
SB0
ACK
D0
BUSY
READY
D7
The bus release signal and command signal are output by the master. The BUSY signal is output by the slave.
ACK can be output by either the master or slave (normally output by the 8-bit data receiver).
The serial clock is output by the master continuously from the start of an 8-bit data transfer until BUSY is released.
95
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(a) Bus release signal (REL)
The bus release signal indicates that the SB0 line has changed from low to high when the SCK line is high
(when the serial clock is not being output). This signal is output by the master.
Fig. 5-34 Bus Release Signal
SCK
SB0
“H”
The bus release signal indicates that the master is about to send an address to a slave. Slaves incorporate
hardware to detect the bus release signal.
(b) Command signal (CMD)
The command signal indicates that the SB0 line has changed from high to low when the SCK line is high
(when the serial clock is not being output). This signal is output by the master.
Fig. 5-35 Command Signal
SCK
SB0
“H”
Slave incorporate hardware to detect the command signal.
96
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(c) Address
An address is 8-bit data output by the master to slaves connected to the bus line in order to select a particular
slave.
Fig. 5-36 Address
1
2
3
4
5
6
7
8
SCK
SB0
A7
A6
A5
A4
A3
A2
A1
A0
Address
Bus Release Signal
Command Signal
The 8-bit data following the bus release signal and command signal is defined as an address. In a slave this
condition is detected by hardware and a check is performed by hardware to see if the 8-bit data matches the
slave’s own specification number (slave address). If the 8-bit data matches the slave address, that slave is
determined to have been selected and communication is subsequently performed with the master until a
disconnect directive is received from the master.
Fig. 5-37 Slave Selection by Address
Master
Slave 1
Slave 2
Slave 3
Slave 4
Not Selected
Selected
Sends Address
of Slave
Not Selected
Selected
97
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(d) Command & data
The master performs command transmission to or data transmission/reception to/from the slave selected
by address transmission.
Fig. 5-38 Command
1
2
3
4
5
6
7
8
SCK
SB0
C7
C6
C5
C4
C3
C2
C1
C0
Command Signal
Command
Fig. 5-39 Data
SCK
SB0
1
2
3
4
5
6
7
8
D7
D6
D5
D4
D3
D2
D1
D0
Data
The 8-bit data following the command signal is defined as a command. 8-bit data with no command signal
is defined as data. The way in which commands and data are used can be freely decided according to the
communication specifications.
98
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(e) Acknowledge signal (ACK)
The acknowledge signal is used to confirm serial data reception between the sender and receiver.
Fig. 5-40 Acknowledge Signal
[When output in synchronization with 11th SCK clock cycke]
SCK
SB0
8
9
10
11
ACK
[When output in synchronization with 9th SCK clock cycke]
SCK
SB0
8
9
ACK
The acknowledge signal is a one-shot pulse synchronized with the fall of SCK after an 8-bit data transfer.
Its position is arbitrary and it can be synchronized with any SCK clock cycle.
After 8-bit data transmission the sender checks whether the receiver has sent back an acknowledge signal.
If an acknowledge signal is not returned within a specific time after data transmission, reception can be judged
not to have been performed correctly.
99
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(f) Busy signal (BUSY), ready signal (READY)
The busy signal notifies the master that a slave is preparing for data transmission/reception.
The ready signal notifies the master that a slave is ready for data transmission/reception.
Fig. 5-41 Busy Signal & Ready Signal
SCK
8
9
SB0
ACK
BUSY
READY
With the SBI a slave reports its busy status to the master by driving the SB0 line low.
The busy signal is output following the acknowledge signal output by the master or slave. Busy signal
setting/release is performed in synchronization with the fall of SCK. When the busy signal is released the
master automatically terminates output of the SCK serial clock.
When the busy signal is released and the ready signal sate is entered the master can start the next transfer.
100
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(3) Register setting
When the device is used in the SBI mode, setting can be performed by means of the following two registers:
• Serial operating mode register (CSIM)
• Serial bus interface control register (SBIC)
(a) Serial operating mode register (CSIM)
When the SBI mode is used, CSIM is set as shown below (see 5.5.3 (1) “Serial operating mode register”
for full details of CSIM).
CSIM is manipulated by 8-bit manipulation instructions. Bit manipulation of bits 7, 6 and 5 is also possible.
Reset input clears the CSIM register to 00H.
The shaded area indicates bits used in the SBI mode.
Address
FE0H
7
6
5
4
0
3
2
0
1
0
0
Symbol
CSIM
CSIE
COI
WUP
CSIM3
CSIM1
Serial Clock Selection Bit (W)
Serial Interface Operating Mode Selection Bit (W)
Wake-up Functing Specification Bit (w)
Signal from Address Comparator (R)
Serial Interface Operation Enable/Disable Specification Bit (W)
Remarks (R)
Read only
(W) Write only
Serial clock selection bit (W)
Serial Clock
CSIM1
SCK Pin Mode
3-Wire Serial I/O Mode
Input clock to SCK pin from off chip
fXX/24 (262 kHz)
SBI Mode
0
1
Input
Output
Remarks Figure in ( ) apply to fXX = 4.19 MHz operation
Serial interface operating mode selection bit (W)
Shift Register
CSIM3
1
Operating Mode
SBI mode
SO Pin Function
SI Pin Function
P03 input
Bit Order
SB0/P02
(N-ch open-drain
input/output)
SIO 7 to 0 ↔ XA
(MBS-first transfer)
101
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Wake-up function specification bit (W)
IRQCSI set at end of every serial transfer in SBI mode mask state.
0
1
User only when functioning as a slave in SBI mode. IRQCSI is set only when the
address received after bus release matches the slace address register data (wake-up
status). SB0 is high impedance.
WUP
Note If WUP = 1 is set during BUSY signal output, BUSY is not released. With the SBI, the BUSY signal is output
after the BUSY release directive until the next fall of the serial clock (SCK). when setting WUP = 1, it is
necessary to confirm that the SB0 pin has been driven high after BUSY is released before setting WUP =
1.
Signal from address comparator (R)
Clearing Conditions (COI = 0)
Setting Condition (COI = 1)
COI*
When slave address register (SVA) and
shift register data do not match.
When slave address register (SVA) and shift
register data match.
*
A COI read is valid only before the start or after completion of a serial transfer. During a transfer an indeterminate
value will be read.
Also, COI data written by an 8-bit manipulation instruction is ignored.
Serial interface operation enable/disable specification bit (W)
Serial Clock
Counter
Shift Register
Operation
IRQCSI Flag
Settable
SO/SB0 & SI Pins
Function in each
mode plus port 0
function
Shift operation
enabled
Count operation
1
CSIE
102
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(b) Serial bus interface control register (SBIC)
When the SBI mode is used, SBIC is set as shown below (see 5.5.3 (2) “Serial bus interface control register”
for full details of SBIC).
SBIC is manipulated by bit manipulation instructions.
Reset input clears the SBIC register to 00H.
The shaded area indicates bits used in the SBI mode.
Address
FE2H
7
6
5
4
3
2
1
0
Symbol
SBIC
BSYE
ACKD
ACKE
ACKT
CMDD
RELD
CMDT
RELT
Bus Release Trigger Bit (W)
Command Trigger Bit (W)
Bus Release Datection Flag (R)
Command Detection Flag (R)
Acknowledge Trigger Bit (W)
Acknowledge Enable Bit (R/W)
Acknowledge Detection Flag (R)
Busy Enable Bit (R/W)
Remarks (R)
Read only
(W) Write only
(R/W) Read/write enabled
Bus release trigger bit (W)
The bus release signal (REL) trigger output control bit. The SO latch is set (1) by setting this
bit (RELT = 1), after which the RELT bit is automatically cleared (0).
RELT
Note SB0 must not be set during a serial transfer: Ensure that it is set before a transfer is started or after it is
completed.
Command trigger bit (W)
The command signal (CMD) trigger output control bit. The SO latch is cleared (0) by setting
this bit (CMDT = 1), after which the CMDT bit is automatically cleared (0).
CMDT
Note SB0 must not be set during a serial transfer: Ensure that it is set before a transfer is started or after it is
completed.
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CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Bus release detection flag (R)
Clearing Conditions (RELD = 0)
Setting Condition (RELD = 1)
➀ When a transfer start instruction is
executed
➁ When RESET is input
➂ When CSIE = 0 (See Fig. 5-25)
RELD
When the bus release signal (REL) is de-
tected
4
When SVA and SIO do not match
when an address is received
Command detection flag (R)
Clearing Conditions (CMDD = 0)
Setting Condition (CMDD = 1)
➀ When a transfer start instruction is
executed
➁ When the bus release signal (REL) is
detected
CMDD
When the command signal (CMD) is de-
tected
➂ When RESET is input
When CSIE = 0 (See Fig. 5-25)
4
Acknowledge trigger bit (W)
When ACKT is set after the end of a transfer, ACK is output in synchronization with the next
SCK. After the ACK signal is output, ACKT is automatically cleared (0).
ACKT
Note 1. ACKT must not be set (1) before completion of a serial tramsfer or during a
transfer.
2. ACKT cannot be clearedby software.
3. When ACKT is set, ACKE should be reset to 0.
Acknowledge enable bit (R/W)
Disables automatic output of the acknowledge signal (outpt by ACKT is possibel).
0
1
ACK is output is synchronization with the 9th
SCK clock cycle.
When set before end of transfer
When set after end of transfer
ACKE
ACK is output in synchronization with SCK
immediately after execution of the setting
instruction.
Acknowledge detection flag (R)
Clearing Conditions (ACKD = 0)
Setting Condition (ACKD = 1)
ACKD
➀ When a transfer is started
➁ When RESET is input
When the acknowledge signal (ACK) is de-
tected (Synchronized with the rise of SCK)
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CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Busy enable bit (R/W)
➀ Disablin of automatic busy signal output
➁ Busy signal output is stopped in synchronization with the fall of SCK immediately
after execution ofthe clearing instruction.
0
BSYE
The busy signal is output in synchronization with the fall or SCK following the
acknowledge signal.
1
(4) Serial clock selection
Serial clock selection is performed by setting bit 1 of the serial operating mode register (CSIM). Either of the
following clocks can be selected.
Table 5-7 Serial Clock Selection and Use (in SBI Mode)
Mode
Register
Serial Clock
Possible Timing for Shift
Register R/W and Serial
Transfer Start
Use
Serial Clock
Masking
Source
CSIM 1
Automatically
masked at end of
8-bit data
Possible only when serial transfer
is halted* or when SCK is high.
External
SCK
Slave CPU
0
1
transfer.
Possible only when serial transfer
is halted* or when SCK is high.
Medium-speed
serial transfer
fXX/24
*
“When serial transfer is halted” means in the operation- halted mode, or when the serial clock is masked after
an 8-bit transfer.
When the internal system clock is selected SCK stops at 8 pulses internally, but externally the count continues
until the slave is in the ready state.
105
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(5) Signals
The operation of signals and flags in SBIC in the SBI mode are shown in Figs. 5-42 to 5-47, and SBI signals are
listed in Table 5-8.
Fig. 5-42 RELT, CMDT, RELD & CMDD Operation (Master)
Tramsfer Start Directive
SIO
SCK
SB0
RELT
CMDT
RELD
CMDD
Fig. 5-43 RELT, CMDT, RELD & CMDD Operation (Slave)
Transfer Start Directive
Write to SIO
SIO
SCK
1
2
3
4
5
6
7
8
9
D7
D6
D5
D4
D3
D2
D1
D0
So Latch
RELT
(Master)
CMDT
(Master)
When Address Matches
RELD
When Address Does not Match
CMDD
106
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Fig. 5-44 ACKT Operation
SCK
SB0
6
7
8
9
ACK signal is output in 1
clock interval immediately
after ACKT is set.
D2
D1
D0
ACK
ACKT
When set in this interval
Note ACKT must not be set before the end of a transfer.
107
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Fig. 5-45 ACKE Operation
(a) When ACKE = 1 on completion of transfer
SCK
SB0
1
2
7
8
9
ACK signal is output in 9th
clock cycle.
D7
D6
D2
D1
D0
ACK
ACKE
When ACKE = 1 at this point
(b) When ACKE is set after completion of transfer
6
7
8
9
SCK
SB0
ACK signal is output in 1
clock interval immediately
after ACKE is set.
D2
D1
D0
ACK
ACKE
When ACKE is set in this interval and ACKE = 1 on
next fall of SCK
(c) When ACKE = 0 on completion of transfer
SCK
SCK
1
2
7
8
9
ACK signal is not output.
D7
D6
D2
D1
D0
ACKE
When ACKE = 0 at this point
(d) When ACKE = 1 interval is short
SCK
ACK signal is not output.
D2
D1
D0
SB0
ACKE
When ACKE is set and cleared in this interval and
ACKE = 0 on next fall of SCK
108
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
Fig. 5-46 ACKD Operation
(a) When ACK signal is output in 9th SCK clock interval
Transfer Start Directive
SIO
Start of Transfer
SCK
SB0
6
7
8
9
ACK
D2
D1
D0
ACKD
(b) When ACK signal is output after 9th SCK clock interval
Transfer Start Directive
SIO
Start of
Transfer
SCK
SB0
6
7
8
9
ACK
D2
D1
D0
ACKD
(c) Clearing timing when transfer start directive is given during busy state
★
Transfer Start Directive
SIO
Start of Transfer
SCK
SB0
7
8
9
6
ACK
BUSY
D2
D1
D0
D7
D6
ACKD
Fig. 5-47 BSYE Operation
SCK
SB0
6
7
8
9
BUSY
ACK
D2
D1
D0
BSYE
When BSYE is Reset in this
Interval and BSYE = 0 when
SCK Falls
When BSYE = 1 at
this Point
109
Table 5-8 Signals in SBI Mode (1/2)
Output
Device
Output
Meaning of
Signal
Effect on
Flag
Signal Name
Timing Chart
Definition
Condition
SB0 rising edge when
SCK = 1
Outputs next CMD
signal and indicates
send data is address.
