8515pwm.asm

单片机开发资料光盘-双龙-686M.zip

;用AT90S8515的PWM控制直流电机调速
.include"8515def.inc"	;
.def temp=r16
.def temp1=r19
.def result=r17
.def temp2=r18
.org $0000
      rjmp reset
.org $0030
reset:	ldi temp,$02
	out sph,temp
	ldi temp,$5f
	out spl,temp
	ldi r20,$ff     ;设置c口为输出
	out ddrc,r20
	ldi r20,$f0
	out ddrb,r20
	out portb,r20
	clr r20
	out portc,r20
adc:	clr temp	
loop1:	out portc,temp
	nop
	nop
	nop
	in temp1,acsr
	sbrs temp1,$05
	rjmp naco
	rjmp haco
naco:	inc temp
	brne loop1
	ldi temp,$ff
haco:   mov result,temp
	ldi temp,0b00100001	;上数达到OC1B=0下数达到OC1B=1。8位PWM模式。
	out tccr1a,temp
	ldi temp,0b00000010	;采用CK/8分频。
	out tccr1b,temp
	ldi temp,$00		;设置$0150
	out ocr1bh,temp
	out ocr1bl,result
	rcall del
	rjmp adc
del:	ldi temp2,10		;延时子程序
del1:	push temp2
del2:	push temp2
del3:	push temp2
del4:	dec temp2
	brne del4
	pop temp2
	dec temp2
	brne del3
	pop temp2
	dec temp2
	brne del2
	pop temp2
	dec temp2
	brne del1
	ret