https://devzone.nordicsemi.com/f/nordic-q-a/123391/using-grtc-as-real-time-clockWe are just kicking off a new design with a nRF54L15. We would like to use the GRTC as a pseudo real-time-clock. We know that it retains its value through a reset and in system OFF state, so it should do the job for our purposes and save the cost anden-USTelligent Community 13Thu, 31 Jul 2025 14:07:41 GMThttps://devzone.nordicsemi.com/thread/544230?ContentTypeID=1Thu, 31 Jul 2025 14:07:41 GMT137ad170-7792-4731-bb38-c0d22fbe4515:4d2d6199-9a2c-4afb-b270-9412f9b25af5H&#229;kon Alseth<p>Hi,</p> <p>&nbsp;</p> [quote user=""]Or perhaps Zephyr does not reset the counter on power up and we can still use it as a continuous counter through resets?[/quote] <p>GRTC is reset under certain states (see the nRF54L15 datasheet: <a href="https://docs.nordicsemi.com/bundle/ps_nrf54L15/page/chapters/power-and-clock/reset/doc/reset.html#ariaid-title11">https://docs.nordicsemi.com/bundle/ps_nrf54L15/page/chapters/power-and-clock/reset/doc/reset.html#ariaid-title11</a>), but wakeup from system off can retain the GRTC counter. See here for an example of this:</p> <p>&nbsp;<a href="https://devzone.nordicsemi.com/f/nordic-q-a/123277/issue-regarding-the-configuration-of-grtc-in-nrf54l15-dk/543893">RE: Issue regarding the Configuration of GRTC in nRf54L15-DK</a>&nbsp;</p> <p>&nbsp;</p> <p>Kind regards,</p> <p>Håkon</p><div style="clear:both;"></div>