How to get a J-link debugger running on an FRDM-KL03Z board

[filipdossche]

Hi,

I can't get my Segger J-link Ultra to work on my FRDM- KL03Z board.

I have set up everything as described in this thread: Low power demo application on FRDM-KL03Z board

It works to a degree: the link to the GDB works, the J-link is detected and set up.

It is just the connection to the board which fails (see attached log file).

I am absolutely sure that the J-link is properly connected ( I have checked it often enough by now) which is confirmed by the fact that the supply voltage is correctly measured.

I can't believe there is something faulty on the FRDM board or the Segger J-link so I suspect it is just a matter of the software/hardware setup.

Note: the FRDM board is still powered by the USB port but from a software point of view it is inactive so I would suspect it does not influence the operation of the SWD_DIO, SWD_CLK and RST pins but I may be wrong about that.

Any help/suggestion much appreciated.

Original Attachment has been moved to: J-Link_debugger.log.zip

[filipdossche · Accepted solution]

Hi all,

For some really odd reason all of a sudden it came to life.

Instead of using the FRDM-KL03Z board I used another board with the same KL03Z chip, in essence a prototype of what will be our final project hardware.

It has the advantage that there is no second processor on the board to handle the OPEN-SDA so it could not interfere.

That did not work either for several hours, including using the "J-Link Commander" to get direct contact with the KL03Z on the prototype board.

Finally I wanted to check if there was any SWD_CLK signal and used an oscilloscope for that.

To be absolutely sure an SWD_CLK signal would be generated I restarted the "J-Link commander" software because it tries all possible connection methods, including the SWD interface.

Do not ask me why but as soon as I did that I got contact with the target device and ever since then debugging etc... now works perfectly with or without a scope connected.

It defies any sort of logical explanation but that is what happened.