How to force device reset after DFU update (NRF52832)

[bgarrood]

In my DFU bootloader I am protecting areas of Flash memory used to store user data.

After an update, when my application starts and tries to write to this memory it is causing a fault because memory is still protected.  

I understand that the flash memory protection is only cleared on a reset, and the DFU doesn't automatically force a reset of the device.  How can I clear the flash memory protection?

[Einar Thorsrud]

Hi,

You do not write how you protect the flash memory, but I assume it is using BPROTon the nRF52832? If so, then the only way to disable it is to reset (typically calling NVIC_SystemReset() or sd_nvic_SystemReset()), and you should make sure to not enable it again after the reset (signal that using a retention register or something else).

[bgarrood]

Thank you.  I think I misunderstood how the dfu bootloader works - I think it always runs but ordinarily pings you straight into main code, so this was setting the BPROT flags even after a reset.  i have reordered things now.  Thank you!