nrf Dev kit do not start external oscillator

[nirmal@nordic]

hi, Everyone,

I was just checking on nrf51422 Dev kit for LFCLK and HFCLK oscillator configuration.

with lfclk set to start external oscillator ,it does not start external 16Mhz oscillator as HFCLKSTAT remains to 0x10000(which is internal RC oscillator) with breakpoint set after LFCLK initialization. Though, I can see advertised data in the Master control panel.

But, According to the nrf51422 product specification - chapter 8.3, it requires external oscillator for Radio to work...

so, how can it work in my case , if it is not starting external HF oscillator ????? What is the catch here ?

[RK]

Why would you expect that setting the LFCLOCK to use an external oscillator would start the 16MHz HFCLOCK oscillator? The two are entirely different things. If you check the LFCLOCK registers after starting the LF clock instead of checking the HF clock registers it might make more sense.

Indeed it does need an external 16MHz oscillator to use the radio, which just means it turns the HF oscillator on and off when it wants to use the radio.

[nirmal@nordic]

Exactly my point, RK, if I am not making any changes to HFCLK selection, why HFCLKSTAT is changing for different LFCLK sources ??