pwm.c

一个通过串口与51通信的AVR的程序,还有一些其实功能

#include <header.h>
#include <PWM.h>


void PWM(unsigned char top,unsigned char match,unsigned char freq_prev)
{
TCNT2=top;//0x00;
OCR2=match;//0xf0;
switch(freq_prev)
	{
	case 0:TCCR2=(1<<WGM21)|(1<<WGM20)|(1<<COM21)|(1<<COM20)|(0<<CS22)|(0<<CS21)|(0<<CS20);PORTD&=0x7f;break;
	case 1:TCCR2=(1<<WGM21)|(1<<WGM20)|(1<<COM21)|(1<<COM20)|(0<<CS22)|(0<<CS21)|(1<<CS20);break;
	case 2:TCCR2=(1<<WGM21)|(1<<WGM20)|(1<<COM21)|(1<<COM20)|(0<<CS22)|(1<<CS21)|(0<<CS20);break;
	case 3:TCCR2=(1<<WGM21)|(1<<WGM20)|(1<<COM21)|(1<<COM20)|(0<<CS22)|(1<<CS21)|(1<<CS20);break;
	case 4:TCCR2=(1<<WGM21)|(1<<WGM20)|(1<<COM21)|(1<<COM20)|(1<<CS22)|(0<<CS21)|(0<<CS20);break;
	case 5:TCCR2=(1<<WGM21)|(1<<WGM20)|(1<<COM21)|(1<<COM20)|(1<<CS22)|(0<<CS21)|(1<<CS20);break;
	case 6:TCCR2=(1<<WGM21)|(1<<WGM20)|(1<<COM21)|(1<<COM20)|(1<<CS22)|(1<<CS21)|(0<<CS20);break;
	case 7:TCCR2=(1<<WGM21)|(1<<WGM20)|(1<<COM21)|(1<<COM20)|(1<<CS22)|(1<<CS21)|(1<<CS20);break;
	}
}