Bus release
signal (REL)
Master
• RELT set
• RELD set
• CMDD
SCK
SB0
“H”
Cleared
SB0 falling edge when
SCK = 1
i) After REL signal
output send data is
address.
Command
Master
• CMDT set • CMDD set
signal (CMD)
SCK
SB0
“H”
ii) send data with no
REL signal output is
command.
Low-level signal output to
SB0 in 1 SCK clock intercal
after serial receive comple-
tion.
Receive completion
Acknowledge
singnl (ACK)
Master/
slave
➀ACKE = 1 • ACKD set
➁ACKE set
Low-level signal output to
SB0 after Acknowledge
signal.
Busy signal
(BUSY)
Slave
Slave
Serial transmission/
reception disabled
because processing is in
progress.
• BSYE = 1
—
—
SCK
SB0 D0
SB0
9
BUSY
ACK
ACK
READY
READY
BUSY
High-level signal output to
SBO before start or after
completion of serial transfer.
Serial transmission/
reception enabled
Ready signal
(READY)
➀BSYE = 0
➁Execution
of instruc-
tion to
D0
write data
to SIO
(transfer
start
directive)
Table 5-8 Signals in SBI Mode (2/2)
Output
Device
Output
Meaning of
Signal
Effect on
Flag
Signal Name
Timing Chart
Definition
Condition
Synchronization clock for
output of address/command/
data, ACK signal,
Timing of signal output
to serial data bus
Serial Clock
(SCK)
Master
Exection of IRQCSI set
instruction
to write to
SIO when
CSIE = 1
(rise of 9th
SCK clock
cycle) *1
SCK
SB0
1
2
7
8
9
10
Synchronous BUSY signal,
etc.
Address/command/ data is
transferred in first 8 cycles.
(serial
transfer
start
8-bit data transferred in
synchronization with SCK
after REL signl and CMD
signal output.
SCK
SB0
1
7
8
Address value of slave
device on serial bus
Address
Master
Master
2
(A7 to A0)
directive) *2
REL
CMD
1
8-bit data transferred in
synchronization with SCK
after CMD signal only is
output without output of REL
signal.
Directive, meddage,
etc., to slave device.
SCK
SB0
2
7
8
Command
(C7 to C0)
CMD
8-bit data transferred in
synchronization with SCK
with no output of either REL
signal or CMD signal.
Data to ve processed by
slave or master device
Data
Master/
slave
(D7 to D0)
SCK
SB0
1
2
7
8
*
1. When WUP = 0, IRQCSI is always set on the 9th rise of SCK.
When WUP = 1, IRQCSI is set on the 9th rise of SCK only with an address is receive and that address matches the value of the slave address register
(SVA).
2. In data transmission/reception, when in the BUSY stare, the transfer starts after transition to the READY state.
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(6) Pin configuration
The configuration of the serial clock pin (SCK) and the serial data bus pin SB0 is as shown below.
(a) SCK .................... Pin for input/output of serial clock
➀ Master ........ CMOS, push-pull output
➁ Slave ........... Schmitt input
(b) SB0 .................... Serial data input/output dual- function pin
For both master and slave, output is N-ch open-drain, input is Schmitt input.
Since the serial data bus line output is N-ch open-drain, an external pull-up resistor is necessary.
Fig. 5-48 Pin Configuration Diagram
Slave Device
Master Device
(Clock Output)
Clock Output
(Clock Input)
Clock Input
Serial Clock
R
L
N-ch Open Drain
SB0
SB0 N-ch Open Drain
Serial Data Bus
SO
SI
SO
SI
Note Since the N-ch open drain must be turned off during data reception, FFH should be written to SIO
beforehand. It can always be turned off during transmission.
However, when the wake-up function specification bit (WUP) is 1, the N-ch transistor is always off, and
therefore FFH need not be written to SIO prior to reception.
112
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(7) Address match detection method
In the SBI mode, master address communication is used to select a specific slave and start communication.
Address match detection is performed by hardware. A slave address register (SVA) is provided, and IRQCSI is
set only when the address sent from the master and the value set is SVA match in the wake-up state (WUP = 1).
Note 1. Detection of the slave selected/nonselected state is performed by detection of a match with a slave
address received after bus release (when RELD = 1).
An address match interrupt (IRQCSI) generated when WUP = 1 is normally used for this match detection.
Therefore, detection of selection/nonselection by the slave address should be performed with WUP =
1.
2.
For selection/nonselection detection without using an interrupt when WUP = 0, the address detection
method is not used: Instead, detection should be performed by transmission/reception of commands
set beforehand by the program.
(8) Error detection
In the SBI mode, since the status of the serial bus SB0 pin during transmission is also written into the SIO shift
register of the transmitting device, transmission errors can be detected in the following ways:
(a) Comparison of pre-transmission and post-transmission SIO data
In this case, a transmission error is judged to have been generated if the two data items are different.
(b) Use of slave address register (SVA)
Transmission is performed after also setting the send data in the SVA register. After transmission the COI
bit of the serial operating mode register (CSIM) (the match signal from the address comparator) is tested: “1”
indicates normal transmission, and “0”, a transmission error.
(9) Communication operation
With the SBI, the master normally selects the slave device to be communicated with from among the multiple
connected devices by outputting an address onto the serial bus.
After the target communication device has been determined, commands and data are exchanged between the
master device and slave device, thus implementing serial communication.
Data communication timing charts are shown in Figs. 5-49 through 5-52.
In the SBI mode, shift register shift operations are performed in synchronization with the fall of the serial clock
(SCK), and send data is latched in the SO latch and is output MSB-first from the SB0/P02 or P03 pin. Receive data
input to the SB0 pin is latched in the shift register on the rise of SCK.
113
Fig. 5-49 Address Transmission form Master Device to Slave Device (WUP = 1)
Master Device Processing
(Transmission Side)
Program
Processing
Write
to SIO
CMDT
Setting
CMDT
Setting
Interrupt Servicing
(Preparation for Next Serial Transfer)
RELT
Setting
SCK
IRQCSI
Gene-
ration
Hardware
Operation
ACKD
Setting
Stop-
page
Serial Transmit Operation
Transfer Line
SCK Pin
1
2
3
7
8
9
4
5
6
READY
ACK BUSY
SB0 Pin
A7
A4
A6
A5
A3
A2
A1
A0
Address
Slave Device Processing
(Reception Side)
Program
Processing
BUSY
Clear-
ance
ACKT
Setting
WUP
0
IRQCSI
Gene-
ration
Hardware
Operation
CMDD
Clear-
ance
BUSY
Clear-
ance
BUSY
Output
ACK
Output
CMDD
Setting
CMDD
Setting
Serial Receive Operation
RELD
Setting
(When SVA = SIO)
Fig. 5-50 Command Transmission from Master Device to Slave Device
Master Device Processing Transmission Side)
Program
Processing
CMDT Write
Setting
Interrupt Servicing
(Preparation for Next Serial Transfer)
to SIO
SCK
Stop-
page
IRQCSI
Genera-
tion
ACKD
Setting
Hardware
Operation
Serial Transmit Operation
Transfer Line
SCK Pin
SB0 Pin
1
2
3
4
5
6
7
8
9
ACK
BUSY
READY
C7
C6
C5
C4
Command
C3
C2
C1
C0
Slave Device Processing Reception Side)
BUSY
Clear-
ance
SIO
Read
Command
Analysis
ACKT
Setting
Program
Processing
IRQCSI
Genera-
tion
BUSY
Clear-
ance
ACK
Output
BUSY
Output
Hardware
Operation
CMDD
Setting
Serial Receive Operation
Fig. 5-51 Data Transmission from Master Device to Slave Device
Master Device Processing
(Transmission Side)
Interrupt Servicing
(Preparation for Next Serial Transfer)
Write
to SIO
Program
Processing
SCK
Stop-
page
IRQCSI
Genera-
tion
ACKD
Setting
Hardware
Operation
Serial Transmit Operation
Transfer Line
SCK Pin
1
2
3
4
5
7
8
9
6
ACK
BUSY
READY
SB0 Pin
D7
D5
D4
D2
D1
D0
D6
D3
Data
Slave Device Processing
(Reception Side)
BUSY
Clear-
ance
Program
Processing
ACKT
Setting
SIO
Read
IRQCSI
Genera-
tion
BUSY
Clear-
ance
ACK
Output
Hardware
Operation
BUSY
Output
Serial Receive Operation
★
Fig. 5-52 Data Transmission from Slave Device to Master Device
Master Device Processing (Reception Side)
ACKT
Setting
Program
Processing
SIO
Read
FFH Write
to SIO
FFH Write
to SIO
Receive Data Processing
Serial
SCK
Stop-
page
IRQCSI
Genera-
Hardware
Operation
ACK
Output
Serial Receive Operation
Reception
tion
Transfer Line
SCK Pin
1
2
3
4
5
6
7
8
9
1
2
ACK BUSY
D7
D6
BUSY
READY
D7
D6
D5
D4
Data
D3
D2
D1
D0
SB0 Pin
READY
Slave Device Processing (Transmission Side)
Write
Write
Program
to
to
Processing
SIO
SIO
IRQCSI
Genera-
tion
Hardware
Operation
BUSY
Clear-
ance
BUSY
Clear-
ance
ACKD
Setting Output
BUSY
Serial Transmit Operation
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(10) Start of transfer
When the following two conditions are met a serial transfer is started by setting transfer data in the shift register
(SIO).
• The serial interface operatio enable/disable bit (CSIE) = 1.
• After an 8-bit serial transfer, the internal serial clock is stopped or SCK is high.
Note 1. The transfer will not be started if CSIE is set to “1” after data is written into the shift register.
2. Since the N-ch transistor must be turned off during data reception, FFH should be written to SIO
beforehand.
However, when the wake-up function specification bit (WUP) is 1, the N-ch transistor is always off, and
therefore FFH need not be written to SIO prior to reception.
3. If data is written to SIO when the slave is in the busy state, that data is not lost.
The transfer starts when the busy state is released and the SB0 input becomes high (ready state).
When an 8-bit transfer ends, the serial transfer stops automatically and the IRQCSI interrupt request flag is set.
Example In the following example the data in the RAM specified by the HL register is transferred to SIO, and at
the same time the SIO data is fetched into the accumulator and the serial transfer is started.
MOV XA, @HL ; Fetch send data from RAM
XCH XA, SIO ; Exchange send data with receive data and start transfer
(11) Points to note concerning SBI mode
(a) Detection of the slave selected/nonselected state is performed by detection of a match with a slave address
received after bus release (when RELD = 1).
An address match interrupt (IRQCSI) generated when WUP = 1 is normally used for this match detection.
Therefore, detection of selection/nonselection by the slave address should be performed with WUP = 1.
(b) For selection/nonselection detection without using an interrupt when WUP = 0, the address detection
method is not used: Instead, detection should be performed by transmission/reception of commands set
beforehand by the program.
(c) When WUP is set to 1 during BUSY signal output, BUSY is not released. With the SBI, the BUSY signal is
output following a BUSY release directive until the next fall of the serial clock (SCK). When WUP is set to
1, a check must be performed to ensure that SB0 has been driven high after BUSY is released before setting
WUP to 1.
118
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(12) SBI mode application
This section presents examples of applications in which serial data communication is performed in SBI mode.
In these application examples, the µPD75402A is operated as a slave CPU on the serial bus.
Also, the master can be changed by a command.
(a) Serial bus configuration
In the serial bus configuration in the application examples given here, the µPD75402A is connected to the
bus line as one of the devices on the serial bus.
The µPD75402A uses two pins: The serial data bus SB0 (P02/SO), and the serial clock SCK (P01).
An example of the serial bus configuration is shown in Fig. 5-53. Only addresses C0H through C7H can be
allocated to the µPD75402A.
Fig. 5-53 Example of Serial Bus Configuration
VDD
Master CPU
Slave CPU
µPD75308
µPD75328
SB0 (SB1)
SB0 (SB1)
SCK
Address 1
SCK
Slave CPU
µPD75402A
SB0
SCK
Address C0H
Slave IC
SB0 (SB1)
Address N
SCK
119
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(b) Description of commands
(i) Command types
The following command types are used in these application examples.
➀ READ command
➁ WRITE command
➂ END command
: Performs data transfer from slave to master.
: Performs data transfer from master to slave.
: Notifies slave of completion of WRITE command.
: Notifies slave of suspension of WRITE command.
4
STOP command
➄ STATUS command : Reads slave-side status.
6
RESET command
: Makes currently selected slave non-selected.
7
CHGMST command : Passes mastership to slave side.
(ii) Communication procedure
The procedure for communication between master and slave is as follows.
➀ The master starts the communication by transmitting the address of the slave to be communicated
with and selecting the slave (chip selection).
When the slave receives the address, it communicates with the master by returning ACK. (The
slave changes from non-selected to selected status.)
➁ Communication is performed between the slave selected by the processing in ➀and the master
by the transfer of commands and data.
However, as command and data transfers are one-to-one master- slave transfers, other slaves
must be in the non-selected status.
➂ Communication is ended by the slave changing to non-selected status. The slave changes to non-
selected status in the following cases:
• When a RESET command is sent from the master, the selected slave changes to non-selected
status.
• When the master is changed by the CHGMST command, the device which is changed from
master to slave changes to non-selected status.
120
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(iii) Command formats
The transfer format of each command is shown below.
