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CPU6502 Instruction Manual v2.1
Sunplus reserves the rights to change this documentation without prior notice.
09/13/2005
32
DEC
Decrement memory by one
Available Instruction
& No. Cycles
Addressing
mode
Assembly
Language
Form
6502
Opcode
Sunplus
Opcode
No.
Bytes
65b02 65n02 65r02 65s02
CPU12
Zero Page DEC aa
C6H
A3H
2
5
5
5
5
5
Zero Page, X DEC aa, X
D6H
ABH
2
6
6
6
X
6
Absolute
DEC
aaaa CEH E3H 3 6 6 X X X
Absolute, X DEC aaaa, X
DEH
EBH
3
6 7 X X X
X: Not available.
N V D I Z C
! - - - ! -
N: Set if result is negative
Z: Set if result is 0
DEX
Decrement Register X by one
Available Instruction
& No. Cycles
Addressing
mode
Assembly
Language
Form
6502
Opcode
Sunplus
Opcode
No.
Bytes
65b02 65n02 65r02 65s02
CPU12
Implied
DEX CAH E2H 1 2 2 2 2 2
N V D I Z C
! - - - ! -
N: Set if result is negative
Z: Set if result is 0