频率计初步.asm

是我在电子竞赛期间写的一些单片机汇编程序

org 0000h
ajmp main
org 0003h
ajmp intx0
org 000bh
ajmp intt0
org 0100h
main:
      mov     sp,#5fh
      setb    it0
      setb    px0        ;外部中断0优先
      mov     tmod,#02h
xiayi:mov     th0,#38h
      mov     tl0,#38h
      SETB    EA
      SETB    ET0
      SETB    EX0   ;   外中断
      setb    tr0
      mov     r7,#72
      mov r6,#00h
wait: acall   display
      cjne    r7,#00h,wait
      mov     ie,#00h   ;只显示一秒到时的所测频率
      clr     tr0
      mov     r1,#30h;   (30h)送到40单元
      mov     r0,#40h
zaici:mov     b,@r1
      mov     @r0,b
      inc     r0
      inc     r1
      cjne    r1,#38h,zaici
      mov     r0,#30h
fanh: mov     @r0,#00h  ;将显示寄存器地址内容清零
      inc     r0
      cjne    r0,#38h,fanh
      ajmp    xiayi


display:
        MOV R0,#40H
        MOV 50H,#0BFH
DIS2:
        MOV A,@R0
        ACALL TABLE
        MOV P2,A
        MOV P0,50H
        ACALL DELAY
        MOV P0,#0FFH
        INC R0
        MOV A,50H
        RR A
        MOV 50H,A
        CJNE R0,#44H,DIS2
        RET


intx0:      ;外中段
      push        psw
      push        acc
      clr         ex0  ;禁止外中断
      mov         r1,#30h
cmp:  cjne        @r1,#09h,first
      mov         @r1,#00h
      inc         r1
      cjne        r1,#38h,cmp
      ajmp        wanbi
first:inc         @r1
wanbi:setb        ex0
      pop         acc
      pop         psw
      reti


intt0:               ;定时器0中断
      push     psw
      push     acc
      inc r6
      cjne r6,#64,huiqu
      mov r6,#00h
      dec      r7
huiqu:
      pop      acc
      pop      psw
      reti


delay:
       mov       r5,#10h
delay0:mov       r4,#40h
delay1:djnz      r4,delay1
       djnz      r5,delay0
       ret


table:
      inc       a
      movc      a,@a+pc
      ret
      db        0c0h,0f9h,0a4h,0b0h,099h,092h,082h,0f8h,80h,090h
      end