Question

在内部RAM20H和21H单元中存放着一个16位的补码数,期中H单元存放高8位.试编写程序求出其原码,

Answer 1

;

JNB 21H.7,TUICHU

CLR A

CLR C

SUBB A,20H

MOV 20H,A

SUBB A,21H

MOV 21H,A

SETB 21H.7

TUICHU:

SJMP $

END