Re-connecting JLinkExe each time after flashing the device

RE: Re-connecting JLinkExe each time after flashing the device

podkiva — Mon, 28 Dec 2020 10:44:57 GMT

Ok, I will look at -AutoConnect option,

Thanks a lot for the help!

RE: Re-connecting JLinkExe each time after flashing the device

Vidar Berg — Mon, 28 Dec 2020 10:04:02 GMT

Yes, it's by design. I'm not aware of any commands to make Jlink commander automatically re-connect, unfortunately, but maybe the -AutoConnect option could make the re-connect process a bit less annoying. Alternatively, as workaround, you may try to downgrade to an older version of nrfjprog during development.

RE: Re-connecting JLinkExe each time after flashing the device

podkiva — Wed, 23 Dec 2020 14:56:18 GMT

Ok, thank you for the explanation!

So, if I understood it correctly, that means that this is by design, and now I have to re-connect J-Link manually like that? So, this behavior is expected?

It is not that I cannot work like that, it just a little annoying.. Maybe there are some way to tell running JLinkExe to reconnect, e.g. by a bash command, such that it automatically re-connects each time I flash th device?

RE: Re-connecting JLinkExe each time after flashing the device

Vidar Berg — Tue, 22 Dec 2020 10:16:09 GMT

Hello,

I looked through the release notes for nrfjprog and found this for the 10.10.0 release:

(nrfjprog.dll) Fixed bug where nrfjprog did not correctly handle debug power. NRFJPROG_close now always ensures that debug power is disabled.

So I suspect this is the problem: nrfjprog turns off the debug power even if Jlink commander is connected and thus breaks the SWD connection to Jlink commander.

Note that leaving the debug interface powered will lead to increased current consumption (~3 mA in idle).

RE: Re-connecting JLinkExe each time after flashing the device

podkiva — Mon, 21 Dec 2020 12:14:21 GMT

Hello!

Yes, I have double checked that right now - I launch the same cmake target that does the flashing after build, and It does not re-build the target each time (only the first time), so the compilation and linking are done only once - but the same effect is observed.

I think that hex-generation, hex-merging, dfu page generation are some of the operations that are repeated on each target run.

Below are the cmake output of the "merged" target (the one that flashes everything - app, softdevice and bootloader)

devzone.nordicsemi.com/.../cmake_5F00_output.txt

P. S.

I forgot the link in the original post to the nRF5-cmake-scripts repository that I use to build my project.

RE: Re-connecting JLinkExe each time after flashing the device

Vidar Berg — Mon, 21 Dec 2020 11:58:57 GMT

Hello,

Are you re-programming the device with the exact same FW? If not, you will likely have to re-connect the debugger in order for j-link to correctly locate the new RTT buffer in RAM (buffer is not linked to a fixed address).

Best regards,

Vidar