circuitpython/atmel-samd/tick.c

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#include "autoreset.h"
#include "tick.h"
#include "asf/sam0/drivers/tc/tc_interrupt.h"
// Global millisecond tick count
volatile uint64_t ticks_ms = 0;
static struct tc_module ms_timer;
static void ms_tick(struct tc_module *const module_inst) {
// SysTick interrupt handler called when the SysTick timer reaches zero
// (every millisecond).
ticks_ms += 1;
#ifdef AUTORESET_DELAY_MS
autoreset_tick();
#endif
}
void tick_init() {
struct tc_config config_tc;
tc_get_config_defaults(&config_tc);
config_tc.counter_size = TC_COUNTER_SIZE_16BIT;
config_tc.clock_prescaler = TC_CLOCK_PRESCALER_DIV1;
tc_set_top_value(&ms_timer, system_cpu_clock_get_hz() / 1000);
tc_init(&ms_timer, TC5, &config_tc);
tc_enable(&ms_timer);
tc_register_callback(&ms_timer, ms_tick, TC_CALLBACK_OVERFLOW);
tc_enable_callback(&ms_timer, TC_CALLBACK_OVERFLOW);
tc_start_counter(&ms_timer);
}