RE: SoftDevice and TIMER interrupts

Håkon Alseth — Wed, 23 Apr 2014 13:22:32 GMT

Hi Marcel,

If you have tasks that are very timing critical, you can make sure that the HFCLK is running via these functions in nrf_soc.h:


SVCALL(SD_CLOCK_HFCLK_REQUEST, uint32_t, sd_clock_hfclk_request(void));
SVCALL(SD_CLOCK_HFCLK_RELEASE, uint32_t, sd_clock_hfclk_release(void));
SVCALL(SD_CLOCK_HFCLK_IS_RUNNING, uint32_t, sd_clock_hfclk_is_running(uint32_t * p_is_running));

sd_clock_hfclk_request() will generate an event "NRF_EVT_HFCLKSTARTED" or you can poll using sd_clock_hfclk_is_running().

There are a couple of posts already on how to start a timer: devzone.nordicsemi.com/.../setting-timer2-interval

Regarding "NRF_CLOCK->TASKS_HFCLKSTART = 1;", if you do this after the stack is initialized, you will end up in the hardfault handler, as this is a restricted peripheral (softdevice owns it)

Best regards Håkon