recover nrf52 DK

[Neum_d]

Hi all!

I just bought a new nrf52DK: PCA10040, 3.0.0, 2023.10
If I want to flash my SW into it, nrfjprog says

ERROR: The operation attempted is unavailable due to readback protection in
ERROR: your device. Please use --recover to unlock the device.

So I run nrfjprog --recover -f nrf52.
After that, I try to flash my FW, but nrfjprog returns

ERROR: The file specified is not a valid hex file, has data outside valid areas
ERROR: or does not have data in valid areas.

If I plug off the DK and replace it by my old nrf52 DK (PCA10040, 1.2.4, 2019.8), I have no
problems to flash my SW, so the hex file itself should be valid. Does the new DK
require more parameters to nrfjprog?

Additional, if I replace the old DK with the new DK again, the new DK is locked again,
and I have to --recover it again. Is there a way to make the unlock persistent?

Thanks in advance,

Dirk.

[Håkon Alseth]

Hi,

 

With newer revisions of the nRF52 SoC family, a hardened approtect is added, which requires handling in the firmware to open up the debugger session:

https://infocenter.nordicsemi.com/topic/errata_nRF52832_Rev3/ERR/nRF52832/Rev3/latest/config_832_249.html?cp=5_2_1_0_2_0

 

Is your firmware compiled with newer startup files (MDK)?

 

So I run nrfjprog --recover -f nrf52.
After that, I try to flash my FW, but nrfjprog returns

which version of nrfjprog are you using? Could you share the output of "nrfjprog -v"?

 

Kind regards,

Håkon

[Neum_d]

If I understand the linked explanation correct, I just add NRF_UICR->APPROTECT=0xFF; to my main() ?

I use nrfjprog version 10.12.2:

$ nrfjprog -v
nrfjprog version: 10.12.2 
JLinkARM.dll version: 6.88a

[Håkon Alseth]

Hi,

 

Neum_d said:

If I understand the linked explanation correct, I just add NRF_UICR->APPROTECT=0xFF; to my main() ?

That will lock down the device, so that you'll need to recover each time you reprogram.

Set it to 0x5AUL; to open it up.

 

It is strongly recommended that you update to MDK version 8.40.2 or later:

https://www.nordicsemi.com/Products/Development-tools/nRF-MDK

 

Neum_d said:

I use nrfjprog version 10.12.2:

Could you try to update nrf-command-line-tools to a newer version?

 

Kind regards,

Håkon

[Neum_d]

Thanks. I updated MDK and nrfjprog and now it seems to work. I have to check, if my program does the things still correct.

BTW: The connectivity firmware which comes with nrfutil 6.1.7 seems to use a MDK which is too old...

[Neum_d]

I just saw that updating to MDK 8.53.1 prevents me to use FDS to store data into flash. I assume I have to take additional steps to re-enable it. I opened with NRF_UICR->APPROTECT = APPROTECT_DISABLE_DISABLE_SwDisable, but no success. I assume, I have to change some  other things too, is there a porting guide for the MDKs?