https://devzone.nordicsemi.com/f/nordic-q-a/51949/low-power-mode-and-rtc-timer-and-ppiSDK15.3 nRF52840 S140 v6.1.1 Q1. I have an RTC compare event connected to a Timer count task over PPI. The Timer is configured in low power counter mode. My question is when I go into low power mode using sd_app_evt_wait(), will the RTC eventsen-USTelligent Community 13Tue, 10 Sep 2019 09:02:17 GMThttps://devzone.nordicsemi.com/thread/208843?ContentTypeID=1Tue, 10 Sep 2019 09:02:17 GMT137ad170-7792-4731-bb38-c0d22fbe4515:cc412b4e-034b-4f49-af94-0821166488bchaakonsh<p>Q1)<br /><span>sd_app_evt_wait() will put the MCU into SystemON Idle, where the CPU is at sleep but the peripheral sub-system is awake. This means that all peripherals are available, with PPI and EasyDMA. Anything running before you call&nbsp;sd_app_evt_wait() will continue to do so. If a peripheral requires the CPU to run a driver the CPU will be woken up.&nbsp;<br /><br /></span>Q2)<br />Yes, because the PPI system requires the 16MHz clock tree, who&#39;s a division of the HFCLK clock. &#39;Low power mode&#39; means that the HFCLK is turned off/on on-demand, vs &#39;constant latency&#39; where the HFCLK is always on to force a constant latency of the wake-up times of peripherals and CPU.&nbsp;</p><div style="clear:both;"></div>