Reset button on nrf52840dk stopped working

[Oli]

It seems the "reset" button on my nrf52840dk doesn't do anything anymore. I believe this started happening after I enabled mcuboot in sysbuild. Is this expected?

[Jørgen Holmefjord]

Hi,

The reset pin is enabled by default for the nRF52840 DK in the uicr node in the devicetree. Have you modified or deleted this node in your board overlay files?

You can check the build devicetree file in the your build folder: build\<image_name>\zephyr\zephyr.dts. You might want to check both the application and the mcuboot image.

Once programmed, the UICR will be written by the application to enable the nRESET pin. You can check that this has been enabled correctly by reading out this registers using the debugger:

nrfjprog --memrd 0x10001200
nrfjprog --memrd 0x10001204

If nRESET is enabled correctly, the registers should read 0x00000012. 

Best regards,
Jørgen