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