https://devzone.nordicsemi.com/f/nordic-q-a/4447/can-t-write-rbpconfi want to prevent somebody to copy my app by SWD interface,so i set RBPCONF register in main application,but i find that it is no use writing RBPCONF register. First ,i write 0xFFFF0000 to RBPCONF register(NRF_UICR-&gt;RBPCONF =0xFFFF0000;),Then i readen-USTelligent Community 13Thu, 13 Nov 2014 13:52:29 GMThttps://devzone.nordicsemi.com/thread/15791?ContentTypeID=1Thu, 13 Nov 2014 13:52:29 GMT137ad170-7792-4731-bb38-c0d22fbe4515:f4eedc66-4daf-419e-9152-945827fac308Asbj&#248;rn<p>The UICR register is placed in flash so you can&#39;t access is directly like you are trying to do. Instead you must do a flash write operations. If you&#39;re not using a softdevice you can set this register by writing:</p> <pre><code>nrf_nvmc_write_word(0x10001004, 0xFFFF0000); </code></pre> <p><a href="https://devzone.nordicsemi.com/documentation/nrf51/6.1.0/s110/html/a00937.html#ga8b49f2e72e97291aecc18ce396956eed">If you are using a softdevice you can write to the same register by using the softdevice wrapper function:</a></p> <pre><code>sd_flash_write() </code></pre><div style="clear:both;"></div>