You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

52 lines
1.4 KiB

/* gc_n64_usb : Gamecube or N64 controller to USB firmware
Copyright (C) 2007-2016 Raphael Assenat <>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <>.
#include <avr/io.h>
#include "intervaltimer.h"
void intervaltimer_init(void)
TCCR1A = 0;
TCCR1B = (1<<WGM12) | (1<<CS12) | (1<<CS00); // CTC, /1024 prescaler
void intervaltimer_set(int interval_ms)
static int cur_interval = 0;
// We are setting TCNT back to zero, and updating
// the compare match register.
// To allows for simple repeated calling of this
// function from the main loop, only touch
// the counter when the interval changes.
if (cur_interval != interval_ms) {
cur_interval = interval_ms;
TCNT1 = 0;
OCR1A = interval_ms * (F_CPU/1024) / 1000;
char intervaltimer_get(void)
if (TIFR1 & (1<<OCF1A)) {
TIFR1 = 1<<OCF1A;
return 1;
return 0;