https://devzone.nordicsemi.com/f/nordic-q-a/25211/where-how-are-uart-interrupt-handlers-set-on-nrf52840SDK Version: 13 Alpha I&#39;ve been able to track down, through app_uart.h, where UART interrupt priorities are set using NVIC_SetPriority(). Now I&#39;d like to know where interrupts are mapped to there associated handler. I have already fruitlessly searcheden-USTelligent Community 13Fri, 15 Sep 2017 02:29:28 GMThttps://devzone.nordicsemi.com/thread/99357?ContentTypeID=1Fri, 15 Sep 2017 02:29:28 GMT137ad170-7792-4731-bb38-c0d22fbe4515:39e0a0e1-3c16-44dd-ae65-b95cc444ab14RK<p>No it&#39;s not hidden anywhere in any proprietary firmware. It&#39;s standard ARM Cortex interrupt handling.</p> <p>There&#39;s a vector table starting at 0x00000000 (well that&#39;s actually the stack pointer and the vector table starts at 0x00000004). That&#39;s populated with the xxxIRQHandler symbols which are mostly weakly defined to the same spin forever handler.</p> <p>If you define a routine with one of those names, it will be linked in instead and its address will be the one put in the table instead of the do-nothing handler.</p> <p>That&#39;s it - that&#39;s all there is. That table is populated in one of the .s files in the tools section of the SDK, depending on what tool you&#39;re using. The interrupt handler names are of course the same in each one.</p><div style="clear:both;"></div>