例3.12
假设(DS)=1000H, (SS)=4000H, (SP)=100H, (BX)=2100H, (12100)=00A8H,
指出连续执行下列各条指令后,有关寄存器、存储单元以及堆栈的情况。
PUSH DS
PUSH BX
PUSH [BX]
POP DI
POP WORD PTR [DI+2]
POP DS

执行结果: (SP)=100H-2=0FEH (SP)=0FE-2=0FCH
(SP)=0FC-2=0FAH
(400FEH)=1000H (400FCH)=2100H (400FAH)=00A8H

执行结果: (SP)=0FA+2=0FCH (SP)=0FC+2=0FEH (SP)=0FE+2=100H
(DI)=00A8H (100AAH)=2100H (DS)=1000H
例3.13
已知(AX)=6634H, (BX)=0F24H, (SI)=0012H, (DS)=1200H, (12F36H)=2500H,
写出下列指令执行的结果。
XCHG AH,AL ; 执行前: (AH)=66H, (AL)=34H
; 执行后: (AH)=34H, (AL)=66H
XCHG AX,[BX+SI] ; 执行前: (AX)=6634H, (12F36H)=2500H
; 执行后: (AX)=2500H, (12F36H)=6634HH