Possible bug in nrf52832 LFCLK

[KLWP0101]

[Bug Report] Possible bug in nRF52832 engineering release B. When LF XTAL oscillator is started, no event is generated.

NRF_CLOCK->LFCLKSRC = CLOCK_LFCLKSRC_SRC_Xtal;
NRF_CLOCK->TASKS_LFCLKSTART = 1;
while (NRF_CLOCK->EVENTS_LFCLKSTARTED == 0)   { };      // STUCK HERE FOREVER!!

The oscillator is actually started but no event is generated.

[Susheel Nuguru]

updated with code that worked (29.01.2016)

Maybe it needs one clk cycle or two between selection of the clock source and starting the lfclk, try this below

NRF_CLOCK->EVENTS_LFCLKSTARTED = 0;
NRF_CLOCK->LFCLKSRC = (CLOCK_LFCLKSRC_SRC_Xtal << CLOCK_LFCLKSRC_SRC_Pos);
__DSB();     //<-- This will wait until write buffers are emptied.
NRF_CLOCK->TASKS_LFCLKSTART = 1;
while (NRF_CLOCK->EVENTS_LFCLKSTARTED == 0)
{
}

i do not have engineering sample B to test it with. If the above code works, then i should ask someone here to test out why the event missed.

[Susheel Nuguru]

RK, but he said that it is stuck in the while loop for ever, that is the part that confused me. If it is the write buffer then it should have exited the while loop in few cycles.