https://devzone.nordicsemi.com/f/nordic-q-a/74044/nvmc-write-is-not-possible-after-softdevice-initializationHi, I want to write to the NVMC UICR Customer[n] memory addresses during code execution. I noticed that I can write/read/erase those addresses only before the initialization of the softDevice When I try to execute the same code after softDeviceen-USTelligent Community 13Fri, 16 Apr 2021 08:41:28 GMThttps://devzone.nordicsemi.com/thread/305233?ContentTypeID=1Fri, 16 Apr 2021 08:41:28 GMT137ad170-7792-4731-bb38-c0d22fbe4515:e7bb33ad-d0d5-4779-b484-e081cb28ff25J&#248;rgen Holmefjord<p>Hi,</p> <p>The softdevice will <a href="https://infocenter.nordicsemi.com/topic/sds_s140/SDS/s1xx/sd_resource_reqs/hw_block_interrupt_vector.html">restrict access to the NVMC peripheral</a> when it is enabled. See <a href="https://devzone.nordicsemi.com/f/nordic-q-a/72514/uicr-runtime-write/298707#298707">this post</a>.</p> <p>Note that the UICR CUSTOMER registers are mainly intended for parameters that are updated once or very seldom, as it is required to erase the full UICR to overwrite one register. For storing data that will be updated more often, you can write to flash through the Softdevice Flash API.</p> <p>Best regards,<br />Jørgen</p><div style="clear:both;"></div>