51定时器实现频率检测-EDA365

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51定时器实现频率检测

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标签:
频率检测
51定时器

用51的定时器实现频率计算

   $mod52
   org 0h
   ljmp start
   org 0bh
   ljmp t0int
   org 1bh
   ljmp t1int
   org 100h
start:
   mov sp,#50h
   mov ie,#8ah
   mov ip,#0ah
   mov tmod,#11h
   mov 20h,#14h
   mov 21h,#00h
   mov tl0,#0bah
mov th0,#03ch
setb tr0
   setb tr1
loop:
   lcall 8300h
   sjmp loop
t0int:
mov tl0,#0bah
   mov th0,#03ch
   djnz 20h,nex
   push acc
read:

   mov 22h,21h
   mov a,th1
   mov 24h,tl1
   cjne a,th1,read
mov 23h,a
   pop acc
mov th1,#00
   mov tl1,#00
   mov 21h,#00
   mov 20h,#14h
nex:
   reti
t1int:
   inc 21h
   reti
end