https://devzone.nordicsemi.com/f/nordic-q-a/72514/uicr-runtime-writeHi, What is the correct way to write to UICR at runtime? I am using the code below but the MCU crashes on the first line with no call stack trace. NRF_NVMC-&gt;CONFIG = NVMC_CONFIG_WEN_Wen &lt;&lt; NVMC_CONFIG_WEN_Pos ; while (NRF_NVMC-&gt;READY == NVMC_READY_READY_Busyen-USTelligent Community 13Fri, 12 Mar 2021 09:15:06 GMThttps://devzone.nordicsemi.com/thread/299411?ContentTypeID=1Fri, 12 Mar 2021 09:15:06 GMT137ad170-7792-4731-bb38-c0d22fbe4515:b32b38b8-f860-4696-b285-ecf059a76d32Dermot Murphy<p>Hi Jorgen,</p> <p>Thanks for the info.</p> <p>Dermot</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/298707?ContentTypeID=1Tue, 09 Mar 2021 13:01:25 GMT137ad170-7792-4731-bb38-c0d22fbe4515:fc9f9078-8bb1-47d5-9aa9-74c9da6af1d8J&#248;rgen Holmefjord<p>Hi,</p> <p>Are you using a softdevice in your application? If you are, then all access to the NVMC peripheral needs to go through the <a href="https://infocenter.nordicsemi.com/topic/sds_s140/SDS/s1xx/flash_mem_api/flash_mem_api.html">Flash API</a>.</p> <p>There is no API to write UICR while the softdevice is enabled, you need to disable the softdevice and re-enable it once writing is done.</p> <p>Best regards,<br />Jørgen</p><div style="clear:both;"></div>