https://devzone.nordicsemi.com/f/nordic-q-a/14728/can-not-get-spi-control-back-after-ppiHello, I am trying to implement a clean shutdown process, but running into some issues. The flow of the SPI use is as listed here: Initialize SPI instance and program connected peripheral device via SPI. The calls being used are nrf_drv_spi_initen-USTelligent Community 13Fri, 24 Jun 2016 12:59:43 GMThttps://devzone.nordicsemi.com/thread/56210?ContentTypeID=1Fri, 24 Jun 2016 12:59:43 GMT137ad170-7792-4731-bb38-c0d22fbe4515:fc77252c-856c-4468-8cec-2fb6a296712dFI<p>Yes, I use nrf_drv_spi_uinit, just for test and debug this issue. After a little more checking, the issue appears to have something to do with Interrupts, I used nrf_spim_int_disable to disable interrupts in SPIM-PPI mode, and when getting back the control, I first tried to use nrf_spim_int_enable call to set interrupt enable with corresponding masks, but this seems to cause issue, I then used nrf_spim_int_disable with an all-zero mask, this seems to get the program going, at least the subsequent SPI read and writes would not hang in the while loop waiting for xfer_done flag, or return error with Busy_State if the while is bypassed. So, is it correct that the actual &quot;Enable&quot; and &quot;Disable&quot; is done by just the nrf_spim_int_disable call, and masked differently?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/56209?ContentTypeID=1Fri, 24 Jun 2016 12:22:10 GMT137ad170-7792-4731-bb38-c0d22fbe4515:0e73e03d-f956-428e-88c2-22aa6cabbd54&#216;yvind Karlsen<p>In 3c) are you using nrf_drv_spi_uninit?</p><div style="clear:both;"></div>