Question

汇编语言中已知两个16位字数据4321H和0DCBAH,它们相加后的结果是多少?标志位CF,ZF,SF的值各是多少

Answer 1

C:DOCUME~1ADMINI~1>DEBUG

-A

17B7:0100 MOV AX,4321

17B7:0103 ADD AX,DCBA

17B7:0106 NOP

17B7:0107

-R

AX=0000 BX=0000 CX=0000 DX=0000 SP=FFEE BP=0000 SI=0000 DI=0000

DS=17B7 ES=17B7 SS=17B7 CS=17B7 IP=0100 NV UP EI PL NZ NA PO NC

17B7:0100 B82143 MOV AX,4321

-G106

AX=1FDB BX=0000 CX=0000 DX=0000 SP=FFEE BP=0000 SI=0000 DI=0000

DS=17B7 ES=17B7 SS=17B7 CS=17B7 IP=0106 NV UP EI PL NZ NA PE CY

17B7:0106 90 NOP

-

显然,标志位CF,ZF,SF的值分别是1,0,0.