RTC1 interrupt does't trigger, and what's event counter?

RE: RTC1 interrupt does't trigger, and what's event counter?

FormerMember — Mon, 19 Jun 2017 13:21:54 GMT

For the EVENTS_LFCLKSTARTED to trigger, the NRF_CLOCK->INTENSET register has to be set.

RE: RTC1 interrupt does't trigger, and what's event counter?

akita — Sat, 17 Jun 2017 23:55:28 GMT

I've checked LFCLK status for details (in main(), after mbed's startup and initialization codes), by reading related register as follows:

NRF_CLOCK->LFCLKRUN 0x1 : task triggered
NRF_CLOCK->LFCLKSTAT 0x10000 : LFCLK running, src=RC osc
NRF_CLOCK->EVENTS_LFCLKSTARTED 0x0 : LFCLK not started?
NRF_CLOCK->LFCLKSRC 0x0 : src=RC osc
NRF_CLOCK->LFCLKSRCCOPY 0x0 : src=RC osc

LFCLKSTAT=0x10000 means that LFCLK is running with RC oscillarator, however, I wonder that EVENTS_LFCLKSTARTED is 0x0...?

RE: RTC1 interrupt does't trigger, and what's event counter?

FormerMember — Thu, 15 Jun 2017 13:13:27 GMT

Before starting the LFCLK, it has to be configured, by setting the clock source and the CTIV. CTIV should only be necessary if the internal RC oscillator is being used. To start the LFCLK you should do the following:

NRF_CLOCK->LFCLKSRC = clock source
NRF_CLOCK->CTIV     = ...
NRF_CLOCK->TASKS_LFCLKSTART = 1;
while(EVENTS_LFCLKSTARTED == 0)
{
}
// continue

Could you check if making sure that the LFCLK is running change anything?

I wouldn't think that the RTC would increment if the LFCLK is not running..but if it is incrementing while the clock is not running, I would think it is quite unreliable.

RE: RTC1 interrupt does't trigger, and what's event counter?

akita — Wed, 14 Jun 2017 23:32:04 GMT

I've checked LFCLKSTAT indicates that LFCLK is not running. I've tried to start it (writing 1 to LFCLKSTART), but LFCLKSTAT still indicates that LFCLK is not running. I'll continue to debug it, but I wonder that RTC1 actually increments, even if LFCLK seems to not running; this is right?

RE: RTC1 interrupt does't trigger, and what's event counter?

FormerMember — Wed, 14 Jun 2017 11:43:58 GMT

Could you double check if the LFCLK is running by reading the LFCLKSTAT register? That will make the debugging easier.

RE: RTC1 interrupt does't trigger, and what's event counter?

akita — Wed, 14 Jun 2017 05:54:28 GMT

Yes, I'm sure LFCLK has started in startup routine in mbed (I'm using mbed-compiler for programming). Does RTC1's counter increments even if LFCLK doesn't start? (In my situation ,I've confirmed that RTC1's counter increments at specified speed by prescaler.)

RE: RTC1 interrupt does't trigger, and what's event counter?

Turbo J — Tue, 13 Jun 2017 11:20:41 GMT

EVENTS_TICK register will never contain any other value than 1 or 0.

RE: RTC1 interrupt does't trigger, and what's event counter?

FormerMember — Tue, 13 Jun 2017 11:16:07 GMT

Did you remember to start the LFCLK before starting the RTC?