https://devzone.nordicsemi.com/f/nordic-q-a/6317/ppi-with-uarthi, I am using the nrf51422 for the first time. I need to connect a GSM-GPS module for reading nmea string. I have to use the uart to enable communication with the GPS and I would use the interface ppi to capture the data and put them in a buffer untilen-USTelligent Community 13Wed, 01 Apr 2015 00:15:17 GMThttps://devzone.nordicsemi.com/thread/22042?ContentTypeID=1Wed, 01 Apr 2015 00:15:17 GMT137ad170-7792-4731-bb38-c0d22fbe4515:95c39241-1e81-444a-ad71-1be7c0622f26RK<p>No that&#39;s not possible. There&#39;s no DMA on the chip (well apart from the SPI slave which isn&#39;t what you want to use). So the CPU has to be woken up to deal with each byte as it comes in and clear the receive event so the UART can read the next.</p> <p>This shouldn&#39;t however be a problem, you can run it in a low-power mode where the CPU is off until you get an interrupt and wakes up just to receive a byte, that&#39;s not much work, and the HF clock is running already if the UART is on.</p> <p>Why do you not want the CPU involved?</p><div style="clear:both;"></div>