inv-sw-32u4/src/timer.c

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

#include "include/timer.h"

void initCtcTimer0(void)
{
	/* Initialize counter 0 */
	TCNT0 = 0;

	/* Enable Counter0 Compare Match A Interrupt */
	TIMSK0 |= (1 << OCIE0A);
	
	/* Select clock. Prescaler of 8 */
	TCCR0B |= (1 << CS02) | (1 << CS00);
	
	/* Use CTC Mode */
	TCCR0A |= (1 << WGM01);

	/* 
	 * OCR0A contains TOP value for counter:
	 */
	OCR0A = 100;
}

void initOverflowTimer0(void)
{
	/* Prescaler = 0 */
	TCCR0B |= (1<<CS00);

	/* Enable Timer Overflow Interrupt */
	TIMSK0 |= (1<<TOIE0);
}

void initOverflowTimer1(void)
{
	TCCR1B |= (1<<CS11);
	TIMSK1 |= (1<<TOIE1);
}

ISR(TIMER0_COMPA_vect)
{
	PORTB |= (1 << PB2);
}