矩阵式键盘的识别（一）.asm

基于Proteus的51系列单片机设计与仿真

        ORG  0000H
        AJMP MAIN
        ORG  0100H        
  MAIN: MOV P2,#000H              
  KEY0: MOV P3,#0FEH   ;[11111110]FE,置P3.0低电平扫描P3.4~P3.7键值
        JNB P3.4,K0
        JNB P3.5,K1
        JNB P3.6,K2
        JNB P3.7,K3
        MOV P3,#0FDH  ;[11111101]FD,置P3.1低电平扫描P3.4~P3.7键值
        JNB P3.4,K4
        JNB P3.5,K5
        JNB P3.6,K6
        JNB P3.7,K7     
        MOV P3,#0FBH ;[11111011]FB,置P3.2低电平扫描P3.4~P3.7键值
        JNB P3.4,K8
        JNB P3.5,K9
        JNB P3.6,K10
        JNB P3.7,K11   
        MOV P3,#0F7H ;[11110111]FE,置P3.3低电平扫描P3.4~P3.7键值
        JNB P3.4,K12
        JNB P3.5,K13
        JNB P3.6,K14
        JNB P3.7,K15    
        AJMP KEY0
        
 ;键码显示子程序
 ;----------------------------------------       
  K0:   MOV P2,#03FH ;0
        ACALL YSH1S
        AJMP KEY0
        RET
  K1:   MOV P2,#006H ;1
        ACALL YSH1S
        AJMP KEY0
        RET              
  K2:   MOV P2,#05BH ;2
        ACALL YSH1S
        AJMP KEY0
        RET
  K3:   MOV P2,#04FH ;3
        ACALL YSH1S
        AJMP KEY0
        RET
  ;----------------------------
  K4:   MOV P2,#066H ;4
        ACALL YSH1S
        AJMP KEY0
        RET
        
  K5:   MOV P2,#06DH ;5
        ACALL YSH1S
        AJMP KEY0
        RET              
  K6:   MOV P2,#07DH ;6
        ACALL YSH1S
        AJMP KEY0
        RET
  K7:   MOV P2,#007H ;7
        ACALL YSH1S
        AJMP KEY0
        RET
 ;--------------------
  K8:   MOV P2,#07FH ;8
        ACALL YSH1S
        AJMP KEY0
        RET
  K9:   MOV P2,#06FH ;9
        ACALL YSH1S
        AJMP KEY0
        RET              
  K10:  MOV P2,#077H ;A
        ACALL YSH1S
        AJMP KEY0
        RET
  K11:  MOV P2,#07CH ;b
        ACALL YSH1S
        AJMP KEY0
        RET
  ;------------------------
  K12:  MOV P2,#039H ;C
        ACALL YSH1S
        AJMP KEY0
        RET
  K13:  MOV P2,#05EH ;d
        ACALL YSH1S
        AJMP KEY0
        RET              
  K14:  MOV P2,#079H ;E
        ACALL YSH1S
        AJMP KEY0
        RET
  K15:  MOV P2,#071H ;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