static void avr_watchdog_write(avr_t * avr, avr_io_addr_t addr, uint8_t v, void * param)
{
avr_watchdog_t * p = (avr_watchdog_t *)param;
// backup the registers
// uint8_t wd = avr->data[p->wdce.reg];
uint8_t wdce_o = avr_regbit_get(avr, p->wdce); // old
uint8_t wde_o = avr_regbit_get(avr, p->wde);
uint8_t wdp_o[4];
// printf("avr_watchdog_write %02x\n", v);
for (int i = 0; i < 4; i++)
wdp_o[i] = avr_regbit_get(avr, p->wdp[i]);
avr->data[p->wdce.reg] = v;
uint8_t wdce_n = avr_regbit_get(avr, p->wdce); // new
if (wdce_o /* || wdce_n */) {
// make sure bit gets reset eventually
if (wdce_n)
avr_cycle_timer_register(avr, 4, avr_wdce_clear, p);
uint8_t wdp = avr_regbit_get_array(avr, p->wdp, 4);
p->cycle_count = 2048 << wdp;
p->cycle_count = (p->cycle_count * avr->frequency) / 128000;
if (avr_regbit_get(avr, p->wde)) {
printf("Watchdog reset to %d cycles @ 128kz (* %d) = %d CPU cycles)\n", 2048 << wdp, 1 << wdp, (int)p->cycle_count);
avr_cycle_timer_register(avr, p->cycle_count, avr_watchdog_timer, p);
} else {
printf("Watchdog disabled\n");
avr_cycle_timer_cancel(avr, avr_watchdog_timer, p);
}
} else {
// reset old values
avr_regbit_setto(avr, p->wde, wde_o);
for (int i = 0; i < 4; i++)
avr_regbit_setto(avr, p->wdp[i], wdp_o[i]);
v = avr->data[p->wdce.reg];
}
avr_core_watch_write(avr, addr, v);
}
int
avr_clear_interrupt_if(
avr_t * avr,
avr_int_vector_t * vector,
uint8_t old)
{
if (avr_regbit_get(avr, vector->raised)) {
avr_clear_interrupt(avr, vector);
return 1;
}
avr_regbit_setto(avr, vector->raised, old);
return 0;
}
int
avr_clear_interrupt_if(
avr_t * avr,
avr_int_vector_t * vector,
uint8_t old)
{
avr_raise_irq(avr->interrupts.irq + AVR_INT_IRQ_PENDING,
avr_has_pending_interrupts(avr));
if (avr_regbit_get(avr, vector->raised)) {
avr_clear_interrupt(avr, vector);
return 1;
}
avr_regbit_setto(avr, vector->raised, old);
return 0;
}
/*
* prevent code from rewriting out status bits, since we actualy use them!
*/
static void
avr_twi_write_status(
struct avr_t * avr,
avr_io_addr_t addr,
uint8_t v,
void * param)
{
avr_twi_t * p = (avr_twi_t *)param;
uint8_t sr = avr_regbit_get(avr, p->twsr);
uint8_t c = avr_regbit_get(avr, p->twps);
avr_core_watch_write(avr, addr, v);
avr_regbit_setto(avr, p->twsr, sr); // force restore
if (c != avr_regbit_get(avr, p->twps)) {
// prescaler bits changed...
}
}