➀ READ command
This command performs a read from the slave. The read data length is variable between 1 and
256 bytes, and is specified as a parameter by the master. If 00H is specified as the data length, this
is interpreted as a 256-byte data transfer specification.
Fig. 5-54 READ Command Transfer Format
M
S
M
S
S
S
S
S
ACK
ACK
Data N
ACK
READ
ACK
Data Length
Data 0
Data
Data
Command
Data
Remarks M : Output by master
S : Output by slave
After the slave receives the data length, if the transmissible data is equal to or greater than that
data length, the slave returns ACK. If the data is insufficient, ACK is not returned and an error is
generated.
When a data transfer is performed, the slave compares the SIO contents before and after the
transfer to check whether the data was correctly output onto the bus. If the SIO contents before and
after the transfer are different, ACK is not returned and an error is generated.
➁ WRITE, END and STOP commands
This command performs a data write to the slave. The write data length is variable between 1 and
256 bytes, and is specified as a parameter by the master. If 00H is specified as the data length, this
is interpreted as a 256-byte data transfer specification.
Fig. 5-55 WRITE & END Command Transfer Format
M
M
M
S
M
S
M
S
S
S
ACK
Data Length
ACK
ACK
Data N
ACK
END
ACK
WRITE
Data 0
Data
Data
Data
Command
Command
Remarks M : Output by master
S : Output by slave
121
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
After the slave receives the data length, if the area for storing the receive data is at least as large as
that data length, the slave returns ACK. If the data storage area is too small, ACK is not returned and an
error is generated.
When all the data has been transferred, the master sends an END command. This command notifies
the slave that all the data has been correctly transferred.
The slave may also receive an END command before the reception of all the data. In this case, the data
up to the reception of the END command is valid.
When data is transmitted, the master compares the SIO contents before and after the transmission
to check whether the data was correctly output onto the bus. If the SIO contents before and after the
transmission are different, the master suspends data transmission by sending a STOP command.
Fig. 5-56 STOP Command Transfer Format
M
S
M
S
Data
Data
ACK
STOP
ACK
Command
Data Check
Error Generation
Data Transfer Suspended
Remarks M : Output by master
S : Output by slave
When the slave receives a STOP command, the byte of data received immediately before the command
is invalid.
122
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
➂ STATUS command
This command is used to read the status of the currently selected slave.
Fig. 5-57 STATUS Command Transfer Format
S
M
S
S
ACK
Status
ACK
STATUS
Data
Command
Remarks M : Output by master
S : Output by slave
The format of the status byte returned by the slave is shown below.
Fig. 5-58 STATUS Command Status Format
MSB
Status
LSB
7
6
5
4
3
2
1
0
All 0s
Bit indicating possibility of data transmission
0 : No data for transmission
1 : 1 or more bytes of send data ready
Bit indicating possibility of data reception
0 : No receive data storage area
1 : 1 or more bytes of receive data storage area ready
Bit indicating error occurrence
0 : No error
1 : Error occurred in previous transfer
Bit indicatin possibility of change of master
0 : Chang of master not possible
1 : Change of mster possible
When the slave sends status data, it compares the SIO contents before and after transmission and
if they do not match an error is generated and no ACK is returned.
123
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
RESET command
4
This command is used to change the currently selected slave to non-selected status. All slaves
can be placed in non-selected status by sending the RESET command.
Fig. 5-59 RESET Command Transfer Format
M
S
RESET
ACK
Command
Remarks M : Output by master
S : Output by slave
➄ CHGMST command
This command passes mastership to the currently selected slave.
Fig. 5-60 CHGMST Command Transfer Format
S
M
S
S
ACK
Data
ACK
CHGMST
Data
Command
Remarks M : Output by master
S : Output by slave
When a slave receives the CHGMST command, it determines whether it can assume mastership
and returns data to the master. This data is as follows:
• 0FFH : Change of master possible
• 00H : Change of master not possible
When the slave sends this data, it compares the SIO contents before and after transmission and
if they do not match an error is generated and no ACK is returned.
If there is no error after the 0FFH data has been transmitted, the master operates as a slave and
the slave operates as the master from that point on.
124
CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS
(iv) Error occurrence
Operation in the event of an error in communication is described below.
A slave indicates the occurrence of an error by failing to return ACK to the master. When an error
occurs, the status bit indicating the occurrence of an error is set and all command processing being
executed is canceled.
After sending or receiving a byte, the master checks for ACK from the slave. If ACK is not returned
by the slave within a certain time after the end of transmission or reception, an error is judged to have
occurred and the master outputs an ACK signal (as a dummy).
Fig. 5-61 Master and Slave Operations after an Error
End of Reception
Judges error to have occurred,
stops processing
Slave
Processing
SB0
Error Data
ACK
ACK Wait Time
Master
Processin
Checks for ACK from slave
Judges error to have
occurred, outputs ACK
End of Transmission
Start of ACK Check
Errors are generated in the following circumstances:
•
Errors generated on the slave side
➀ If the command transfer format is wrong.
➁ If an undefined command is received.
➂ If the transferred data length is insufficient in a READ command.
4
If the data storage area is too small in a WRITE command.
➄ If the data changes in a READ, STATUS or CHGMST command data transmission.
ACK is not returned if any of the above cases.
•
Errors generated on the master side
If the data changes in a WRITE command data transmission, a STOP command is sent to the slave.
125
CHAPTER 6. INTERRUPT FUNCTIONS
On the µPD75402A there are 3 vectored interrupt sources and one testable input, enabling a wide variety of
applications to be handled.
Moreover, the µPD75402A’s interrupt control circuit has the following special features, making possible
extremely fast interrupt servicing.
(a) Acknowledgment enabling/disabling is possible by means of the interrupt master enable flag (IME) and
the interrupt enable flag (IE×××).
(b) Any desired interrupt service start address can be set using the vector table (for rapid starting of the actual
interrupt service program).
(c) Interrupt request flag (IRQ×××) can be tested and cleared (allowing checking of interrupt generation by
software).
(d) Standby mode (HALT) can be released by an interrupt request (release source is selectable from other than
INT0 by means of interrupt enable flag).
6.1 INTERRUPT CONTROL CIRCUIT CONFIGURATION
The interrupt control circuit is configured as shown in Fig. 6-1, with each hardware item mapped onto data
memory space.
126
Fig. 6-1 Interrupt Control Circuit Block Diagram
Internal Bus
3
IME
IST0
Interrupt Enable Flag (IE×××)
IM0
Decoder
Sampling Clock
Noise Elimination
Circuit
VRQ1
INT
BT
IRQBT
VRQ2
VRQ3
Priority
Control
Circuit
Vector
Table
Address
Generation
Circuit
Edge
INT0/P10
INT2/P12
IRQ0
Detection
Circuit
INTCSI
IRQCSI
IRQ2
Rising Edge
Detection
Circuit
Analog Delay Noise
Elimination Circuit
Standby Release Signal
CHAPTER 6. INTERRUPT FUNCTIONS
6.2 INTERRUPT SOURCE TYPES AND VECTOR TABLE
The µPD75402A’s interrupt source types and interrupt vector table are shown in Table 6-1 and Fig. 6-2.
Table 6-1 Interrupt Request Source Types
Interrupt Request
Generation Source
Interrupt
Internal/
External
Vectored Interrupt Request Signal
(Vector Table Address)
Priority*1
VRQ1(0002H)
INTBT
Internal
1
(Basic time interval signal from basic interval timer)
INT0 (INT0 pin input specified edge detection)
INTCSI (Serial data transfer termination signal)
INT2*2 (INT2 pin input rising edge detection)
External
Internal
External
2
3
VRQ2(0004H)
VRQ3(0008H)
Testable input signal (sets) IRQ2 flag)
*
1. The interrupt priority is the order of precedence when multiple interrupt requests occur simultaneously.
2. A test source. This is affected by an interrupt enable flag in the same way as an interrupt source, but no
vectored interrupt is generated.
★
Fig. 6-2 Interrupt Vector Table
Address
0 0 0 2 H
0
0
0
0
0
0
0
0
0
0
INTBT start address (high-order 3 bits)
INTBT start address (low-order 8 bits)
INT0 start address (high-order 3 bits)
INT0 start address (low-order 8 bits)
0 0 0 4 H
0 0 0 8 H
0
0
0
0
0
INTCSI start address (high-order 3 bits)
INTCSI start address (low-order 8 bits)
The interrupt priority shown in the table shows the order in which interrupts are executed when multiple interrupt
requests are generated simultaneously or when multiple interrupt requests are pending.
The vector table contains the interrupt service routine start addresses. Vector table setting is performed by the
VENTn assembler pseudoinstruction.
Example INTBT vector table setting.
VENT1
GOTOBT
↑
↑
Address 0002
vector table
Symbol indicating start address
of interrupt service routine
Note The vector table address specified by VENTn (n = 1, 2 and 4) is address 2n.
Example INTBT and INT0 vector table setting.
VENT1
VENT2
GOTOBT
GOTO0
128
CHAPTER 6. INTERRUPT FUNCTIONS
6.3 INTERRUPT CONTROL CIRCUIT HARDWARE
(1) Interrupt request flag & interrupt enable flag
There are four interrupt request flags (IRQ×××) corresponding to the interrupt sources (interrupt: 3, test: 1) as
follows.
INT0 interrupt request flag (IRQ0)
INT2 interrupt request flag (IRQ2)
BT interrupt request flag (IRQBT)
Serial interface interrupt request flag (IRQCSI)
An interrupt request flag is set (1) by generation of an interrupt request and cleared (0) automatically by execution
of an interrupt service.
There are four interrupt enable flags (IE×××) corresponding to the interrupt request flags as follows.
INT0 interrupt enable flag (IE0)
INT2 interrupt enable flag (IE2)
BT interrupt enable flag (IEBT)
Serial interface interrupt enable flag (IECSI)
An interrupt enable flag enables an interrupt when its contents are “1” and disables it when 0.
When an interrupt request flag is set and the interrupt enable flag permits an interrupt, a vectored interrupt
request (VRQn) is generated. This signal is also used to release standby mode (HALT mode) (with the exception of
VRQ2).
The interrupt request flags and interrupt enable flags are manipulated by bit-handling instructions and 4-bit
memory handling instructions. In addition, the interrupt enable flags are manipulated by the EI IE××× instruction
and the DI IE××× instruction. The SKTCLR is normally used for interrupt request flag testing.
Example EI
IE0
; INT0 enabled
DI
IEBT
IRQCSI
; INTBT disabled
SKTCLR
; Skip and clear if IRQCSI is 1
When the interrupt request flag is set by an instruction, although no interrupt is generated, a vectored interrupt
is executed in the same way as when an interrupt is generated.
With a RESET input, the interrupt request flags and interrupt enable flags are cleared (0) and all interrupts are
disabled.
Table 6-2 Interrupt Request Flag Setting Signal
Interrupt Request Flag
Interrupt Enable Flag
Interrupt Request Flag Setting Signal
Set by basic time interval signal from basic interval timer.
Set by INT0/P10 pin input signal edge detection. Detected
edge is selected by INT0 mode register (IM0).
Set by serial interface serial data transfer operation
termination signal.
IRQBT
IRQ0
IEBT
IE0
IRQCSI
IRQ2
IECSI
IE2
Set by INT2/P12 pin input signal rising edge detection.
129
CHAPTER 6. INTERRUPT FUNCTIONS
(2) External interrupt input pin hardware
The configuration of INT0 and INT2 is shown in Fig. 6-3.
Fig. 6-3 Configuration of INT0 and INT2
Sampling Clock
Noise Elimina-
tion Circuit
Edge Detec-
tion Circuit
INT0
INT0/P10
(IRQ0 Setting Signal)
IM01, IM00
IM03
Φ
Selector
2
fxx
64
Φ
Analog Delay
Noise Elimina-
tion Circuit
Rising Edge
Detection
Circuit
INT2
INT2/P12
(IRQ2 Setting Signal)
Input Buffer
with Hysteresis
Characteristics
IM0
Input
Buffer
4
Internal Bus
INT0 functions as an external interrupt input on which sampling clock noise elimination and detected edge
selection can be performed. The INT0 noise elimination circuit detects a change in level in 2 sampling clock pulses.
Therefore, pulses narrower than the width of the 2 cycles (2tCY* or 128/fXX) of sampling clock are eliminated as noise,
and a pulse exceeding the width is properly acknowledged as an interrupt signal (see Fig. 6-4). One of 3 clocks can
be selected as the timing clocks.
*
Cycle time
130
CHAPTER 6. INTERRUPT FUNCTIONS
Fig. 6-4 INT0 Noise Elimination Circuit Input/Output Timing
tSMP
tSMP
tSMP
tSMP
tSMP
➀ꢀ Sampling Cycle
L
L
(tSMP) or Less
INT0
Eliminated as Noise
H
Sheped
Output
➁ꢀ 1 to 2 Times tSMP
H
L
L
L
(a)
INT0
Sheped
Output
H
L
L
(b)
INT0
Eliminated as Noise
H
Sheped
Output
H
2 or More Times
➂ꢀ
L
L
tSMP
INT0
Sheped
Output
Remarks tSMP = tCY or 64/fXX
Specification of the detected edge of the INT0 input and selection of the sampling clock is performed by the edge
detection mode register (IM0).
As signals are also input via the noise elimination circuit when the INT0 pin inputs data as a port, the input data
must be of sufficient width to avoid being eliminated as noise.
INT2 functions as an externally testable input which sets a testable flag on detection of a rising edge. Noise
elimination by the sampling clock is not performed, but as there is a function for eliminating pulses which are
narrower than the analog delay, a signal of adequate width must be input as in the case of INT0 (see Fig. 6-5).
