shijian.asm

51单片机精确定时,11.0592mhz晶体可基本无误差

SEC BIT 20H
COUNT DATA 64H
COUNT1 DATA 65H

org 0000h
ajmp  start

org 000bh
ajmp   chuli

start:

mov TMOD,#00h
mov TH0,#70h
mov	 TL0,#00H
setb TR0
MOV COUNT,#200
MOV COUNT1,#10
SETB EA
SETB ET0

loop:
nop
sjmp loop

ret

chuli:
PUSH PSW
PUSH ACC

DJNZ COUNT ,LOOP1
MOV COUNT,#200
DJNZ COUNT1,LOOP1
MOV COUNT1,#10
SETB SEC
LOOP1:
//JBC SEC,LP
MOV A,#1
ADD A,TL0
MOV TL0,A

MOV TH0,#70H
/*
SJMP LP1
LP:
MOV A,#05
ADD A,TL0
MOV TL0,A
MOV A,#19H
ADD A,TH0
MOV TH0,A

LP1: 

*/

   
POP ACC
POP PSW

RETI

end