秒表程序.asm

秒表程序

        ORG   0000H
        AJMP  START
        ORG   0003H
        AJMP  SERI0
        ORG   000BH
        AJMP  SERT0
        ORG   001BH
        AJMP  SERT1
        ORG   0100H
       ;主程序

START:  MOV    SP,#5FH
        SETB   PT0
        CLR    PT1
        MOV    TMOD,#11H
        MOV    TL0,#78H
        MOV    TH0,#0ECH
        MOV    TL1,#0CH
        MOV    TH1,#0FEH
        MOV    40H,#00H
        MOV    30H,#00H
        MOV    31H,#00H
        MOV    32H,#00H
        MOV    R0,#36H
        MOV    R2,#01H

        SETB   EA
        SETB   EX0
        SETB   ET0
        SETB   ET1
        SETB   IT0
        SETB   TR1
        CLR    TR0
        SJMP   $

  ;INT0 中断服务程序
SERI0:   PUSH  ACC
        MOV    A,40H
        CJNE   A,#01H,NOEQR
 ONE:   CLR    TR0
        MOV    40H,#02H
        AJMP   BACK
 NOEQR: JC     ZERO
  TWO:  CLR    TR0
        MOV     30H,#00H
        MOV     31H,#00H
        MOV     32H,#00H
        MOV     40H,#00H
        AJMP   BACK
 ZERO : SETB   TR0
        MOV    40H,#01H
  BACK:  POP   ACC
        RETI

    ;T1中断服务程序
SERT1:   PUSH  ACC
        MOV   TL1,#0CH
        MOV   TH1,#0FEH
        SETB   TR1
        MOV   DPTR,#TABLE
        MOV   A , @R0
        MOVC  A , @A+DPTR
        CLR   C
        MOV   R3,#08H
LOOP:   RLC   A
        MOV   ACC.0 ,C
        MOV   DPTR,#0FE06H
        MOVX  @DPTR,A
        SETB  ACC.0
        MOV   DPTR,#0FE04H
        MOVX  @DPTR,A
        CLR   ACC.0
        MOVX  @DPTR,A
        DJNZ  R3,LOOP
        MOV   DPTR,#0FE02H
        MOV   A,R2
        MOVX  @DPTR,A
        CJNE  R0,#3CH,NOE
        MOV   R0,#36H
        MOV   R2,#01H
        SJMP  BACK1
 NOE:   INC   R0
        MOV   A,R2
        RL    A
        MOV   R2,A
        
 BACK1: POP   ACC
        RETI
 ;  T0中断服务程序
 SERT0:  PUSH ACC
        MOV   TL0,#078H
        MOV   TH0,#0ECH
        MOV   A,30H
        ADD   A,#01H
        DA    A
        MOV   30H,A
        CJNE A, #00H,X0
        MOV   A,31H
        ADD   A,#01H
        DA    A
        MOV   31H,A
        CJNE  A,#60H,X0
        MOV   31H,#00H
        MOV   A,32H
        ADD   A,#01H
        DA    A
        MOV   32H,A
        CJNE  A,#60H,X0
        MOV   32H,#00H
X0:     LCALL DISP
         POP  ACC
        RETI
  ;写缓冲区
DISP:   PUSH  ACC
        MOV   R1,#36H
        MOV    A,30H
        MOV   B,#10H
        DIV   AB
        MOV   @R1,B
        INC   R1
        MOV   @R1,A
        INC   R1

        MOV   A,31H
        MOV   B,#10H
        DIV   AB
        MOV   @R1,B
        INC   R1
        MOV   @R1,A
        INC   R1


       MOV    A,32H
       MOV    B,#10H
       DIV    AB
       MOV    @R1,B
       INC    R1
       MOV    @R1,A
       POP    ACC      
       RET
TABLE: DB     03FH,06H,5BH,4FH,66H,6DH,7DH,07H,7FH,6FH
       END