#include<avr/io.h>
#define PortLED PORTA
#define CzasJednostkowy 65536-31250
int main(void)
{
DDRA=0xFF;

TCCR1B=(1<<CS12);


while(1)
    {
PortLED=PortLED^3;
TIFR|=(1<<TOV1);
TCNT1=CzasJednostkowy;
while(~TIFR&(1<<TOV1));
}
}