nrf5340 keeping flash sectors between flash burns

RE: nrf5340 keeping flash sectors between flash burns

Raoul — Sun, 26 Feb 2023 22:45:39 GMT

Hi Tamas,

I wasn't aware of the difference in flashing times between JLinkExe and nrfjprog! Thanks for sharing, appreciated.

Best regards,

Raoul

RE: nrf5340 keeping flash sectors between flash burns

Tamas Selmeci — Wed, 22 Feb 2023 09:55:52 GMT

Hello Raoul!

I've tried both versions:

Segger JLinkExe version 7.86 can really burn the flash, so the sensitive last two flash sectors can be preserved;
nrfjprog with --sectorerase instead of --chiperase also does the trick, another useful solution;

I'm just remarking that:

nrfjprog with --sectorerase is much slower than with --chiperase;
JLinkExe burns the new FW image much faster than nrfjprog (in my case 8s vs. 12s);

Thanks for the help!

RE: nrf5340 keeping flash sectors between flash burns

Raoul — Tue, 21 Feb 2023 15:36:54 GMT

Hi Tamas,

The --sectorerase option should do what you need. It will only erase the flash ranges targeted by the hex file you are programming:

nrfjprog.exe --program merged.hex --sectorerase

Just pay attention to the following:

1. Make sure your persistent data is stored within 4kb pages that are not targeted by the hex file you're flashing. Erasing happens on a page by page basis.

2. Ensure that you're not enabling APProtect during development as it will lock down the device and require a "recover", erasing the entire flash.

This case discusses a similar use case to your, you might find it useful: Please clarify/explain use of --sectorerase with nrfjprog

If you want to use jlink.exe / J-Link Commander, it seems that it defaults to "sectorerase" behavior, but I see there have been issues with this in previous versions: https://forum.segger.com/index.php/Thread/8706-SOLVED-Use-J-Link-commander-to-flash-a-file-to-area-that-is-not-erased/

Best regards,

Raoul