数模转换

ORG 0000H
AJMP  KEYIN
ORG 0003H
AJMP INSER
ORG  001BH
AJMP  SERVE
KEYIN:SETB EX0
      SETB IT0
      SETB EA
CHECK:MOV A,#90H
      MOV DPTR,#0FF7FH
      MOVX @DPTR,A
      MOV A,#00H
      MOV  DPTR,#0FF7EH
      MOVX @DPTR,A
      MOV  A,#01H
      MOV DPTR,#0FF7DH
ODIS: MOVX  @DPTR,A
     ACALL  ODIMS
     RL A
     AJMP   ODIS
ODIMS:MOV R7,#05H
ODL:  MOV R6,#0C8H
ODL1: MOV R5,#0FFH
DL2: DJNZ R5,DL2
     DJNZ R6,ODL1
     DJNZ R7,ODL
     RET
INSER:LCALL D10MS
      MOV DPTR,#0FF7CH
      MOV  A,#0FFH
      MOVX @DPTR,A
      MOVX A,@DPTR
      ANL A,#01H
      CJNE A,#00H,CHECK
MAIN: MOV  A,#90H
      MOV  DPTR,#0FF7FH
       MOVX  @DPTR,A
     MOV TMOD,#10H
     MOV 36H,#14H
     CLR A
     MOV 30H,A
     MOV 31H,A
     MOV 32H,A
     MOV 33H,A
     MOV 34H,A
     MOV 35H,A
     SETB ET1
     SETB EA
     MOV  TH1,#3CH
     MOV  TL1,#0B0H
     SETB TR1
     SJMP  DIS
SERVE:PUSH  PSW
     PUSH  ACC
     MOV TH1,#3CH
     MOV TL1,#0B0H
     DJNZ 36H,RETUNT
     MOV 36H,#14H
     MOV A,#01H
     ADD  A,35H
      MOV  R1,A
     DA   A
     MOV  35H,A
      MOV A,R1
     CJNE   A,#10,RETUNT
     MOV 35H,#00H
     MOV A,#01H
     ADD  A,34H
     DA   A
     MOV  34H,A
     CJNE  A,#6,RETUNT
     MOV  34H,#00H
     MOV A,#01H
     ADD  A,33H
     MOV R3,A
     DA  A
     MOV 33H,A
      MOV  A,R3
     CJNE  A,#10,RETUNT
     MOV  33H,#00H
     MOV  A,#01H
     ADD  A, 32H
     DA  A
     MOV 32H,A
     CJNE  A,#6,RETUNT
     MOV  32H,#00H
     MOV  A,#01H
     ADD  A,31H
      DA A
     MOV 31H,A
     MOV  A,30H
     CJNE   A,#2,SPARE
     MOV A,31H
     CJNE  A,#4,RETUNT
     MOV 31H,#00H
     MOV  31H,#00H
     AJMP  RETUNT
SPARE:MOV  A,31H
     CJNE A,#10,RETUNT
     MOV 31H,#00H
     MOV A,#01H
     ADD  A,30H
     DA  A
     MOV  30H,A
RETUNT:POP  ACC
      POP  PSW
     RETI
DIS:MOV  R0,#35H
    MOV  R2,#20H
    MOV  A,R2
LP0:MOV DPTR,#0FF7DH
    MOVX @DPTR,A
    MOV DPTR,#0FF7EH
    MOV A,@R0
    ADD  A,#0DH
    MOVC  A,@A+PC
    MOVX @DPTR,A
    ACALL  DIMS
    MOV  A,R2
    JB  ACC.0,DIS
    RR  A
    MOV   R2,A
    DEC  R0
    AJMP  LP0
LP1: RET
TABL: DB  0C0H,0F9H,0A4H,0B0H,99H,92H,82H,0F8H,80H,90H
DIMS:MOV R7,#02H
DL:  MOV R6,#0FFH
DL1: DJNZ  R6,DL1
     DJNZ R7,DL
     RETI
D10MS:MOV R7,#14H
      NDL:MOV R6,#0FFH
      NDL1:DJNZ R6,NDL1
      DJNZ R7,NDL
      RET
     END