RTC1 forever counter (64 bits). Detect RTC1 overflow with S130

Question

Can I detect overflow on RTC1 when using timers with S130?
In my App, I use timers but also count time with NRF_RTC1->COUNTER. I need to know If overflow happens.
It seems that the IRQHandler doesn't mather about event. 
 void RTC1_IRQHandler(void)
{
// Clear all events (also unexpected ones)
NRF_RTC1->EVENTS_COMPARE[0] = 0;
NRF_RTC1->EVENTS_COMPARE[1] = 0;
NRF_RTC1->EVENTS_COMPARE[2] = 0;
NRF_RTC1->EVENTS_COMPARE[3] = 0;
NRF_RTC1->EVENTS_TICK = 0;
NRF_RTC1->EVENTS_OVRFLW = 0; 
 // Check for expired timers
timer_timeouts_check();
 
 }

oscarsan · Accepted Answer

Ok, thanks. Too difficult to understand. I do instead a 64 bits counter based on OVERFLOW event counter. Calling a new function return a long term 64 bits for ever counter.

New variable for overflow counter:

static uint32_t 											RTC1_overflow_counter=0x0;			// Counts number overflows

Adding and Event ant interruption overflow:

static void rtc1_start(void){

NRF_RTC1->EVTENSET = RTC_EVTEN_COMPARE0_Msk | RTC_EVTEN_OVRFLW_Msk;;
NRF_RTC1->INTENSET = RTC_INTENSET_COMPARE0_Msk | RTC_INTENSET_OVRFLW_Msk;

	NVIC_ClearPendingIRQ(RTC1_IRQn);
NVIC_EnableIRQ(RTC1_IRQn);

NRF_RTC1->TASKS_START = 1;
nrf_delay_us(MAX_RTC_TASKS_DELAY);

m_rtc1_running = true;}

Counting overflows in the IRQ:

void RTC1_IRQHandler(void){
// Clear all events (also unexpected ones)
	if (NRF_RTC1->EVENTS_OVRFLW){
		RTC1_overflow_counter++;
	}     
NRF_RTC1->EVENTS_COMPARE[0] = 0;
NRF_RTC1->EVENTS_COMPARE[1] = 0;
NRF_RTC1->EVENTS_COMPARE[2] = 0;
NRF_RTC1->EVENTS_COMPARE[3] = 0;
NRF_RTC1->EVENTS_TICK       = 0;
NRF_RTC1->EVENTS_OVRFLW     = 0;
timer_timeouts_check();}

And the function for returning the 64 bits counter. Billions of years counter.

uint32_t app_timer_cnt_get64(uint64_t * p_ticks){
*p_ticks = (((uint64_t)RTC1_overflow_counter) << 24) + NRF_RTC1->COUNTER;
return NRF_SUCCESS;}

I test it and I think it works well. I'm not sure if doesn't mather calling timer_timeouts_check() at OVERFLOW interrupts, I think so.

RTC1 forever counter (64 bits). Detect RTC1 overflow with S130

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