假设P3.0接K1信号,P3.1接K2信号,P3.2接K3信号
ORG 4000H
LJMP START
START:MOV A,P3
ANL A,#07H //屏蔽P3口高5位,只有P3.0-P3.2
JZ L1 // A=0,说明P3.0-P3.2全为0
CJNE A,#07H,L2 //A=7,说明P3.0-P3.2全为1
L1: MOV P1,#00H
SJMP L3
L2: CJNE A,#03H,L4 //P3.0、P3.1=1
MOV P1,#04H
SJMP L3
L4: CJNE A,#06H,L5 //P3.1、P3.2=1
MOV P1,#01H
SJMP L3
L5: CJNE A,#05H,L6 //P3.0、P3.2=1
MOV P1,#02H
SJMP L3
L6: MOV P1,A
L3: RET |