https://devzone.nordicsemi.com/f/nordic-q-a/47108/nrf51822-system-off-exit-sourcesHello everyone, I want to ask whether the NRF51822 can exit SYSTEM OFF mode with interrupt from a timer? In the user guide I read: The system can be woken up from System OFF mode either from the -DETECT signal (when active) generated by theen-USTelligent Community 13Thu, 09 May 2019 10:53:02 GMThttps://devzone.nordicsemi.com/thread/186147?ContentTypeID=1Thu, 09 May 2019 10:53:02 GMT137ad170-7792-4731-bb38-c0d22fbe4515:7b7fe6f8-785a-440a-9317-e594fd8c13edSigurd<p>Hi,</p> [quote userid="77810" url="~/f/nordic-q-a/47108/nrf51822-system-off-exit-sources"]I want to ask whether the NRF51822 can exit SYSTEM OFF mode with interrupt from a timer?[/quote] <p>No, that is not possible.&nbsp;In System OFF mode,&nbsp;the system&rsquo;s core functionality is powered down and all ongoing tasks are terminated. All clock sources are off during system off, so this includes both the RTC and TIMER&nbsp;peripheral.</p> [quote userid="77810" url="~/f/nordic-q-a/47108/nrf51822-system-off-exit-sources"]Are those the only interrupt sources that can wake up the chip?[/quote] <p>Yes.</p><div style="clear:both;"></div>