下位机软件.asm

来自「简易数字频率计」· 汇编 代码 · 共 71 行

     org 0000H
     ljmp main

     org 0023h
     ljmp dori
     org 0040h
main:mov sp,#5fh
     mov  tmod  ,#29h
     mov  tl0,#00h
     mov  th0,#00h
     mov th1,#0f3H
     mov tl1,#0F3H
     mov pcon,#00h
     mov scon,#50H  ; 串行口设置  外接晶振12MHZ,波特率2400
     setb  tr1
lp:acall mar
   acall delay
   sjmp  lp

send: clr ea
      clr es
      mov sbuf ,a
      jnb ti ,$
      clr ti
      setb es
      setb ea
      setb f0
      ret

dori:push dph
     push dpl
     push acc
     clr ea
     mov r1, #40h
     mov r6,#3
lpri:jnb ri , $
     mov a,sbuf
     mov  @r1 ,a
     clr ri
     inc r1
     djnz  r6,lpri
     setb ea
     pop acc
     pop dpl
     pop dph
     clr f1
     reti



mar:mov  tl0,#00h
    mov  th0,#00h
    setb  p3.2
    jb   p3.2 ,$
    setb  tr0
    jnb  p3.2 ,$
    jb   p3.2 ,$
    clr  tr0
    mov  a ,th0
    acall send
    mov  a, tl0
    acall send
    ret
delay:mov 32h,#10
    d1: mov 33h,#50
    d2: mov 34h,#250
        djnz 34h,$
        djnz 33h,d2
        djnz 32h,d1
        ret