mirror of
https://github.com/raphnet/gc_n64_usb-v3
synced 2024-11-14 05:05:07 -05:00
38 lines
702 B
C
38 lines
702 B
C
|
#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;
|
||
|
|
}
|