|
| |
Exchange Registers
|
86/88 |
Y |
186 |
Y |
286 |
Y |
386 |
Y |
486 |
Y |
XCHG destination, source |
|
Ovfl |
N |
Dir |
N |
Int |
N |
Trap |
N |
Sign |
N |
Zero |
N |
Aux |
N |
Prty |
N |
Carry |
N |
XCHG switches the contents of its operands, which may be either bytes
or words.
Note: Used in conjunction with the LOCK prefix, this
instruction is particularly useful when implementing
semaphores to control shared resources.
------------------------------------ Timing ----------------------------------
OpCode Instruction 386 286 86
86/r XCHG r/m8, r8 3/5 3/5 4/17+EA
86/r XCHG r8, r/m8 3/5 3/5 4/17+EA
87/r XCHG r/m16, r16 3/5 3/5 4/17+EA
87/r XCHG r16, r/m16 3/5 3/5 4/17+EA
87/r XCHG r/m32, r32 3/5
87/r XCHG r32, r/m32 3/5
91+r XCHG AX, r16 3 3 3
91+r XCHG r16, AX 3 3 3
91+r XCHG EAX, r32 3
91+r XCHG r32, EAX 3
------------------------------------ Logic -----------------------------------
destination <--> source
See Also MOV PUSH POP XLAT LOCK |