Fig. 6-5 INT2 Input Noise Elimination
INT2 Input
Analog
Delay
Analog
Delay
Eliminated
as Noise
INT2 Input
Received
131
CHAPTER 6. INTERRUPT FUNCTIONS
The format of the edge detection mode register (IM0) which is used to select the detected edge is shown in Fig.
6-6. IM0 is set by 4-bit memory handling instructions.
On an RESET input, all bits of IM0 are cleared to 0 and the rising edge is specified for INT0.
Fig. 6-6 Edge Detection Mode Register Format
Address
FB4H
3
2
0
1
0
Symbol
IM0
IM03
IM01 IM00
Detected edge specification
0
0
1
1
0
1
0
1
Rising edge specification
Falling edge specification
Rising and falling edge specification
Ignored (interrupt request flag is not set)
Sampling clock specification
0
1
Φ (0.95 µs/1.91 µs/15.3 µs: operating at 4.19 MHz)
fx/64 (15.3 µs: Operating at 4.19 MHz)
Note As the interrupt request flag may be set when the edge detection mode register is modified, the following
procedure should be used: Disable interrupts and modify the mode register in advance, clear the interrupt
request flag with the CLR1 instruction, and then enable interrupts again. Also, when fX/64 is selected as
the sampling clock by modifying IM0, the interrupt request flag must be cleared after the elapse of 16
machine cycles following the mode register modification.
(3) Interrupt master enable flag (IME)
The interrupt master enable flag specifies acknowledgment enabled/disabled for all interrupts.
IME is manipulated by the EI/DI instructions.
With a RESET input, IME is cleared to 0 and acknowledgment of all interrupts is disabled.
Fig. 6-7 IME Format
Address
FB2H
3
IME
Interrupt master enable flag (IME)
All interrupts are disabled, vectored interrupts
0
are notinitiated.
Interrupt enabling/disabling is controlled by the
corresponding interrupt enable flag.
1
132
CHAPTER 6. INTERRUPT FUNCTIONS
(4) Interrupt status flag
The interrupt status flag (IST0) is the flag which shows the status of the processing currently being executed by
the CPU, and is contained in the PSW.
The interrupt priority control circuit performs interrupt control according to the contents of this flag as shown
in Table 6-3.
IST0 cannot be modified by 4-bit handling instructions or bit-handling instructions. IST0 is always set to 1 during
interrupt servicing. Therefore, it is not possible to write 0 to IST in the interrupt service routine which would result
in multiple interrupt.
After being saved to stack memory together with the rest of the PSW when an interrupt is acknowledged, IST0
is automatically set to 1. When an RETI instruction is executed, the original IST0 value (0) is restored.
A RESET input clears (0) the flag contents.
Table 6-3 IST0 Interrupt Servicing Status
Executing
Interrupt Requests of which
Acknowledgment is Possible
After Interrupt
CPU Processing
IST0
Processing Status
Acknowledgment
IST0
1
Status 0
Status 1
Acknowledgment of all interrupts
possible
Normal program
processing in
progress
0
1
Acknowledgment of all interrupts
disabled
–
Interrupt servicing in
progress
133
CHAPTER 6. INTERRUPT FUNCTIONS
6.4 INTERRUPT SEQUENCE
When an interrupt is generated, it is serviced by the procedure shown in Fig. 6-8.
Fig. 6-8 Interrupt Servicing Procedure
Interrupt (INT×××) generation
IRQxxx set
NO
Hold pending until
IExxx is set
IExxx set?
YES
Corresponding VRQn
generation
NO
NO
Hold pending
until IME is set
IME=1
YES
Hold pending until
end of processing
in execution
IST0=0
YES
Save PC and PSW contents to stack memory; place data in vector table corresponding
to initiated VRQn into PC.
Change IST0 contents to 1
Reset (0) acknowledged IRQxxx
Branch to start address of interrupt service program proccessing
134
CHAPTER 6. INTERRUPT FUNCTIONS
6.5 MACHINE CYCLES BEFORE INTERRUPT SERVICING
On the 75X, the machine cycles from the setting of the interrupt request flag (IRQn) until execution of the interrupt
routine program are as shown below.
(1) When IRQn is set during execution of an interrupt control instruction
When IRQn is set during execution of an interrupt control instruction, the interrupt routine program is executed
after 3 machine cycles of interrupt servicing have been performed following execution of the next instruction.
Interrupt
(INTxxx)
generation
A
B
C
D
A : Setting of IRQn
B : Execution of next instruction (between 1 and 3 machine cycles depending on instruction)
C : Interrupt servicing (3 machine cycles)
D : Execution of interrupt routine
Remarks 1. An interrupt control instruction is an instruction which manipulates interrupt-related hardware (data
memory FB×H address). These instructions comprise the DI and EI instructions.
2. The 3 machine cycles of interrupt servicing include the time for manipulation of the stack on
acknowledgment of an interrupt, etc.
Note 1. If there are a number of consecutive interrupt control instructions, the interrupt routine program is
executed after 3 machine cycles of interrupt servicing have been performed following execution of the
instruction which follows the last interrupt control instruction executed.
2. When IRQn is set, or when the interrupt control instruction executed thereafter is a DI instruction, the
interrupt request by which IRQn was set is held pending.
135
CHAPTER 6. INTERRUPT FUNCTIONS
(2) When IRQn is set during execution of an instruction other than an interrupt control instruction
(a) When IRQn is set in the last machine cycle of the instruction being executed
In this case, the interrupt routine program is executed after 3 machine cycles of interrupt servicing have been
performed following execution of the instruction which follows the instruction being executed.
Instruction other
than interrupt
control instruction
A
B
C
D
A : Setting of IRQn
B : Execution of next instruction (between 1 and 3 machine cycles depending on instruction)
C : Interrupt servicing (3 machine cycles)
D: Execution of interrupt routine
Note If the next instruction is an interrupt control instruction, the interrupt routine program is executed after
3 machine cycles of interrupt servicing have been performed following execution of the instruction which
follows the last interrupt control instruction executed. Also, if the interrupt control instruction executed
after IRQn is set is a DI instruction, the interrupt request by which IRQn was set is held pending.
(b) When IRQn is set before the last machine cycle of the instruction being executed
In this case, the interrupt routine program is executed after 3 machine cycles of interrupt servicing have been
performed following the instruction being executed.
Instruction other
than interrupt
control instruction
A
C
D
A : Setting of IRQn
C : Interrupt servicing (3 machine cycles)
D : Execution of interrupt routine
136
CHAPTER 6. INTERRUPT FUNCTIONS
6.6
INTERRUPT APPLICATIONS
When the interrupt function is used, the following setting are first carried out in the main program.
➀
➁
➂
The interrupt enable flag corresponding to the interrupt to be used is set to “1” (EI IE××× instruction).
If INT0 is used, the active edge is selected (IM0 setting).
The interrupt master enable flag (IME) is set to “1” (EI instruction).
Return from the interrupt service program is by means of an RETI instruction.
(1) Interrupt enabling/disabling
<Main Program>
➀ Reset
Interrupts disabled
➁ EI IE0
➁ EI IECSI
➂ EI
INT0 & INTCSI enabled
➃ DI IE0
INTCSI enabled
➄ DI
Interrupts disabled
➀
➁
All interrupts disabled by RESET input.
Interrupt enable flag set by EI IE××× instruction.
At this stage, all interrupts are still disabled.
Interrupt master enable flag set by EI instruction.
At this stage, INT0 & INTCSI are enabled.
➂
4
Interrupt enable flag cleared by DI IE××× instruction; INT0 disabled.
All interrupts disabled by DI instruction.
➄
137
CHAPTER 6. INTERRUPT FUNCTIONS
(2) Example using INTBT, INT0 (falling edge active), and INTCSI
<Main Program>
; MBE = 0
➀
Reset
➁
➂
MOV
MOV
CLR1
A, #1
IM0, A
IRQ0
IEBT
IE0
EI
EI
EI
EI
IECSI
Status 0
<INT0 Service Program>
➃
INT0
Status 1
➄RETI
Status 0
➀
➁
➂
4
All interrupts disabled and status 0 set by RESET input.
INT0 set to falling edge active.
Interrupts enabled by EI and EI IE××× instructions.
On fall of INT0, INT0 interrupt service program is started, status is changed to 1 and all interrupts are
disabled.
➄
RETI instruction effects return from interrupt, restores status to 0, and enables interrupts.
138
CHAPTER 6. INTERRUPT FUNCTIONS
(3) Pending interrupt execution - interrupt input in interrupt disabled state
<Main program>
Reset
EI IE0
<INT0 Service Program>
➀
INT0
➁
EI
➂
INTCSI
RETI
<INTCSI Service Program>
➃
EI IECSI
RETI
➀
➁
➂
4
Although INT0 is set in the interrupt disabled state, the interrupt flag is held pending.
The INT0 service program is started at point at which interrupts are enabled by the EI instruction.
Same as ➀ .
The INTCSI service routine is started at the point at which the pending INTCSI is enabled.
139
CHAPTER 6. INTERRUPT FUNCTIONS
(4) Pending interrupt execution
<Main Program>
<Main Program>
Reset
EI
EI
EI
IECSI
IE0
<INT0 Service Program>
INT0
➀
INTCSI
➁
RETI
<INTCSI Service Program>
RETI
➀
➁
If INT0 and INTCSI are generated simultaneously (during execution of the same instruction), INT0, which
has the higher interrupt priority, is executed first (INTCSI is held pending).
When the INT0 service program is ended by the RETI instruction, the pending INTCSI service program is
started.
140
CHAPTER 7. STANDBY FUNCTION
The µPD75402A has a standby function which can reduce the system power consumption. The standby function
has the following two modes:
• STOP mode
• HALT mode
(1) STOP mode
In this mode, the main system clock oscillator is stopped and the whole system stops. The CPU current drain is
reduced considerably.
Data memory low voltage (up to VDD = 2 V) hold is also possible. Therefore, this mode is effective when retaining
the contents of data memory at an ultra-low current drain.
The µPD75402A STOP mode cannot be reset by interrupt request. It is reset only by RESET input.
(2) HALT mode
This mode stops the CPU operation clock. The system clock oscillator continues to oscillate. In this mode, the
current drain is not reduced as much as the STOP mode, but this mode is effective when desiring to resume
processing immediately by interrupt request and when desiring to perform intermittent operation, such as timer
operation.
The HALT mode is reset by RESET input or interrupt request.
In either mode, the contents of the registers, flags, and data memory immediately before setting to the standby
mode are retained. Because the states of the I/O port output latch and the output buffer are retained, the state of
the I/O ports is preprocessed so that the current drain of the entire system is minimum.
Note 1. Low current, low voltage operation is possible by switching the standby mode and CPU clock. However,
in either case, the time described in paragraph 5.2.3 is necessary between operation of the PCC register
and selection of the new clock and the start of operation by the new clock after switching. Therefore,
when combining the clock switching function and standby mode, set the µPD75402A to the standby
mode after the time required for switching has elapsed.
★
2. When using the standby mode, ensure that the consumption current at the input/output is a minimum.
In particular, do not leave the input port open : be sure to input a low-level or high-level signal.
141
CHAPTER 7. STANDBY FUNCTION
7.1 STANDBY MODE SETTING AND OPERATION STATES
Table 7-1 Standby Mode Operation States
STOP Mode
HALT Mode
Setting instruction
Clock generator
STOP instruction
HALT instruction
CPU clock Φ only stopped oscillator
(oscillation continues)
Clock oscillation stopped
Operation
(IRQBT set at basic time interval)
Operation stopped
Basic interval timer
Serial interface
Operation possible
Operation possible only when external
SCK input selected as serial clock
Output other than CPU clock Φ possible
Operation stopped
Clock output circuit
External interrupt
INT2 : Operation possible
INT0 : Operation impossible
CPU
Operation stopped
Interrupt request signal from operable
RESET input
Reset signal
hardware enabled by interrupt enable
flag or RESET input.
The STOP mode is set by STOP instruction and the HALT mode is set by HALT instruction. (The STOP instruction
and HALT instruction set bits 3 and 2 of the PCC respectively.)
Always write an NOP instruction after the STOP instruction or HALT instruction.
When the CPU operation clock is changed by means of the low-order two bits of the PCC, a time lag may be
generated between rewriting of the PCC and changing of the CPU clock. Therefore, when changing the operating
clock before the standby mode and when changing the CPU clock after standby mode reset, set the standby mode
after the number of machine cycles required to change the CPU clock has elapsed after the PCC is rewritten.
In the standby mode, the data of the general register, flags, mode registers, output latch, and all the other registers
which stop operating in the standby mode and the data memory is retained.
Notes are given below.
Note 1. When the STOP mode is set, the X1 pin is shorted internally to VSS (GND potential) to suppress clock
oscillator leakage. Therefore, do not use the STOP mode with systems that use an external clock.
2. STOP mode reset by interrupt request differs as follows for the µPD75402A and the evachip installed
on the evaluation board:
•
•
µPD75402A
Evachip
••••••
STOP mode not reset by interrupt request.
STOP mode reset by interrupt request.
••••••••••••••
To eliminate the affect of this difference, disable all interrupt requests before setting the µPD75402A
to the STOP mode.
3. From the standpoint that an interrupt request signal is used to reset the HALT mode, when there is an
interrupt source which sets both the interrupt request flag and interrupt enable flag (1), the HALT mode,
even if entered, is immediately reset.
142
CHAPTER 7. STANDBY FUNCTION
7.2 STANDBY MODE RESET
The STOP mode is reset only by RESET input. The HALT mode is reset by standby release signal by setting of
an interrupt request flag enabled by the interrupt enable flag and by RESET input.
The standby mode reset operation is shown in Fig. 7-1.
