fepin.asm

单片机开发资料光盘-双龙-686M.zip

         .include "8515def.inc" 
         .cseg
	  .org 0x00
	   rjmp reset
           reti
	   reti
	   reti
	   reti
	   reti
	   reti	   		 		
	  .org 0x09
	   rjmp tim0_ovf

	 reset:nop
                ldi r16,low(ramend)
		out spl,r16
		ldi r16,high(ramend)
		out sph,r16
		ldi r16,0
		out porta,r16
		out portb,r16
		out portc,r16
		out portd,r16
		out ddra,r16
		out ddrb,r16
		out ddrc,r16
		out ddrd,r16
	        sbi ddrd,5
		ldi r17,250
		out TCNT0,r17
		ldi r17,1
		out TCCR0,r17
		ldi r17,2
		out TIMSK,r17
		ldi r18,0
		sei
        round:	
		sbis pind,6
		rjmp set1	
		rjmp set2
        set1:  ldi r21,2
		out TCCR0,r21
		rjmp round
        set2:ldi r21,1
		out TCCR0,r21
                rjmp round


       tim0_ovf:in r20,sreg		
		ldi r17,250
		out TCNT0,r17
		cpi r18,1
		breq  low
		sbi portd,5
		ldi r18,1
		rjmp gogo
         low:   cbi portd,5
		clr r18
	  gogo:	out sreg,r20
		reti

                nop
		nop
		nop
		rjmp reset