矩阵式键盘的识别（二）.asm

基于Proteus的51系列单片机设计与仿真

        ORG  0000H
        AJMP main
        ORG  0100H              
  main: MOV P3,#0FH
  KEY0: MOV P0,#0FEH   ;[11111110]FE,置P0.0低电平扫描P0.4~P0.7键值
        JNB P0.4,K0
        JNB P0.5,K1
        JNB P0.6,K2
        JNB P0.7,K3
        MOV P0,#0FDH  ;[11111101]FD,置P0.1低电平扫描P0.4~P0.7键值
        JNB P0.4,K4
        JNB P0.5,K5
        JNB P0.6,K6
        JNB P0.7,K7     
        MOV P0,#0FBH ;[11111011]FB,置P0.2低电平扫描P0.4~P0.7键值
        JNB P0.4,K8
        JNB P0.5,K9
        JNB P0.6,K10
        JNB P0.7,K11   
        MOV P0,#0F7H ;[11110111]FE,置P0.3低电平扫描P0.4~P0.7键值
        JNB P0.4,K12
        JNB P0.5,K13
        JNB P0.6,K14
        JNB P0.7,K15    
        AJMP KEY0        
 ;键码显示子程序
  K0:   MOV P3,#1EH ;0
        ACALL YSH1S
        AJMP KEY0
        RET
  K1:   MOV P3,#2EH ;1
        ACALL YSH1S
        AJMP KEY0
        RET              
  K2:   MOV P3,#4EH ;2
        ACALL YSH1S
        AJMP KEY0
        RET
  K3:   MOV P3,#8EH ;3
        ACALL YSH1S
        AJMP KEY0
        RET
  K4:   MOV P3,#1DH ;4
        ACALL YSH1S
        AJMP KEY0
        RET       
  K5:   MOV P3,#2DH ;5
        ACALL YSH1S
        AJMP KEY0
        RET              
  K6:   MOV P3,#4DH ;6
        ACALL YSH1S
        AJMP KEY0
        RET
  K7:   MOV P3,#8DH ;7
        ACALL YSH1S
        AJMP KEY0
        RET
  K8:   MOV P3,#1BH ;8
        ACALL YSH1S
        AJMP KEY0
        RET
  K9:   MOV P3,#2BH ;9
        ACALL YSH1S
        AJMP KEY0
        RET              
  K10:  MOV P3,#4BH ;A
        ACALL YSH1S
        AJMP KEY0
        RET
  K11:  MOV P3,#8BH ;b
        ACALL YSH1S
        AJMP KEY0
        RET
  K12:  MOV P3,#17H ;C
        ACALL YSH1S
        AJMP KEY0
        RET
  K13:  MOV P3,#27H ;d
        ACALL YSH1S
        AJMP KEY0
        RET              
  K14:  MOV P3,#47H ;E
        ACALL YSH1S
        AJMP KEY0
        RET
  K15:  MOV P3,#87H ;F
        ACALL YSH1S
        AJMP KEY0
        RET   
  ;延时子程序      
  YSH1S: MOV R3,#05H
  LOOP:  MOV R4,#0A8H
  LOOP1: MOV R5,#08AH
  XHD:  DJNZ R5,XHD
        DJNZ R4,LOOP1
        DJNZ R3,LOOP
        RET   
        END