53 lines
1.4 KiB
C
53 lines
1.4 KiB
C
/* gc_n64_usb : Gamecube or N64 controller to USB firmware
|
|
Copyright (C) 2007-2015 Raphael Assenat <raph@raphnet.net>
|
|
|
|
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
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
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 <http://www.gnu.org/licenses/>.
|
|
*/
|
|
#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;
|
|
}
|