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#include "opnatimer.h"
#include "opna.h"
enum {
TIMERA_BITS = 10,
TIMERB_SHIFT = 4,
TIMERB_BITS = 8 + TIMERB_SHIFT,
};
void opna_timer_reset(struct opna_timer *timer, struct opna *opna) {
timer->opna = opna;
timer->status = 0;
timer->interrupt_cb = 0;
timer->interrupt_userptr = 0;
timer->mix_cb = 0;
timer->mix_userptr = 0;
timer->timerb = 0;
timer->timerb_load = false;
timer->timerb_enable = false;
timer->timerb_cnt = 0;
}
uint8_t opna_timer_status(const struct opna_timer *timer) {
return timer->status;
}
void opna_timer_set_int_callback(struct opna_timer *timer, opna_timer_int_cb_t func, void *userptr) {
timer->interrupt_cb = func;
timer->interrupt_userptr = userptr;
}
void opna_timer_set_mix_callback(struct opna_timer *timer, opna_timer_mix_cb_t func, void *userptr) {
timer->mix_cb = func;
timer->mix_userptr = userptr;
}
void opna_timer_writereg(struct opna_timer *timer, unsigned reg, unsigned val) {
val &= 0xff;
opna_writereg(timer->opna, reg, val);
switch (reg) {
case 0x24:
timer->timera &= ~0xff;
timer->timera |= val;
break;
case 0x25:
timer->timera &= 0xff;
timer->timera |= ((val & 3) << 8);
break;
case 0x26:
timer->timerb = val;
timer->timerb_cnt = timer->timerb << TIMERB_SHIFT;
break;
case 0x27:
timer->timera_load = val & (1<<0);
timer->timera_enable = val & (1<<2);
timer->timerb_load = val & (1<<1);
timer->timerb_enable = val & (1<<3);
if (val & (1<<4)) {
timer->status &= ~(1<<0);
}
if (val & (1<<5)) {
//timer->timerb_cnt = timer->timerb << TIMERB_SHIFT;
timer->status &= ~(1<<1);
}
}
}
#include <stdio.h>
#include <stdlib.h>
void opna_timer_mix(struct opna_timer *timer, int16_t *buf, unsigned samples) {
do {
unsigned generate_samples = samples;
if (timer->timerb_enable && timer->timerb_load) {
unsigned timerb_samples = (1<<TIMERB_BITS) - timer->timerb_cnt;
if (timerb_samples < generate_samples) {
generate_samples = timerb_samples;
}
}
if (timer->timera_enable && timer->timera_load) {
unsigned timera_samples = (1<<TIMERA_BITS) - timer->timera;
if (timera_samples < generate_samples) {
generate_samples = timera_samples;
}
}
opna_mix(timer->opna, buf, generate_samples);
if (timer->mix_cb) {
timer->mix_cb(timer->mix_userptr, buf, generate_samples);
}
buf += generate_samples*2;
samples -= generate_samples;
if (timer->timera_load) {
timer->timera = (timer->timera + generate_samples) & ((1<<TIMERA_BITS)-1);
if (!timer->timera && timer->timera_enable) {
if (!(timer->status & (1<<0))) {
timer->status |= (1<<0);
timer->interrupt_cb(timer->interrupt_userptr);
}
}
timer->timera &= (1<<TIMERA_BITS)-1;
}
if (timer->timerb_load) {
timer->timerb_cnt = (timer->timerb_cnt + generate_samples) & ((1<<TIMERB_BITS)-1);
if (!timer->timerb_cnt && timer->timerb_enable) {
if (!(timer->status & (1<<1))) {
timer->status |= (1<<1);
timer->interrupt_cb(timer->interrupt_userptr);
}
}
}
} while (samples);
}
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