Monitor mode debugging does not work

RE: Monitor mode debugging does not work

Vidar Berg — Wed, 11 Mar 2026 11:11:56 GMT

Thanks for the update. Regarding the error message, this is a limitation imposed bt the on-board debugger FW. I can't comment on whether support for this will be added future, but I have reported this internally to indicate that there is demand for it.

RE: Monitor mode debugging does not work

boz — Wed, 11 Mar 2026 10:13:51 GMT

Thank you, it solved the issue. FYI I just pulled the latest version as the cherry pick caused merge conflicts.

I have another related issue: It works with nRF52840-DK but fails with nRF54L15-DK. I know that the M33 core was previously not supported by monitor mode, but it was added in a later J-Link release in late 2025. However the J-Link OB firmware of the nRF54L15-DK seems to be outdated (July 2025). I checked the firmware update with J-Link tools but it shows up to date. Do you know if there will be an update for the nRF54 OB firmware to support monitor mode?

RE: Monitor mode debugging does not work

Vidar Berg — Tue, 10 Mar 2026 15:42:31 GMT

Hello,

Please try to cherry-pick this commit: https://github.com/zephyrproject-rtos/segger/commit/50892fdbcf2f570e67baa72b8894a66b16946f72. This fix is needed, and was not included in this SDK version.

Best regards,

Vidar