4280 Datasheet, PDF (23/48 Pages) Renesas Technology Corp – SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER for INFRARED REMOTE CONTROL TRANSMITTERS

MITSUBISHI MICROCOMPUTERS
4280 Group
SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER for INFRARED REMOTE CONTROL TRANSMITTERS
SYMBOL
The symbols shown below are used in the following list of instruction function and the machine instructions.
Symbol
A
B
DR
ER
C
V1
PU0
LO
X
Y
DP
PC
PCH
PCL
SK
SP
CY
R1
T1
T1F
WDT
WDF1
WDF2
URS
P
STCK
INSTCK
Contents
Symbol
Register A (4 bits)
D
Register B (4 bits)
E
Register D (3 bits)
G
Register E (8 bits)
CARR
Carrier wave selection register C (3 bits)
Timer control register V1 (3 bits)
x
Pull-down control register PU0 (3 bits)
y
Logic operation selection register LO (2 bits)
p
n
Register X (2 bits)
Register Y (4 bits)
j
Data pointer (6 bits)
(It consists of registers X and Y)
A3A2A1A0
Program counter (10 bits)
High-order 3 bits of program counter
Low-order 7 bits of program counter
←
Stack register (10 bits ! 4)
↔
Stack pointer (2 bits)
?
Carry flag
()
Timer 1 reload register
—
Timer 1
Timer 1 underflow flag
M(DP)
Watchdog timer
a
Watchdog timer flag 1
p, a
Watchdog timer flag 2
Most significant ROM code reference enable flag C
Power down flag
+
System clock
x
Instruction clock
Contents
Port D (8 bits)
Port E (3 bits)
Port G (4 bits)
Port CARR (1 bit)
Hexadecimal variable
Hexadecimal variable
Hexadecimal variable
Hexadecimal constant which represents the
immediate value
Hexadecimal constant which represents the
immediate value
Binary notation of hexadecimal variable A
(same for others)
Direction of data movement
Data exchange between a register and memory
Decision of state shown before “?”
Contents of registers and memories
Negate, Flag unchanged after executing
instruction
RAM address pointed by the data pointer
Label indicating address a6 a5 a4 a3 a2 a1 a0
Label indicating address a6 a5 a4 a3 a2 a1 a0
in page p3 p2 p1 p0
Hex. number C + Hex. number x (also same for
others)
Note : The 4280 Group just invalidates the next instruction when a skip is performed. The contents of program counter is not
increased by 2. Accordingly, the number of cycles does not change even if skip is not performed. However, the cycle count
becomes “1” if the TABP p, RT, or RTS instruction is skipped.
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