Note When a standby mode (STOP/HALT) was reset by RESET input, theµPD75402A does not insert a wait before
the start of instruction execution. Instruction execution begins simultaneously with resetting of the
standby mode.
(1) STOP mode reset by RESET input
When the RESET input drops from high to low, the oscillator begins to oscillate simultaneously with entry into
the reset state.
When the RESET input level returns from low to high, instruction execution begins even if oscillation is unstable.
Therefore, provide an oscillation stabilization time by making the RESET input low level sufficiently wide.
When the reset state is released, the program branches to the reset start address.
This is different from normal reset operation because the contents of data memory before STOP mode setting
are retained.
(2) HALT mode reset by RESET input
When the RESET input drops from high to low, the HALT mode is reset and the µPD75402A enters the reset state.
When the RESET input level returns from low to high, the program branches to the reset start address and
instruction execution begins.
This is different from the normal reset operation because the contents of data memory before HALT mode setting
are retained.
(3) HALT mode reset by interrupt generation
When an interrupt request flag enabled by interrupt enable flag is set (1), a standby release signal is generated
and the HALT mode is reset. However, the INT0 interrupt request does not generate the standby release signal.
143
CHAPTER 7. STANDBY FUNCTION
Fig. 7-1 Standby Mode Reset Operation
(a) STOP mode reset by RESET input
Oscillation
Stabilization Time
STOP
Instruction
RESET
Input
Operating
Mode
Operating
Mode
STOP Mode
HALT Mode
Oscillation
Oscillation
Stopped
Oscillation
Clock
(b) HALT mode reset by RESET input
HALT
Instruction
RESET
Input
Operating
Mode
HALT Mode
Operating Mode
Oscillation
Clock
(c) HALT mode reset by interrupt generation
2 Instructions
Execution
HALT
Instruction
Standby
Rlease
Signal
Operating
Mode
HALT Mode
Operating Mode
Oscillation
Clock
Remarks The broken line is for the case when an interrupt request that reset the HALT mode was accepted (IME
= 1).
144
CHAPTER 7. STANDBY FUNCTION
7.3 OPERATION AFTER STANDBY MODE RESET
(1) When the standby mode was reset by RESET input, normal reset operation is executed. (STOP and HALT modes)
(2) When the standby mode was reset by interrupt request generation, whether or not a vector interrupt is executed
when the CPU resumes instruction execution is determined by the contents of the interrupt master enable flag
(IME). (HALT mode)
(a) IME = 0
After HALT mode reset, execution is resumed from the instruction (NOP instruction) after the HALT mode
setting instruction.
The interrupt request flag is held.
(b) IME = 1
After HALT mode is reset, a vector interrupt is executed two instructions after the HALT mode setting
instruction. However, because a vector interrupt is not generated when the HALT mode was reset by INT2
(testable input), the same processing as (a) is performed.
7.4 STANDBY MODE APPLICATION
When using the standby mode, proceed as follows:
➀
➁
Power interruption or other standby mode setting cause detection by interrupt input or port input.
I/O port processing (Process for minimum current drain)
In particular, do not leave the input port open : be sure to input a low-level or high-level signal.
Specification of interrupt which resets the standby mode (However, for HALT mode, interrupt enable flags
which is not reset are cleared.)
★
➂
4
Specification of operation after reset (IME is operated according to whether or not interrupt processing
is performed after HALT mode resetting.)
➄
6
Specification of CPU clock after reset (For switching, provide the number of machine cycles necessary up
to standby mode setting.)
Standby mode setting (STOP and HALT instructions)
145
CHAPTER 8. RESET FUNCTION
When low level is input to the RESET pin, system reset is applied and the hardware enters the state shown in
Table 8-1.
When the RESET input goes from low level to high level, the reset state is released. Then, the contents of the
lower-order three bits of address 000H of the reset vector table are set into program counter (PC) bits 10 to 8 and
the contents of the low-order three bits of address 001H are set into PC bits 7 to 0 and the program branches and
begins executing from that branch address. Therefore, reset and starting from an arbitrary address is possible.
Initialize the contents of each register as required in the program.
The RESET pin is a Schmitt-triggered input with hysteresis characteristics at the threshold level. To prevent
misoperation by noise, a function which rejects narrow band noise by analog delay is also provided on the chip
(see Fig. 8-1).
For reset operation at power-on, provide an ample oscillation stabilization time from power-on to reset signal
acceptance as shown in Fig. 8-2.
Fig. 8-1 Reset Signal Acceptance
RESET
Reset branch destination
address instruction
execution
Contents of reset
Analog
Delay
Analog
Delay
Analog
Delay
vector table set
in PC (PC initialize)
Rejected
as Noise
Reset
Acceptance
Reset
Release
Fig. 8-2 Reset at Power-on
V
DD
RESET
Reset branch
destination address
instruction execution
Contents of reset
vector table set
in PC (PC initialize)
Oscillation
Stabilization
Time
Analog
Delay
Reset
Release
146
CHAPTER 8. RESET FUNCTION
Table 8-1 State of Hardware after Reset
RESET Input
standby mode
RESET Input
during operation
Hardware
Low-order 3 bits of
program memory address program memory address
Low-order 3 bits of
Program counter (PC)
000H set in PC10 to PC8
and contents of address
001H set in PC7 to PC0
000H set in PC10 to PC8
and contents of address
001H set in PC7 to PC0
Carry flag (CY)
Skip flag (SK0 to SK2)
Interrupt status flag (IST0)
Retained
Undefined
PSW
0
0
0
Undefined
Retained*
Retained
Undefined
0
0
Stack pointer (SP)
Undefined
Undefined
Data Memory (RAM)
General register (X, A, H, L)
Basic interval timer
Undefined
Counter (BT)
Undefined
Mode register (BTM)
0
Shift register (SIO)
Retained
0
Undefined
Serial interface
Operation mode register (CSIM)
SBI control register (SBIC)
Slave address register (SVA)
0
0
0
Retained
0
Undefined
0
Processor clock control register
(PCC)
Clock generator,
clock output circuit
Clock output mode register
(CLOM)
0
0
Interrupt function
Interrupt request flag (IRQ×××)
Interrupt enable flag (IE×××)
Interrupt master enable flag (IME)
INT0 mode register (IM0)
Output buffer
Reset (0)
Reset (0)
0
0
0
0
0
0
Digital input/output port
OFF
OFF
Output latch
Clear (0)
Clear (0)
I/O mode register (PMGA, PMGB)
0
0
0
0
Pull-up resistor specification
register (POGA)
Pin state
Pin state P00 to P03, P10, P12, P20
to P23, P30 to P33, P60 to P63
Input
Input
P50 to P53
•
•
On-chip pull-up resistor
••••• High level
Open-drain
•
•
On-chip pull-up resistor
••••• High level
Open-drain
••••• High impedance
••••• High impedance
*
The contents of data memory addresses 038H to 03DH are made undefined by RESET input.
147
CHAPTER 9. INSTRUCTION SET
The 75X series instruction set is an improved and expanded version of old µPD7500 series instruction set. It is
a revolutionary new instruction set which retains succession from the µPD7500 series. The µPD75402A instruction
set is a 75X instruction subset, and has the following features:
(1) Multipurpose bit manipulation instruction
(2) Efficient 4-bit manipulation instruction
(3) 8-bit data transfer instruction
(4) Stack instructions and base correction instructions with increase program efficiency
(5) Table reference instructions suitable for continuous reference
(6) 1-byte relative branch instruction
(7) Easy to understand NEC standard mnemonics
For the addressing modes which can be used when operating the data memory, see CHAPTER 3 “FEATURES OF
ARCHITECTURE AND MEMORY MAP”.
148
CHAPTER 9. INSTRUCTION SET
9.1 SPECIAL INSTRUCTIONS
This section outlines the special instructions of the µPD75402A instruction set.
9.1.1 Bit Manipulation Instructions
µPD75402A bit manipulation can be performed by various instructions, such as the following:
(a) Bit set
:
SET1
SET1
CLR1
CLR1
SKT
mem. bit
fmem. bit
mem. bit
fmem. bit
mem. bit
fmem. bit
mem. bit
fmem. bit
(b) Bit clear:
(c) Bit test :
(d) Bit test :
SKT
SKF
SKF
(e) Bit test & clear :
SKTCLR fmem. bit
(f) Boolean operation:
AND1
OR1
CY, fmem. bit
CY, fmem. bit
CY, fmem. bit
XOR1
fmem. bit is the bit address specified by special address bit manipulation addressing.
Especially, since I/O ports can always use all the bit manipulation instructions above, I/O port operation can be
performed very efficiently.
9.1.2 Stack Instructions
The following two kinds of stack instructions are available with the µPD75402A.
(a) MOV A, #n4 or MOV XA, #n8
(b) MOV HL, #n8
“Stack” signifies that these two kinds of instructions are placed in contiguous addresses.
Example A0 : MOV A,
#0
#1
A1 : MOV A,
XA7: MOV XA, #07
When stack instructions are stacked such as in the example above, when the address executed first is A0, it is
executed by replacing the next two instructions with NOP instructions. When the address executed first is A1, it is
executed by replacing the next instruction with an NOP instruction. That is, only the instruction executed first is
effective, all the stack instructions following it are processed as NOP instructions.
Constants can be efficiently set to accumulator (A register, register pair XA) and data pointer (register pair HL)
by using these stack instructions.
149
CHAPTER 9. INSTRUCTION SET
9.1.3 Base Correction Instructions
Depending on the application, the result of addition of 4-bit data must be converted to decimal numbers or to
base-6, such as time.
Base correction instructions for converting the result of addition of 4-bit data to an arbitrary base are available
with the µPD75402A instruction set.
(a) Base correction at addition
If the base value to be corrected is made m, accumulator and memory (HL) are added and the sum is converted
to base-m by combination:
-
ADDS A, #16 m
ADDC A, @HL
ADDS A, #m
; A, CY ← A + (HL) + CY
Overflow remains in the carry flag.
When a carry is output as a result of execution of the ADDC A, @HL instruction, the following ADDS A, #n4
instruction is skipped. If carry is not output, the ADDS A, #n4 instruction is executed. At this time, this instruction
skip function is disabled and the next instruction is not skipped even if carry is output as the result of addition.
Therefore, the program can continue after the ADDS A, #n4 instruction.
Example Decimal add accumulator and memory.
ADDS
ADDC
ADDS
A, #6
A, @HL
A, #10
; A, CY ← A + (HL) + CY
•
•
•
9.1.4 Skip Instruction and Number of Machine Cycles Required by Skip
With the µPD75402A instruction set, a program is formed by condition judgment by skip.
If the skip condition is satisfied when a skip instruction is executed, the following instruction is skipped and the
instruction after the instruction is executed.
When a skip was generated, one machine cycle is required to skip.
150
CHAPTER 9. INSTRUCTION SET
9.2 INSTRUCTION SET AND ITS OPERATION
(1) Operation identifier and description
The operands are described in the operand field of each instruction in accordance with the description for the
operand identifier of the instruction. (See "RA 75X Assembler Package User's Manual Language Volume (EEU-730)
for details.) For parameters with multiple elements in the description, one of the elements is selected. Upper case
letters and the symbols #, @, !, and $ are key words and described unchanged.
For immediate data, a suitable value or label is described.
Instead of mem, fmem, bit, etc., various kinds of registers and flag symbols shown in Table 3-4 can be written
as labels (however, in the case of fmem there are restrictions on the labels that can be written. See Table 3-3
"Applicable Addressing Modes at Peripheral Hardware Operation" and Table 3-4" µPD75402A I/O Map" for details.
Identifier
Description
reg
X, A, H, L
X, H, L
reg1
rp
XA, HL
n4
4-bit immediate data or label
8-bit immediate data or label
8-bit immediate data or label*
2-bit immediate data or label
FB0H to FBFH, FF0H to FFFH immediate data or label
11-bit immediate data or label
11-bit immediate data or label
11-bit immediate data or label
PORT0 to PORT3, PORT5, PORT6
IEBT, IECSI, IE0, IE2
n8
mem
bit
fmem
addr
caddr
faddr
PORTn
IE×××
*
For 8-bit data processing, mem can describe even address only.
(2) Operation description legend
A
: A register; 4-bit accumulator
H
: H register
L
: L register
X
: X register
XA
HL
: Register pair (XA); 8-bit accumulator
: Register pair (HL)
PC
: Program counter
SP
: Stack pointer
CY
: Carry flag; bit accumulator
: Program status word
: Port n (n = 0 to 3, 5, 6)
: Interrupt master enable flag
: Interrupt enable flag
: Processor clock control register
: Address, bit delimiter
: Contents addressed by ××
: Hexadecimal data
PSW
PORTn
IME
IE×××
PCC
.
( ×× )
××H
151
CHAPTER 9. INSTRUCTION SET
(3) Description of addressing area field symbols
* 1
MB = 0
* 2
MB = 0 (00H to 3FH)
Data memory
addressing
MB = 15 (80H to FFH)
* 3
MB = 15, fmem = FB0H to FBFH,
FF0H to FFFH
* 4
addr = 000H to 77FH
* 5
addr = (Current PC) – 15 to (Current PC) – 1,
(Current PC) + 16 to (Current PC) + 2
caddr = 000H to 77FH
Program memory
addressing
* 6
* 7
faddr = 000H to 77FH
Remarks 1. MB is the accessible memory bank.
2. *4 to *7 are the addressable areas.
(4) Description of machine cycle field
S is the number of machine cycles required when the skip operation is performed by an instruction with skip.
The value of S changes as follows:
• Do not skip next instruction ..... S = 0
• Skip next instruction ................. S = 1
One machine cycle equals one cycle of CPU clock Φ. Three times can be selected by PCC setting. (See section
5.2.2(1).)
