Flash/ROM area that are not erased at a flash erase.https://devzone.nordicsemi.com/f/nordic-q-a/126515/flash-rom-area-that-are-not-erased-at-a-flash-eraseI&#39;m creating a system test for manufactured units and if it&#39;s OK I would like to set a permanent flag in an area that will not be erased if I erase flash at a firmware update. Are there any such memory areas I can use?en-USTelligent Community 13Wed, 14 Jan 2026 14:49:08 GMTRE: Flash/ROM area that are not erased at a flash erase.https://devzone.nordicsemi.com/thread/558715?ContentTypeID=1Wed, 14 Jan 2026 14:49:08 GMT137ad170-7792-4731-bb38-c0d22fbe4515:ba1323e4-9393-4868-bc7c-ad285c2de140Syed Maysum Abbas Zaidi<p>Hi,</p> <p>On nRF52840, a normal firmware update (DFU) erases the application flash. So If you need to store a permanent flag that is not erased when flash is erased during a firmware update, the recommended solution is to store it in UICR (User Information Configuration Registers). UICR is not affected by firmware updates (DFU).</p> <p>Best Regards,<br />Syed Maysum</p><div style="clear:both;"></div>