scankey.asm

一个简单的单片机电子钟程序

SET8255: MOV DPTR,#8003H
         MOV A,#81H
         MOVX @DPTR,A
         MOV R1,#6AH
  START1:LCALL SCAN
         LCALL KEYPLAY
         SJMP START1
SCAN:
   DIR1: MOV R0,#6AH
         MOV R3,#01H
         MOV A,R3
    DI1: MOV DPTR,#8000H
         MOVX  @DPTR,A
         MOV  A,@R0
         MOV  DPTR,#CODE1
         MOVC A,@A+DPTR
         MOV  DPTR,#8001H
         MOVX @DPTR,A


         ACALL DELAY1
         INC R0
         MOV A,R3
         JB ACC.5,DI11
         RL A
         MOV R3,A
         AJMP DI1

    DI11:JMP  SCANOUT


    CODE1:DB 3FH,06H,5BH,4FH,66H,6DH
          DB 7DH,07H,7FH,6FH,77H,7CH
          DB 39H,5EH,79H,71H,73H,3EH
          DB 31H,6EH,1CH,23H,40H,03H
          DB 18H,00H,00H,00H
  DELAY1:MOV R7,#02H
  DE1:   MOV R6,#0FFH
  DE2:   DJNZ R6,DE2
         DJNZ R7,DE1
SCANOUT:RET
KEYPLAY:
KKEYBORAD:
KEY1:   ACALL KS1
        JNZ LK1
KEY2:   ACALL TM6ms
        RET
LK1:    ACALL TM12ms
        ACALL KS1
        JNZ LK2
        AJMP KEY2
LK2:    MOV R2,#0DFH     ;ZU HANG SAOMIAO
        MOV R5,#4
        MOV R4,#00H
LK4:    MOV DPTR,#8000H
        MOV A,R2
        MOVX @DPTR,A
        INC DPTR
        INC DPTR
        MOVX A,@DPTR
        JB ACC.0,LONE    ;cha di yi hang
        MOV A,#00H        ;  #00-a
        AJMP LKP          ;
LONE:   JB ACC.1,LTWO
        MOV A,#04H
        AJMP LKP
LTWO:   JB ACC.2,LTHR
        MOV A,#08H
        AJMP LKP
LTHR:   JB ACC.3,NEXT
        MOV A,#0CH
LKP:    ADD A,R4          ;qiu jian ma

        ACALL KEYIN

        PUSH ACC
LK3:    ACALL KS1         ;deng jian shi fang
        JNZ LK3
        POP ACC
        RET
NEXT:   INC R4
        MOV A,R2
        RR A
        MOV R2,A
        DJNZ R5,LK4
KEND:   RET

KEYIN:
        MOV   DPTR,#KEYTAB
        MOVC  A,@A+DPTR
        MOV   @R1,A
        INC  R1
        RET


KS1:    MOV DPTR,#8000H   ;判断有无键按下
        MOV A,#00H
        MOVX @DPTR ,A
        INC DPTR
        INC DPTR
        MOVX A,@DPTR
        CPL A
        ANL A,#0FH      ;A=/0有间暗下
        RET



TM12ms: MOV R7,#18
TM:     MOV R6,#0FFH
TM6:   DJNZ R6,TM6
        DJNZ R7,TM
        RET
TM6ms:  MOV R7,#0CH
TM2:    MOV R6,#0FFH
TM62:   DJNZ R6,TM62
        DJNZ R7,TM
        RET



KEYTAB: DB 00H,0FH,0EH,0DH
        DB 01H,02H,03H,0CH
        DB 04H,05H,06H,0BH
        DB 07H,08H,09H,0AH