https://devzone.nordicsemi.com/f/nordic-q-a/47532/clock-running-on-power-resetHi, In the documentation nFR523832_PS_v1.4, on page 107, the registers HFCLKSTAT and LFCLKSTAT when in reset mode, indicates that the LFCLK is not runing, and neither the HFCLK, if no clock is runing, how can the &#181;C leave the reset mode and go to CPUen-USTelligent Community 13Tue, 21 May 2019 01:15:05 GMThttps://devzone.nordicsemi.com/thread/188051?ContentTypeID=1Tue, 21 May 2019 01:15:05 GMT137ad170-7792-4731-bb38-c0d22fbe4515:41dfe403-8659-4164-b146-3e362817efa4RK<p>The internal LC clock runs to run the CPU. If you enable the HFCLK (which you only need to do for some operations) the CPU will use that in preference, else it just starts the internal LC. This is under the clock section in that documentation.&nbsp;</p><div style="clear:both;"></div>