// Timer/Counter 0 initialization
// Clock source: System Clock
// Clock value: 8000,000 kHz
// Mode: CTC top=OCR0A
// OC0A output: Toggle on compare match
// OC0B output: Disconnected
TCCR0A=0x42;
TCCR0B=0x01;
TCNT0=0x00;
OCR0A=0x04;
OCR0B=0x00;