#define F_CPU 7372800

#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>


void init_pwm (void)
{
TCCR0A=(1<<COM0A1)|(1<<WGM00);
TCCR0B=(1<<CS00);
OCR0A=0x00;
}

void pause (unsigned int a)
{
unsigned int i;
for (i=a;i>0;i--);
}

int main (void)
{

unsigned char i;
DDRD=0b01000000;

init_pwm();

while (1)
{
for (i=0;i<255;i++)
{
OCR0A++;
pause(1000);
}
for (i=0;i<255;i++)
{
OCR0A--;
pause(1000);
}
}

}