60dao.asm

可实现0到99秒的计时。程序简单易读

            ORG 0000H
            LJMP MAIN
            ORG 000BH
            SJMP T0Z
            ORG 0030H
       MAIN:MOV TMOD,#01H
            MOV TH0,#9EH
            MOV TL0,#58H
            MOV DPTR,#TAB
            MOV R0,#00H
            MOV R1,#00H
            SETB ET0
            SETB EA
            SETB TR0
       DISP:MOV A,R0
            MOV B,#10
            DIV AB
            MOVC A,@A+DPTR
            MOV P2,A
            SETB P3.0
            LCALL DELAY
            CLR P3.0
            MOV A,B
            MOVC A,@A+DPTR
            MOV P2,A
            SETB P3.1
            LCALL DELAY
            CLR P3.1
            SJMP DISP
        T0Z:MOV TH0,#9EH
            MOV TL0,#58H
            INC R1
            CJNE R1,#40,LP
            INC R0
            MOV R1,#00
            CJNE R0,#60,LP
            MOV R0,#00
         LP:RETI
        TAB:DB 0C0H,0F9H,0A4H,0B0H
            DB 99H,92H,82H,0F8H
            DB 80H,90H,88H,83H
            DB 0C6H,0A1H,86H,8EH
      DELAY:MOV R7,#20
         D1:MOV R6,#200
            DJNZ R6,$
            DJNZ R7,D1
            RET
            END