Delay between nrf_drv_uart_rx_abort (sends NRF_UARTE_TASK_STOPRX) to enter to event handler.

[VadymS]

Hi.

I work with PCA10040 and SKD_14.2. 

I use UARTE with easy DMA.
I see big enough delay between sending nrf_drv_uart_rx_abort and entering to UART event hanler. What is the latency should be in this case?

Thanks.

[Susheel Nuguru]

The smallest interrupt latency on Cortex M4 is 12 CPU cycles. There could be few more cycles added on chip design when adding more peripheral lines.

If you see significantly more latency, then it means that the CPU was busy handling other handler which is clearly higher in priority than the UART interrupt handler.