user manual

8XC251SA, SB, SP, SQ USER’S MANUAL
A-54
DEC Rn
Binary Mode Source Mode
Bytes: 12
States: 12
Hex Code in: Binary Mode = [Encoding]
Source Mode = [A5][Encoding]
Operation: DEC
(Rn) ← (Rn) – 1
DEC <dest>,<src>
Function: Decrement
Description: Decrements the specified variable at the destination operand by 1, 2, or 4. An original value
of 00H underflows to 0FFH.
Flags:
Example: Register 0 contains 7FH (01111111B). After executing the instruction sequence
DEC R0,#1
register 0 contains 7EH.
Variations
DEC Rm,#short
Binary Mode Source Mode
Bytes: 32
States: 21
Hex Code in: Binary Mode = [A5][Encoding]
Source Mode = [Encoding]
Operation: DEC
(Rm) ← (Rm) – #short
DEC WRj,#short
Binary Mode Source Mode
Bytes: 32
States: 21
[Encoding] 0 0 0 1 1 r r r
CY AC OV N Z
———✓✓
[Encoding] 0 0 0 1 1 0 1 1 s s s s 0 1 v v