https://devzone.nordicsemi.com/f/nordic-q-a/1586/cpu-lock-up-detectedDear Sir, I used nRF51822, I found sometime the program reset itselft. Then I made a test program to send out the &quot;RESET REASON&quot;by BLE message. I found the reset reason = 0x1000C. refer to &quot;AIRCR.SYSRESETREQ&quot;&amp; &quot;CPU lock-up&quot; detected. I want to knowen-USTelligent Community 13Wed, 12 Feb 2014 09:51:44 GMThttps://devzone.nordicsemi.com/thread/7022?ContentTypeID=1Wed, 12 Feb 2014 09:51:44 GMT137ad170-7792-4731-bb38-c0d22fbe4515:ff1aea76-9c73-4fc8-a290-743559c46360Ole Morten<p>Also see PAN item 41: POWER: RESETREAS register may erroneously indicate LOCKUP. In summary, the lockup you see can&#39;t be trusted when other bits in RESETREAS are also set.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/7021?ContentTypeID=1Tue, 11 Feb 2014 13:58:53 GMT137ad170-7792-4731-bb38-c0d22fbe4515:453c4ade-ed07-4965-bf64-b5831a77fc42H&#229;kon Alseth<p>Hi,</p> <p>That indicates that your device is reset using a software reset (NVIC_SystemReset();). It&#39;s most likely due to a assert somewhere in your application.</p> <p>Check function &quot;app_error_handler&quot; and comment in &quot;ble_debug_assert_handler&quot; to get more information.</p> <p>Best regards Håkon</p><div style="clear:both;"></div>