TimerTest01.c

#include <avr/io.h>

#include <avr/interrupt.h>

int main(void)

{

  //Timer0 Config

  TCCR0A |= (1 << WGM01);         // Timer0 in CTC Mode   

  OCR0A  = 20;              // CTC-Wert auf 20 - 4MHz/20=200kHz

  TCCR0A |= (1 << COM0B0);        // Toggle OC0A on Compare Match  

  TCCR0B |=  (1 << CS00);          // Timertakt = FCPU

  TIMSK |= (1 << OCIE0A);         // Enable CTC interrupt  

  sei();

  while(1)

  {

  } 

  return 0;

}