152
CHAPTER 9. INSTRUCTION SET
Machine
Addressing
Area
Skip
Note 1
Bytes
Operation
Mnemonic
Operand
A, #n 4
Cycle
Condition
1
2
2
1
1
2
2
2
2
1
2
2
1
1
1
1
1
1
1
1
1
2
1
2
1
2
1
1
1
1
1
1
2
2
1
1
2
2
2
2
1
2
2
1
3
A ← n 4
Stack A
Stack A
Stack B
XA, #n 8
HL, #n 8
A, @HL
@HL, A
A, mem
XA, mem
mem, A
mem, XA
A, @HL
A, mem
XA, mem
A, reg1
XA, @PCXA
A, #n 4
A, @HL
A, @HL
A. @HL
A, @HL
A, @HL
A
XA ← n 8
HL ← n 8
A ← (HL)
(HL) ← A
A ← (mem)
*1
*1
*2
*2
*2
*2
*1
*2
*2
MOV
XA ← (mem)
(mem) ← A
(mem) ← XA
A ↔ (HL)
A ↔ (mem)
XCH
XA ↔ (mem)
A ↔ reg1
MOVT
ADDS
XA ← (PC10 – 8 + XA) ROM
A ← A + n 4
1 + S
carry
carry
1 + S
A ← A + (HL)
A, CY ← A + (HL) + CY
A ← A ∧ (HL)
A ← A ∨ (HL)
A ← A ∨ (HL)
CY ← A0, A3 ← CY, An–1 ← An
A ← A
*1
*1
*1
*1
*1
ADDC
AND
OR
1
1
1
XOR
RORC
NOT
1
1
A
2
reg
1 + S
2 + S
1 + S
2 + S
1 + S
1
reg ← reg + 1
(mem) ← (mem) + 1
reg ← reg – 1
Skip if reg = n 4
Skip if A = (HL)
CY ← 1
reg = 0
INCS
mem
*2
*1
(mem) = 0
reg = FH
reg = n4
A = (HL)
DECS
reg
reg, #n 4
A, @HL
CY
SKE
SET 1
CLR 1
SKT
CY
1
CY ← 0
CY
1 + S
1
Skip if CY = 1
CY ← CY
CY = 1
NOT 1
CY
Note 1. Instruction Group
2. Accumulator operation instructions
3. Increment/decrement instructions
4. Compare instructions
153
CHAPTER 9. INSTRUCTION SET
Machine
Addressing
Area
Skip
Note
Bytes
Operation
(mem. bit) ← 1
Mnemonic
Operand
mem. bit
Cycle
Condition
2
2
2
2
2
2
2
2
2
2
2
2
–
2
2
2
2
*2
*3
*2
*3
*2
*3
*2
*3
*3
*3
*3
*3
*4
SET 1
CLR 1
SKT
f mem. bit
mem. bit
(f mem.bit) ← 1
(mem. bit) ← 0
f mem. bit
mem. bit
(f mem. bit) ← 0
2 + S
Skip if (mem. bit) = 1
Skip if (f mem. bit) = 1
Skip if (mem. bit) = 0
Skip if (f mem. bit) = 0
Skip if (f mem. bit) = 1 and clear
CY ← CY ∧ (f mem. bit)
CY ← CY ∨ (f mem. bit)
CY ← CY ∨ (f mem. bit)
PC 10 – 0 ← addr
(mem. bit) = 1
(f mem. bit) = 1
(mem. bit) = 0
(f mem. bit) = 0
(f mem. bit) = 1
f mem. bit
mem. bit
2 + S
2 + S
2 + S
2 + S
2
SKF
f mem. bit
f mem. bit
CY, f mem. bit
CY, f mem. bit
CY, f mem. bit
addr
SKTCLR
AND 1
OR 1
2
XOR 1
2
–
The assembler selects the opti-
mum instruction from among
BR
(
)
BRCB!, caddr, and BR$ addr.
$addr
1
2
2
2
PC 10 – 0 ← addr
*5
*6
BRCB
! caddr
PC 10 – 0 ← caddr
(SP–4) (SP –1) (SP–2) ← 0, PC 10 – 0
(SP – 3) ← 0000
CALLF
! faddr
2
1
1
2
3
*7
PC 10 – 0 ← faddr, SP ← SP – 4
PC 10 – 0 ← (SP) (SP + 3) (SP + 2)
SP ← SP + 4
RET
PC 10 – 0 (SP) (SP + 3) (SP + 2)
SP ← SP + 4,
RETS
3 + S
None
then skip unconditionally
PC 10 – 0 ← (SP) (SP + 3) (SP + 2)
PSW ← (SP + 4) (SP + 5),
SP ← SP + 6
RETI
1
3
PUSH
POP
rp
rp
1
1
2
2
2
2
1
1
2
2
2
2
(SP–1) (SP–2) ← rp, SP ← SP–2
rp ← (SP + 1) (SP) , SP ← SP + 2
IME (IPS. 3) ← 1
EI
IE×××
IE××× ← 1
IME (IPS. 3) ← 0
DI
IE×××
IE××× ← 0
Note Instruction Group
154
CHAPTER 9. INSTRUCTION SET
Machine
Addressing
Area
Skip
Bytes
Operation
Mnemonic
Operand
Note 1
Cycle
Condition
IN
A, PORTn
PORTn, A
2
2
2
2
1
2
2
2
2
1
A ← PORTn (n = 0 – 3, 5, 6)
PORTn ← A (n + 2, 3, 5, 6)
Set HALT Mode (PCC.2 ← 1)
Set STOP Mode (PCC.3 ← 1)
No Operation
OUT
HALT
STOP
NOP
Note 1. Instruction Group
2. I/O instructions
155
CHAPTER 9. INSTRUCTION SET
9.3 OPERATION CODE OF EACH INSTRUCTION
(1) Description of operation code symbols
R1
0
R0
0
reg
A
P1
0
reg-pair
XA
rp
0
1
X
1
HL
reg
1
0
L
reg 1
1
1
H
N2
0
N1
0
N0
0
IE×××
IEBT
IECSI
IE0
1
0
1
1
1
0
1
1
1
IE2
In : Immediate data for n4, n8
Dn : Immediate data for mem
Bn : Immediate data for bit
Nn : Immediate data for n, IE×××
An : Immediate data for [relative address distance with branch address (2 to 16)] - 1
Sn : Immediate data for one’s complement of [relative address distance with branch address (15 to 1)]
(2) Bit manipulation addressing operation code
bit-addr of the second byte of the operation code of an instruction with fmem. bit at the operands is shown below.
bit-addr
Accessible bits
Operable bits of FB0H to FBFH
Operable bits of FF0H to FFFH
1
1
0
1
B1
B1
B0
B0
F3
F3
F2
F2
F1
F1
F0
F0
Bn : Immediate data for bit address (0 to 3) described at bit
Fn : Immediate data for low-order four bits of address described at fmem
156
CHAPTER 9. INSTRUCTION SET
Operation Code
Mnemonic
Note 1
Operand
B1
B2
A, #n 4
0
1
1
1
1
1
1
1
1
1
1
1
1
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
1
1
0
0
0
0
1
0
0
1
1
1
1
0
0
0
0
0
0
1
0
1
0
0
1
1
1
1
1
0
1
1
1
1
0
0
1
1
1
0
0
1
0
1
0
1
1
0
0
0
0
0
0
0
1
1
0
0
1
0
0
0
0
0
1
1
0
1
1
1
1
0
1
0
1
0
1
1
1
0
0
0
1
0
0
0
1
1
I3
1
0
1
0
0
0
0
1
0
0
1
0
I3
0
1
0
0
0
1
1
0
0
1
1
0
0
0
0
0
I2
0
0
0
0
0
0
0
0
0
0
0
0
I2
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
I1
P1
0
I0
1
rp, #n 8
A, @HL
@HL, A
A,mem
XA, mem
mem, A
mem, XA
A, @HL
A, mem
XA, mem
A, reg1
XA, @PCXA
A, #n 4
A, @HL
A, @HL
A, @HL
A, @HL
A, @HL
A
I7
I6
I5
I4
I3
I2
I1
I0
1
0
0
MOV
1
1
D7
D7
D7
D7
D6
D6
D6
D6
D5
D5
D5
D5
D4
D4
D4
D4
D3
D3
D3
D3
D2
D2
D2
D2
D1
D1
D1
D1
D0
0
1
0
1
1
D0
0
1
0
0
1
1
1
D7
D6
D6
D5
D5
D4
D4
D3
D3
D2
D2
D1
D1
D0
XCH
1
0
D7
0
R1
0
R0
0
MOVT
ADDS
I1
1
I0
0
ADDC
AND
OR
0
1
0
0
0
0
XOR
RORC
NOT
0
0
0
0
A
0
1
0
D7
I7
1
D6
I6
0
D5
I5
1
D4
I4
1
D3
0
1
D2
0
1
1
reg
R1
1
R0
0
INCS
DECS
SKE
mem
D1
R1
D0
R0
reg
R1
1
R0
0
reg, #n 4
A, @HL
CY
0
0
SET 1
CLR 1
SKT
1
1
CY
1
0
CY
1
1
NOT 1
CY
1
0
Note 1. Instruction Group
2. Accumulator operation instructions
3. Increment/decrement instructions
4. Compare instruction
157
CHAPTER 9. INSTRUCTION SET
Operation Code
Note 1 Mnemonic
Operand
B1
B2
mem. bit
1
1
1
1
1
1
1
1
1
1
1
1
0
1
0
0
1
1
1
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
B1
0
B0
1
0
1
0
1
0
1
0
1
1
1
1
1
A3
S3
0
0
1
0
1
1
1
1
1
1
1
0
0
1
1
0
1
1
0
0
1
1
D7
D7
D7
D7
D6
D6
D6
D6
D5
D5
D5
D5
D4
D3
D3
D3
D3
D2
D2
D2
D2
D1
D1
D1
D1
D0
D0
D0
0
SET 1
f mem. bit
mem. bit
bit-addr
D4
B1
0
B0
1
1
0
0
CLR 1
SKT
f mem. bit
mem. bit
1
0
0
bit-addr
D4
B1
1
B0
1
1
1
1
f mem. bit
mem. bit
1
1
1
bit-addr
D4
B1
1
B0
1
1
1
0
SKF
f mem. bit
f mem. bit
CY, f mem. bit
CY, f mem. bit
CY, f mem. bit
1
1
0
bit-addr
bit-addr
bit-addr
bit-addr
bit-addr
SKTCLR
AND 1
OR 1
0
1
1
1
1
1
0
1
0
0
1
0
1
1
0
XOR 1
1
1
1
0
0
(+16)
0
0
A2
S2
A1
S1
A0
S0
(+ 2)
(– 1)
BR
$addr
1
1
(–15)
BRCB
CALLF
RET
! caddr
! faddr
0
1
caddr
faddr
0
0
1
0
1
0
1
0
0
1
1
1
1
0
0
1
1
0
1
0
0
0
1
1
0
1
1
0
0
1
1
1
1
0
RETS
RETI
1
0
1
0
1
PUSH
POP
rp
rp
0
0
P1
P1
0
0
0
0
1
1
1
1
1
1
1
1
1
0
0
0
0
1
1
0
0
1
0
1
0
1
1
1
1
1
1
1
1
1
1
0
1
0
1
0
1
0
0
0
0
0
N2
0
1
N1
1
0
N0
0
EI
IE×××
0
1
0
0
1
0
DI
IE×××
0
1
0
N2
N2
N2
0
N1
N1
N1
1
N0
N0
N0
1
IN
A, PORTn
PORTn, A
1
0
1
OUT
HALT
STOP
NOP
0
1
1
0
1
0
0
1
0
0
1
1
1
0
0
Note 1. Instruction Group
2. Branch instructions
3. I/O instructions
4. CPU control instructions
158
CHAPTER 9. INSTRUCTION SET
9.4 INSTRUCTION FUNCTIONS AND APPLICATION
9.4.1 Move Instructions
MOV A, #n4
Function: A ← n4; n4 = I3 to I0 : 0 to FH
Moves 4-bit immediate data n4 to the A register (4-bit accumulator).
This instruction has a stacking effect (group A). When placed after a MOV A, #n4 or MOV XA, #n8 instruction,
stack instructions following the executed instruction are processed as NOP.
Application examples: ➀ Set 0BH into accumulator.
MOV A, #0BH
➁ Select the data to be output at Port 3 from 0 to 2.
A0: MOV A, #0
A1: MOV A, #1
A2: MOV A, #2
OUT PORT 3, A
MOV rp, #n8
Function: rp ← n8; n8 = I7 to I0 : 00H to FFH
Moves 8-bit immediate data n8 to register pair rp (XA, HL).
This instruction has a stacking effect. There are two stacking effects: Group A (MOV A, #n4 instruction and
MOV XA, #n8 instruction), and group B (MOV HL, #n8 instruction). When instructions of the same group are
placed consecutively, the stack instructions after the executed instruction are processed as NOP.
Application example: Set 5FH into register pair HL.
MOV HL, #5FH
MOV A, @HL
Function: A ← (HL)
Moves the data memory contents addressed by the contents of register pair HL to the A register.
Application example: Move the data of address 3EH to the A register.
MOV HL, #3EH
MOV A, @HL
159
CHAPTER 9. INSTRUCTION SET
MOV @HL, A
Function: (HL) ← A
Moves the contents of the A register to the data memory addressed by the contents of register pair HL.
MOV A, mem
Function: A ← (mem); mem = D7 to D0 : 00H to 3FH
Moves the data memory contents addressed by 8-bit immediate data mem to the A register.
