nRF53 Device is Protected after programming and I cannot debug

[nsga333]

When i program our new nRF5340 based radio boards the program returns Device Protected for both cores on completion. It is also impossible to debug the board as my segger refuses to connect.

I found a case with a similar issue:

https://devzone.nordicsemi.com/f/nordic-q-a/75406/problem-to-debug-net-cpu-after-segger-update-and-new-nrf5340-chip?ReplySortBy=CreatedDate&ReplySortOrder=Descending

and have tried the suggested solution of:

put the following in the NET Code at the start of main:

NRF_UICR_NS->APPROTECT=0x50fa50fa;
NRF_CTRLAP_NS->APPROTECT.DISABLE=0x50fa50fa;

put the following in the  APP Code the start of main:

NRF_UICR_S->APPROTECT=0x50fa50fa;
NRF_CTRLAP_S->APPROTECT.DISABLE=0x50fa50fa;

This does seem to allow the debugger to connect, However i get a hard fault from the command.

Is there a suggested way around this issue?

[Sigurd]

Hi,

How are you flashing the device? With nrfjprog or west?

Take a look at the commands on this page on how to flash the image:

http://developer.nordicsemi.com/nRF_Connect_SDK/doc/1.5.0/nrf/ug_nrf5340.html#programming-from-the-command-line

[emag nioj]

I m stuck i try to attach the debug the flash erases. Sometime it works other not.

I have the NET core that needs to update the firmware flash and it's impossible to debug it.

problems:

- it's not clear if it's possible to write the NET core from the APP core in case of yes it makes firmware update simpler.

- it's not clear how to disable protection from firmware to let debug to attach in NET core

- the info in the datasheet are not clear about lot of protect and disable protect and flash uicr bah!!!!

I'll abandon nr5340 to many time wasted in problems not related to the development of the code

bye