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APPENDIX
Appendix 6. Machine instructions
7721 Group User’s Manual
17–55
Symbols in machine instructions table
Symbol
IMP
IMM
A
DIR
DIR, b
DIR, X
DIR, Y
(DIR)
(DIR,X)
(DIR), Y
L (DIR)
L (DIR),Y
ABS
ABS, b
ABS, X
ABS, Y
ABL
ABL, X
(ABS)
L (ABS)
(ABS, X)
STK
REL
DIR, b, REL
ABS, b, REL
SR
(SR), Y
Stack pointer relative indirect indexed Y
addressing mode
Block transfer addressing mode
Carry flag
Zero flag
Interrupt disable flag
Decimal operation mode flag
Index register length selection flag
Data length selection flag
Overflow flag
Negative flag
Processor interrupt priority level
Addition
Subtraction
Multiplication
Division
Logical AND
Logical OR
∨
Description
Symbol
Description
BLK
C
Z
I
D
x
m
V
N
IPL
+
–
8
/
∧
Implied addressing mode
Immediate addressing mode
Accumulator addressing mode
Direct addressing mode
Direct bit addressing mode
Direct indexed X addressing mode
Direct indexed Y addressing mode
Direct indirect addressing mode
Direct indexed X indirect addressing mode
Direct indirect indexed Y addressing mode
Direct indirect long addressing mode
Direct indirect long indexed Y addressing mode
Absolute addressing mode
Absolute bit addressing mode
Absolute indexed X addressing mode
Absolute indexed Y addressing mode
Absolute long addressing mode
Absolute long indexed X addressing mode
Absolute indirect addressing mode
Absolute indirect long addressing mode
Absolute indexed X indirect addressing mode
Stack addressing mode
Relative addressing mode
Direct bit relative addressing mode
Absolute bit relative addressing mode
Stack pointer relative addressing mode
–
←
A
CC
A
CCH
A
CCL
A
A
H
A
L
B
B
H
B
L
X
X
H
X
L
Y
Y
H
Y
L
S
PC
PC
H
PC
L
PG
DT
DPR
DPR
H
DPR
L
PS
PS
H
PS
L
PS
b
M(S)
Mb
AD
G
AD
H
AD
L
op
n
#
i
i
1
, i
2
Exclusive OR
Negation
Movement to the arrow direction
Accumulator
Accumulator’s upper 8 bits
Accumulator’s lower 8 bits
Accumulator A
Accumulator A’s upper 8 bits
Accumulator A’s lower 8 bits
Accumulator B
Accumulator B’s upper 8 bits
Accumulator B’s lower 8 bits
Index register X
Index register X’s upper 8 bits
Index register X’s lower 8 bits
Index register Y
Index register Y’s upper 8 bits
Index register Y’s lower 8 bits
Stack pointer
Program counter
Program counter’s upper 8 bits
Program counter’s lower 8 bits
Program bank register
Data bank register
Direct page register
Direct page register’s upper 8 bits
Direct page register’s lower 8 bits
Processor status register
Processor status register’s upper 8 bits
Processor status register’s lower 8 bits
Processor status register’s b-th bit
Contents of memory at address indicated by
stack pointer
b-th memory location
Value of 24-bit address’s upper 8-bit (A
23
–A
16
)
Value of 24-bit address’s middle 8-bit (A
15
–A
8
)
Value of 24-bit address’s lower 8-bit (A
7
–A
0
)
Operation code
Number of cycle
Number of byte
Number of transfer byte or rotation
Number of registers pushed or pulled
∨