https://devzone.nordicsemi.com/f/nordic-q-a/3708/high-frequency-clock-requestIs it possible to modify the software in such a way that the nRF1822 sets a GPIO high when it requires its high frequency clock? We would like to avoid using an extra XTAL in our design, but don&#39;t want to leave the clock generator running when it isen-USTelligent Community 13Wed, 03 Sep 2014 07:32:25 GMThttps://devzone.nordicsemi.com/thread/13459?ContentTypeID=1Wed, 03 Sep 2014 07:32:25 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a009e953-be4d-4c9a-9621-a8348382da3aAsbj&#248;rn<p>Various peripherals in the chip requires the external 16 MHz to be running, but you could essentially add an extra line of code for the init/start calls for each of those peripherals. So that every time a peripheral needs 16XOSC a GPIO goes high. Have a look in chapter 8.3 of the <a href="https://www.nordicsemi.com/eng/nordic/download_resource/20339/11/12322603">nRF51822 product specification</a> for details on which peripheral requires external 16 MHz.</p><div style="clear:both;"></div>