7.asm

吉林大学计算机学院控制实验的几个必做实验的源代码(大四)~

ORG 0000H
LJMP START
ORG 0003H
LJMP INTO
START:CLR EA
      MOV TMOD,#09H
      MOV TH0,#00H
      MOV TL0,#00H
      SETB TR0
      SETB EA
      SETB EX0
      SETB IT0
L:CLR EX0
  LCALL SHOW
  SETB EX0
  SJMP L
INTO:MOV A,TH0
     CLR CY
     RRC A
     MOV R1,A
     MOV A,TL0
     RRC A
     MOV R2,A
     CLR CY
     MOV A,R1
     RRC A
     MOV R1,A
     MOV A,R2
     RRC A
     MOV R2,A
     MOV A,R2
     CLR CY
     SUBB A,#33H    
COM:MOV R2,A
    MOV A,R1
    SUBB A,#27H
    MOV R1,A
    MOV TH0,#00H
    MOV TL0,#00H
    RETI
SHOW:MOV A,R2
     MOV B,#16
     DIV AB
     MOV R3,A
     MOV R4,B
     MOV DPTR,#0FF21H
     MOV A,#01H
     MOVX @DPTR,A
     MOV A,R4
     MOV DPTR,#DIG
     MOVC A,@A+DPTR
     MOV DPTR,#0FF22H
     MOVX @DPTR,A
     MOV A,#0FFH
WAIT1:DEC A
      JNZ WAIT1
      MOV DPTR,#0FF21H
      MOV A,#02H
      MOVX @DPTR,A
      MOV A,R3
      MOV DPTR,#DIG
      MOVC A,@A+DPTR
      MOV DPTR,#0FF22H
      MOVX @DPTR,A
      MOV A,#0FFH
WAIT2:DEC A
      JNZ WAIT2
      MOV A,R1
      MOV B,#16
      DIV AB
      MOV R3,A
      MOV R4,B
      MOV DPTR,#0FF21H
      MOV A,#04H
      MOVX @DPTR,A
      MOV A,R4
      MOV DPTR,#DIG
      MOVC A,@A+DPTR
      MOV DPTR,#0FF22H
      MOVX @DPTR,A
      MOV A,#0FFH
WAIT3:DEC A
      JNZ WAIT3
      MOV DPTR,#0FF21H
      MOV A,#08H
      MOVX @DPTR,A
      MOV A,R3
      MOV DPTR,#DIG
      MOVC A,@A+DPTR
      MOV DPTR,#0FF22H
      MOVX @DPTR,A
      MOV A,#0FFH
WAIT4:DEC A
      JNZ WAIT4
      RET
DIG:DB 0C0H,0F9H,0A4H,0B0H
    DB 99H,92H,82H,0F8H
    DB 80H,98H,88H,83H
    DB 0C6H,0A1H,86H,8EH
END