MOV XA, mem
Function: A ← (mem), X ← (mem + 1); mem = D7 to D0 : 00H to 3EH
Moves the data memory contents addressed by 8-bit immediate data mem to the A register and the contents
of the next address to the X register.
mem can specify even addresses.
Application example: Move the data of addresses 20H and 21H to register pair XA.
MOV XA, 20H
MOV mem, A
Function: (mem) ← A; mem = D7 to D0 : 00H to 3FH
Move the contents of the A register to the data memory addressed by 8-bit immediate data mem.
MOV mem, XA
Function: (mem) ← A, (mem + 1) ← X; mem = D7 to D0 : 00H to 3EH
Moves the contents of the A register to the data memory addressed by 8-bit immediate data mem and the
contents of the X register to the next memory address.
mem can specify even addresses.
160
CHAPTER 9. INSTRUCTION SET
XCH A, @HL
Function: A ← (HL)
Exchanges the contents of the A register and the contents of the data memory addressed by the contents
of register pair HL.
Application example: Exchange the data of data memory addresses 20H to 2FH and the data of addresses 30H
to 3FH.
MOV HL, #30H
LOOP: XCH A, @HL
MOV H, #2
; A ↔ (3×)
XCH A, @HL
MOV H, #3
; A ↔ (2×)
XCH A, @HL
INCS L
; A ↔ (3×)
; L ← L + 1
BR
LOOP
XCH A, mem
Function: A ↔ (mem); mem = D7 to D0 ; 00H to 3FH
Exchanges the contents of the A register and the data memory contents addressed by 8-bit immediate data
mem.
XCH XA, mem
Function: A ↔ (mem), X ↔ (mem + 1); mem = D7 to D0 : 00H to 3EH
Exchanges the contents of the A register and the data memory contents addressed by 8-bit immediate data
mem and exchanges the contents of the X register and the contents of the next memory address.
mem can specify even addresses.
XCH A, reg1
Function: A ↔ reg1
Exchanges the contents of the A register and the contents of register reg1 (X, H, L).
161
CHAPTER 9. INSTRUCTION SET
9.4.2 Table Reference Instructions
MOVT XA, @PCXA
Function: XA ← ROM (PC10 to PC8 + XA)
Moves the high-order three bits (PC10 to PC8 ) of the program counter (PC) and the low-order four bits of
the table data in the program memory addressed by the contents of register pair XA to the A register and the
high-order four bits to the X register.
The high-order three bits of the table address are determined by the contents of the grogram counter (PC)
when this instruction is executed.
The necessary data must be preprogrammed at the table area by assembler pseudo instruction (DB
instruction).
The program counter is not affected by execution of this instruction.
This instruction is effective when referencing table data consecutively.
Program Memory
12
8
7
4 3
0
7
4
3
0
Table
Table
Data H
Table
Data L
A 3–0
PC 12–8
X 3–0
Address
3
0
3
0
▼
▼
X
X
Note The MOVT XA, @PCXA instruction usually references the table data of the page containing the instruction.
However, when the instruction is at address ×FFH, the table data of the next page is referenced instead of
the table data on that page.
Program Memory
7
0
Page2
▼
➀
02FFH
0300H
▼
Page3
For instance, when there is a MOVT XA, @PCXA instruction at position ➀in the figure above, the table data
specified by the contents of register pair XA of page 3 instead of page 2 is moved to register pair XA.
162
CHAPTER 9. INSTRUCTION SET
9.4.3 Arithmetic and Logic Instructions
ADDS A, #n4
Function: A ← A + n4; Skip if carry; n4 = I3 to I0 : 0 to FH
Binary adds 4-bit immediate data n4 to the contents of the A register and skips the next instruction if a carry
is generated. The carry flag is not affected.
When combined with an ADDC A, @HL instruction, this instruction becomes a base correction instruction.
(See section 9.1.)
ADDS A, @HL
Function: A ← A + (HL); Skip if carry
Binary adds the data memory contents addressed by register pair HL to the contents of the A register and
skips the next instruction if a carry is generated. The carry flag is not affected.
ADDC A, @HL
Function: A, CY ← A + (HL) + CY
Binary adds the data memory contents addressed by register pair HL to the contents of the A register,
including the carry flag. If a carry is generated, the carry flag is set. If a carry is not generated, the carry flag
is reset.
When an ADDS A, #n4 instruction is placed after this instruction, when a carry is generated at this instruction,
the ADDS A, #n4 instruction is skipped. When a carry is not generated, the ADDS A, #n4 instruction is executed
and the skip function of the ADDS A, #n4 instruction is disabled. Therefore, the combination of these
instructions can be used in base correction (see section 9.1).
AND A, @HL
Function: A ← A ∧ (HL)
ANDs the contents of the A register and the data memory contents addressed by register pair HL and sets
the result into the A register.
163
CHAPTER 9. INSTRUCTION SET
OR A, @HL
Function: A ← A ∨ (HL)
ORs the contents of the A register and the data memory contents addressed by register pair HL and sets
the result into the A register.
XOR A, @HL
Function: A ← A ∨ (HL)
Exclusive-ORs the contents of the A register and the data memory contents addressed by register pair HL
and sets the result into the A register.
164
CHAPTER 9. INSTRUCTION SET
9.4.4 Accumulator Operation Instructions
RORC A
Function: CY ← A0 An to A1 ← An , A3 ← CY (n = 1 to 3)
Rotates the contents of the A register (4-bit accumulator), including the carry flag, to the right one bit at a
time.
A
CY
0
3
0
2
1
1
0
0
1
Before
Execution
RORC A
After
Execution
1
0
0
1
0
NOT A
Function: A ← A
Takes the one’s complement (inverts each bit) of the A register (4-bit accumulator).
165
CHAPTER 9. INSTRUCTION SET
9.4.5 Increment/Decrement Instructions
INCS reg
Function: reg ← reg + 1; Skip if reg = 0
Increments the contents of register reg (X, A, H, L). When the contents of register reg become 0 as the result
of incrementing, skips the next instruction.
INCS mem
Functions: (mem) ← (mem) + 1; Skip if (mem) = 0, mem = D7 to D0 : 00H to FFH
Increments the data memory contents addressed by 8-bit immediate data mem. When the data memory
contents become 0 as a result of incrementing, skips the next instruction.
DECS reg
Function: reg ← reg - 1; Skip if reg = FH
Decrements the contents of register reg (X, A, H, L). When the contents of register reg become FH as a result
of decrementing, skips the next instruction.
166
CHAPTER 9. INSTRUCTION SET
9.4.6 Compare Instructions
SKE reg, #n4
Function: Skip if reg = n4; n4 = I3 to I0 : 0 to FH
If the contents of register reg (X, A, H, L) equal 4-bit immediate data n4, skips the next instruction.
SKE A, @HL
Function: Skip if A = (HL)
If the contents of the A register and the data memory contents addressed by register pair HL, skips the next
instruction.
167
CHAPTER 9. INSTRUCTION SET
9.4.7 Carry Flag Operation Instructions
SET1 CY
Function: CY ← 1
Sets the carry flag.
CLR1 CY
Function: CY ← 0
Clears the carry flag.
SKT CY
Function: Skip if CY = 1
When the carry flag is 1, skips the next instruction.
NOT1 CY
Function: CY ← CY
Inverts the carry flag. If the carry flag is 0, it becomes 1 and if it is 1, it becomes 0.
168
CHAPTER 9. INSTRUCTION SET
9.4.8 Bit Manipuration Instructions
SET1 mem. bit
Function: (mem. bit) ← 1; mem = D7 to D0 : 00H to 3FH, bit = B1 to B0 : 0 to 3
Sets the bit specified by 2-bit immediate data bit of the address specified by 8-bit immediate data mem.
SET1 fmem. bit
Function: (bit specified by operand) ← 1
Sets the data memory bit specified by bit manipulation addressing (fmem. bit).
CLR1 mem. bit
Function: (mem. bit) ← 0; mem = D7 to D0 : 00H to 3FH, bit = B1 to B0 : 0 to 3
Clears the bit specified by 2-bit immediate data bit of the address specified by 8-bit immediate data mem.
CLR1 fmem. bit
Function: (bit specified by operand) ← 0
Clears the data memory bit specified by bit manipulation addressing (fmem. bit).
SKT mem. bit
Function: Skip if (mem. bit) = 1; mem = D7 to D0 : 00H to 3FH, bit = B1 to B0 : 0 to 3
If 2-bit immediate data bit of the address specified by 8-bit immediate data mem is 1, skips the next
instruction.
SKT fmem. bit
Function: Skip if (bit specified by operand) = 1
If the data memory bit specified by bit manipulation addressing (fmem. bit) is 1, skips the next instruction.
169
CHAPTER 9. INSTRUCTION SET
SKF mem. bit
Function: Skit if (mem. bit) = 0; mem = D7 to D0 : 00H to 3FH, bit = B1 to B0 : 0 to 3
If the bit specified by 2-bit immediate data bit of the address specified by 8-bit immediate data mem is 0,
skips the next instruction.
SKF fmem. bit
Function: Skip if (bit specified by operand) = 0
If the contents of the data memory bit specified by bit manipulation addressing (fmem. bit) is 0, skips the
next instruction.
SKTCLR fmem. bit
Function: Skip if (bit specified by operand) = 1 then clear
If the data memory bit specified by bit manipulation addressing (fmem. bit) is 1, skips the next instruction
and clears that bit to 0.
AND1 CY, fmem. bit
Function: CY ← CY ∧ (bit specified by operand)
ADDs the contents of the carry flag and the contents of the data memory bit specified by bit manipulation
addressing (fmem. bit) and sets the result into the carry flag.
OR1 CY, fmem. bit
Function: CY ← CY ∨ (bit specified by operand)
ORs the contents of the carry flag and the contents of the data memory bit specified by bit manipulation
addressing (fmem. bit) and sets the result into the carry flag.
XOR1 CY, fmem. bit
Function: CY ← CY ∨ (bit specified by operand)
Exclusive-ORs the contents of the carry flag and the contents of the data memory bit specified by bit
manipulation addressing (fmem. bit) and sets the result into the carry flag.
170
CHAPTER 9. INSTRUCTION SET
9.4.9 Branch Instructions
BR addr
Function: PC10 to PC0 ← addr; addr = 000H to 77FH
Branches to the address addressed by 11-bit immediate data addr.
This instruction is an assembler pseudo instruction. During assembly, the assembler automatically replaces
this instruction with the optimum instruction from among the BRCB !caddr and BR $addr instructions.
BR $addr
Function: PC ← addr; addr = (PC-15) to (PC-1), (PC+2) to (PC+16)
This is a relative branch instruction with a branch range of (-15 to -1) and (+2 to +16) from the current address.
Page boundary and block boundary are not affected.
BRCB !caddr
Function: PC10 to PC0 caddr; caddr = A10 to A0 : 000H to 77FH
Branches to the address addressed by 11-bit immediate data caddr (A10 to A0 ).
171
CHAPTER 9. INSTRUCTION SET
9.4.10 Subroutine Stack Control Instructions
CALLF !faddr
Function: (SP-1) ← PC7 to PC4 , (SP-2) ← PC3 to PC0 ,
(SP-3) ← 0, 0, 0, 0
(SP-4) ← 0, PC10 to PC8 ,
SP ← SP-4, PC ← A10 to A0
faddr = A10 to A0 : 000H to 77FH
Saves the contents of the program counter (PC; return address) to the data memory (stack) addressed by
the stack pointer (SP) and decrements the SP, then branches to the address addressed by 11-bit immediate
data faddr.
The range that can be called is limited to addresses 000H to 77FH (0 to 1919).
RET
Function: PC10 to PC8 ← (SP), PC3 to PC0 ← (SP+2),
PC7 to PC4 ← (SP+3), SP ← SP+4
Restores the contents of the data memory (stack) addressed by the stack pointer (SP) to the program counter
(PC), then increments the contents of the SP.
RETS
Function: PC10 to PC8 ← (SP), PC3 to PC0 ← (SP+2)
PC7 to PC4 ← (SP+3), SP ← SP+4, Then skip unconditionally
Restores the contents of the data memory (stack) addressed by the stack pointer (SP) to the program counter
(PC) and increments the contents of the SP, then skips unconditionally.
RETI
Function: PC10 to PC8 ← (SP), PC3 to PC0 ← (SP+2),
PC7 to PC4 ← (SP+3), PSWL ← (SP+4), PSWH ← (SP+5), SP ← SP+6
Restores the contents of the data memory (stack) addressed by the stack pointer (SP) to the program counter
(PC) and program status word (PSW), then increments the SP.
This instruction is used to return from an interrupt handling routine.
172
CHAPTER 9. INSTRUCTION SET
PUSH rp
Function: (SP-1) ← rpH, (SP-2) ← rpL, SP ← SP-2
Saves the contents of register pair rp (XA, HL) to the data memory (stack) addressed by the stack pointer
(SP), then decrements the SP.
The high-order side (rpH: X, H) of the register pair is saved to the stack addressed by (SP-1) and the low-
order side (rpL: A, L) is saved to the stack addressed by (SP-2).
POP rp
Function: rpL ← (SP), rpH ← (SP+1), SP ← SP+2
Restores the contents of the data memory (stack) addressed by the stack pointer (SP) to register pair rp (XA,
HL), then increments the SP.
The contents of (SP) are restored to the low-order side (rpL: A, L) of the register pair and the contents of (SP+1)
are restored to the high-order side (rpH: X, H).
173
CHAPTER 9. INSTRUCTION SET
9.4.11 Interrupt Control Instructions
EI
Function: IME ← 1
Sets the interrupt master enable flag (1), and enables interrupts. Whether or not interrupts are accepted is
determined by each interrupt enable flag.
