|
| |
Decrement by 1
|
86/88 |
Y |
186 |
Y |
286 |
Y |
386 |
Y |
486 |
Y |
DEC destination |
|
Ovfl |
Y |
Dir |
N |
Int |
N |
Trap |
N |
Sign |
Y |
Zero |
Y |
Aux |
Y |
Prty |
Y |
Carry |
Y |
This instruction decrements the destination by one. The destination
operand, which may be either a word or a byte, is treated as an
unsigned binary number.
Note: This instruction does not set the carry, so if you
need to decrement a multi-word number, it is better
to use the SUB and SBB instructions.
------------------------------------ Timing ----------------------------------
OpCode Instruction 386 286 86
FE/1 DEC r/m8 2/6 2/7 3/15+EA
FE/1 DEC r/m16 2/6 2/7 3/15+EA
48+rw DEC r16 2 2 3
48+rw DEC r32 2
------------------------------------ Logic -----------------------------------
destination = destination - 1
See Also INC SUB SBB AAS DAS Flags |