问题
填空题
已知(R0)=20H,(20H)=36H,(21H)=17H,(36H)=34H,执行下列程序后,则(R0)=______(R2)=______。
MOV A,@R0
MOV R0,A
MOV A,@R0
ADD A,21H
ORL A,#21H
RL A
MOV R2 A
RET
答案
参考答案:36H F6H
解析:
MOV A,@R0
MOV R0,A ;R0=36H
MOV A,@R0 ;A=34H
ADD A,21H :A=34H+17H=5BH
ORL A,#21H ;01011011∨00100001=01111011
RL A ;A=11110110=F6H
MOV R2 A ;R2=F6H
RET