EI IEXXX
Function: IE××× ← 1; ××× = N2 to N0
Sets the interrupt enable flag (IE×××) (1), and enables the interrupt. (××× = BT, CSI, 0, 2)
DI
Function: IME ← 0
Resets the interrupt master enable flag and disables interrupts regardless of the contents of each interrupt
enable flag.
DI IEXXX
Function: IE××× ← 0; ××× = N2 to N0
Resets the interrupt enable flag (IE×××) (0), and disables the interrupt. (××× = BT, CSI, 0, 2)
174
CHAPTER 9. INSTRUCTION SET
9.4.12 Input/Output Instructions
IN A, PORTn
Function: A ← PORTn; n = N3 to N0 : 0 to 3, 5, 6
Transfers the contents of the port specified by PORTn (n = 0 to 3, 5, 6) to the A register.
Note Only 0 to 3, 5 or 6 can be specified at n.
Output latch data (output mode) or pin data (input mode) is fetched according to input/output mode
specification.
OUT PORTn, A
Function: PORTn ← A; n = N3 to N0 : 2, 3, 5, 6
Transfers the contents of the A register to the output latch of the port specified by PORTn (n = 2, 3, 5, 6)
Note Only 2, 3, 5, or 6 can be specified at n.
175
CHAPTER 9. INSTRUCTION SET
9.4.13 CPU Control Instructions
HALT
Function: PCC. 2 ← 1
Sets the HALT mode (This instruction sets bit 2 of the processor clock control register.).
Note The instruction following the HALT instruction is made an NOP instruction.
STOP
Function: PCC. 3 ← 1
Sets the STOP mode (This instruction sets bit 3 of the processor clock control register).
Note The instruction following the STOP instruction is made an NOP instruction.
NOP
Function: Expend one machine cycle without performing any operation.
176
APPENDIX A. TABLE OF INSTRUCTION USABLE WITH EVAKIT-75X ONLY
Since EVAKIT-75X (75X series common evaluation board) supports the 75X series functions, it can execute the
following instructions not available with theµPD75402A. Since the µPD75402A and µPD75P402 cannot execute these
instructions even though they can be executed on the EVAKIT, do not use them.
Mnemonic
MOV
Operands
Mnemonic
ADDC
Operands
A, reg
rp’1, XA
XA, rp’
A, reg
reg, A
XA, @HL
@HL, XA
A, @HL
rp’1, XA
XA, rp’
A, reg
reg, A
XA, @HL
@HL, XA
A,#n4
A, @rpa
reg1, A
reg1, #n4
rp’1, XA
XA, rp’
XA, @HL
@HL, XA
A, @rpa
HL, mem
XA, @HL
XA, rp’
SUBS, SUBC
XCH
MOVT
MOV1
XA, @PCDE
XA, @BCDE
XA, @BCXA
AND, OR, XOR
rp’1, XA
XA, rp’
mem, A
A, reg
reg, A
XA, @HL
@HL, XA
rp
CY, fmem. bit
CY, pmem. @L
CY, @H + mem. bit
fmem. bit, CY
pmem. @L, CY
@H + mem. bit, CY
rp’1, XA
ADDS
ROLC
XA, rp’
A
XA, #n8
RORC
INCS
rp
A, reg
rp1
reg, A
@HL
XA, @HL
XA
@HL, XA
DECS
rp’
177
APPENDIX A. TABLE OF INSTRUCTION USABLE WITH EVAKIT-75X ONLY
Mnemonic
NOT1
Operands
Mnemonic
DECS
Operands
fmem. bit
mem
pmem. @L
@HL
@H + mem. bit
!addr
SKE
A, reg
BR
XA, rp’
XA, @HL
@HL, #n4
A, mem
pmem. @L
PCDE
PCXA
BCDE
BCXA
SET1, CLR1,
SKF, SKT,
SKTCLR
CALL
PUSH
POP
IN
!addr
@H + mem. bit
CY, pmem. @L
CY, @H + mem. bit
CY,/fmem. bit
BS
AND1, OR1
BS
XA, PORTn
PORTn, XA
MBn
OUT
SEL
CY,/pmem. @L
CY,/@H + mem. bit
CY, pmem. @L
CY, @H + mem. bit
RBn
XOR1
GETI
taddr
reg : X, A, B, C, D, E, H, L
rp
:
:
XA, BC, DE, HL
rp’
XA, BC, DE, HL, XA’, BC’, DE’, HL’
rpa : HL+, HL-, DE, DL
178
★
APPENDIX B. DEVELOPMENT TOOLS
The following development tools are available for system development using the µPD75402A:
Language Processor
RA75X relocatable assembler
Ordering Code
(Product Name)
Host Machine
PC-9800 series
OS
Supply Medium
3.5-inch 2HD
MS-DOSTM
µS5A13RA75X
µS5A10RA75X
µS7B10RA75X
Ver. 3.30
Ver. 5.00 A*
5-inch 2HD
5-inch 2HC
PC DOSTM
(Ver. 3.1)
IBM PC/ATTM
PROM Writing Tools
PG-1500
This PROM programmer allows programming, in standalone a mode or via operation
from a host computer, of a singlechip microcomputer with on-chip PROM by
connection of the d board provided and a separately available programmer adapter.
It can program typical 256K-bit to 4M-bit PROMs.
PA-75P402CT
PA-75P402GB
PROM programmer adapter for µPD75P402C/CT/GB, used connected to the PG-1500.
...
•
•
PA-75P402CT
PA-75P402GB
For µPD75P402C/CT
...
For µPD75P402GB
PG-1500 controller
Connects PG-1500 and host machine via a serial and parallel interface, and controls
the PG-1500 on the host f machine.
Ordering Code
Host Machine
(Product Name)
Supply Medium
OS
PC-9800 series
IBM PC/AT
MS-DOS
3.5-inch 2HD
µS5A13PG1500
µS5A10PG1500
µS7B10PG1500
Ver. 3.30
Ver. 5.00 A*
5-inch 2HD
5-inch 2HC
PC DOS
(Ver. 3.1)
*
The task swap function, which is provided with Ver.5.00/5.00A, is not available with this software.
Remarks Operation of the relocatable assembler and PG-1500 controller is guaranteed only on the host machines
and operating systems quoted above.
179
APPENDIX B. DEVELOPMENT TOOLS
Debugging Tools
The following in-circuit emulators (IE-75000-R and IE-75001-R) are available as the µPD75402A program
debugging tools.
Their respective system configurations are as follows.
IE-75000-R*1
The IE-75000-R is an in-circuit emulator for hardware/software debugging in develop-
ment of an application system using the 75X series.
Used in combination with an emulation probe.
Connected with a host machine and PROM programmer, the IE- 75000-R can perform
efficient debugging.
IE-75000-R-EM
Emulation board for evaluation of an application system using the 75X series.
Used in combination with the IE-75000-R or IE-75001-R.
Incorporated in the IE-75000-R.
IE-75001-R*2
The IE-75001-R is an in-circuit emulator for hardware/software debugging in develop-
ment of an application system using the 75X series.
Used in combination with the separately available IE-75000-R- EM emulation board
and emulation probe.
Connected with a host machine and PROM programmer, the IE- 75001-R can perform
efficient debugging.
EP-75402C-R
µPD75402AC/75402ACT emulation probe.
Used connected with the IE-75000-R, IE-75001-R or IE-75000-R- EM.
EP-75402GB-R
µPD75402AGB emulation probe.
Used connected with the IE-75000-R, IE-75001-R or IE-75000-R- EM
Provided with the EV-9200G-44, 44-pin conversion socket which facilitates connection
with the target system.
EV-9200G-44
IE control program
Connects the IE-75000-R or IE-75001-R with a host machine via RS-232-C or
Centronics I/F and controls the IE-75000-R or IE-75001-R on the host machine.
Ordering Code
Host Machine
(Product Name)
Supply Medium
OS
PC-9800 series
IBM PC/AT
MS-DOS
3.5-inch 2HD
µS5A13IE75X
µS5A10IE75X
µS7B10IE75X
Ver. 3.30
Ver. 5.50 A*3
5-inch 2HD
5-inch 2HC
PC DOS
(Ver. 3.1)
*
1. Maintenance product
2. IE-75000-R-EM is sold separately.
3. The task swap function, which is provided with Ver.5.00/5.00A, is not available with this software.
Remarks Operation of the IE control program is guaranteed only on the above quoted host machines and
operating systems.
180
Development Tool Configuration
In-Circuit Emulator
Emulation Probe
IE-75000-R
IE-75001-R
EP-75402C-R
EP-75402GB-R
Centronics I/F
*1
IE-75000-R-EM
IE
Control
Program
RS-232-C
Host Machine
PC-9800 Series
IBM PC/AT
(Symbolic
Debugging
Capability)
Target System
*2
PG-1500
Controller
On-chip PROM
Products
PROM Programmer
PG-1500
µ
PD75P402C/CT/GB
Relocatable
Assembler
Programmer Adapter
*
1. The IE-75001-R does not incorporate
the IE-75000-R-EM (Sold separately)
2. EV-9200G-44
PA-75P402CT
PA-75P402GB
APPENDIX C. MASK ROM ORDERING PROCEDURE
When completing the µPD75402A program and ordering the mask ROM, proceed as follows:
➀
Mask ROM order reservation
Provide us with the mask ROM ordering schedule through your dealer or our sales department (If we are
not informed in advance, processing may be delayed.).
➁
Preparation of ordering medium
The medium for mask ROM order is UV-EPROM or 8-inch IBM format floppy disk. When ordered with UV-
EPROM, please prepare three UV-EPROMs with the same contents. (Send the mask options data filled in the
mask option information documents.)
➂
Preparation of the necessary documents
When ordering the mask ROM, please fill in the following documents:
•
•
•
Mask type ROM order form
Mask type ROM order check sheet
Mask option information documents
Send the medium prepared in ➁and the documents described in ➂to us through your special agents or
our sales department by the scheduled order date.
4
Note For details, refer to the infamation document “ROM Code Ordering Method” “Documents No. IEM-834”.
182
APPENDIX D. INSTRUCTION INDEX (ALPHABETIC ORDER)
Instruction
Page
176
165
168
164
170
175
173
173
172
172
172
165
168
169
169
167
167
170
170
168
169
169
170
176
161
161
161
161
164
170
Instruction
A, @HL
A, #n4
Page
163
163
163
163
170
171
171
171
172
168
169
169
166
174
174
174
174
176
175
166
166
160
159
159
160
160
159
160
160
162
ADDC
ADDS
ADDS
AND
AND1
BR
NOP
NOT
NOT1
OR
A
A, @HL
A, @HL
CY, fmem. bit
addr
CY
A, @HL
CY, fmem. bit
PORTn, A
rp
OR1
OUT
POP
BR
$addr
BRCB
CALLF
CLR1
CLR1
CLR1
DECS
DI
! caddr
! faddr
CY
PUSH
RET
rp
RETI
RETS
RORC
SET1
SET1
SET1
SKE
fmem. bit
mem. bit
reg
A
CY
fmem. bit
mem. bit
A, @H
DI
IE×××
EI
EI
IE×××
SKE
reg, #n4
fmem. bit
mem. bit
CY
HALT
IN
SKF
A, PORTn
mem
SKF
INCS
INCS
MOV
MOV
MOV
MOV
MOV
MOV
MOV
MOV
MOVT
SKT
reg
SKT
fmem. bit
mem. bit
fmem. bit
A, mem
A, #n4
SKT
SKTCLR
STOP
XCH
XCH
XCH
XCH
XOR
XOR1
A, @HL
mem, A
mem, XA
rp, #n8
A, @HL
A, mem
A, reg1
XA, mem
@HL, A
XA, @PCXA
XA, mem
A, @HL
CY, fmem. bit
183
APPENDIX E. HARDWARE INDEX (ALPHABETIC ORDER)
Hardware
Name
Hardware
Name
Page
Page
Symbol
Symbol
ACKD Acknowledge detect flag
ACKE Acknowledge enable flag
ACKT Acknowledge trigger bit
80, 104, IRQ2
109
80, 104, IRQBT
108
INT2 interrupt request flag
BT interrupt request flag
129
129
129
133
31
79, 104,
107
IRQCS Serial interface interrupt request flag
80, 105,
109
BSYE
BT
Sync busy enable bit
IST0
PC
Interrupt status flag
66
67
64
Basic interval timer
Program counter
55
BTM
Basic interval timer mode register
PCC
Processor clock control mode register
47
CLOM Clock output mode register
CMDD Command detect flag
CMDT Command trigger bit
PMGA, Port mode register (A, B)
PMGB
79,104,
106
51
42
POGA Pull-up resistor specification register
79, 87,
103,106
PORT 0 Port 0 to 3, 5, 6
to 3,
5, 6
76, 86,
102
COI
Address comparator coincidence signal
76, 83,
86,102
CSIE
Serial interface operation enable/disable
specification bit
39
PSW
Program status word
Bus release detect flag
79, 104,
106
79, 87,
103,106
78, 87,
103,106
to 109
73, 81,
113
RELD
73, 74,
85, 101
39
CSIM
CY
Serial operating mode register
Carry flag
RELT
SBIC
Bus release trigger bit
Serial bus interface control register
129
129
129
129
131
132
129
IE0
INT0 interrupt enable flag
INT2 interrupt enable flag
BT interrupt enable flag
Serial interface interrupt enable flag
INT0 mode register
IE2
SIO
Serial I/O shift register
IEBT
IECSI
IM0
IME
IRQ0
40
SK0 to Skip flag
SK2
37
SP
Stack pointer
73, 82,
113
76, 85,
102
SVA
WUP
Slave address register
Interrupt master enable flag
INT0 interrupt request flag
Wake-up function specification bit
184
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