单片机60S倒计时汇编语言

ORG  0000H  
   AJMP MAIN
   ORG  000BH
   AJMP INTT0
   ORG  0030H
MAIN: MOV R7,#60
      MOV R6,#00H
   MOV DPTR,#TABLE
   MOV TMOD,#01H       
          MOV TL0,#0B0H
   MOV TH0,#3CH  ;设置定时器工作方式、初值
   SETB EA
   SETB ET0 
   SETB TR0
NEXT: MOV A,R7
      MOV B,#0AH
   DIV AB
   SETB  P1.3
   MOVC A,@A+DPTR
   MOV P0,A
   CLR   P1.4     ;开启shi位显示
   ACALL DELAY
   MOV A,B
   SETB  P1.4
   MOVC A,@A+DPTR
       
   MOV P0,A
   CLR   P1.3       ;开启ge位显示
   ACALL DELAY
   CJNE R6,#14H,NEXT
   MOV R6,#00H
   DEC R7
   CJNE  R7,#0FFH,NEXT
   SJMP MAIN
INTT0:MOV TL0,#0B0H  ;中断服务程序
   MOV TH0,#3CH
   INC R6
   RETI
DELAY:MOV R5,#02H  ;延时子程序
 LOOP:MOV R4,#02H
   DJNZ R4,$
   DJNZ R5,LOOP
   RET
TABLE:DB 0C0H,0F9H,0A4H,0B0H,99H,92H,82H,0F8H,80H,90H
   END

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