User's Manual

MSM80C154S/83C154S/85C154HVS
282
32. DEC Rr (Decrement register)
00011r2 r1 r0
70
Instruction code
Operation
Number of bytes
Number of cycles
Flags
(PSW)
Description
Example DEC R7
Instruction code
: Byte 1
(Rr)←(Rr)–1 r=0 thru 7:
C AC F0 RS1 RS0 OV F1 P
:
:
:
The register r contents are decremented by 1.:
00011111
70
Byte 1
Register 7
10000000
70
1
1
Before execution
Register 7
01111111
70
After execution
: