Mass Erase SWD sequence for KL25Z

[quevedo]

Hello,

I have had some problems with FRDM-KL25Z boards becoming unresponsive in the lab course i am teaching at. I still have to find out what caused 3 boards to stop responding to debugger. OpenSDA is recognized but is unable to take control of target processor.

I have seen a way to unlock these boards on MCUonEclipse blog, but it demands having an external programmer, and I think I could create a more effecient solution, loading a custom OpenSDA app in the K20 processor on the board and installing a jumper for KL25 power source. For this purpose, I need to learn a way to halt the processor through SWD interface, as quick as possible, and also a way to mass erase the target processor through SWD commands.

Surely, I may read all SWD manuals and also KL25 reference manual, and find out for myself the SWD commands I need to issue, but I wonder if someone who is more familiar with the interface could provide a sequence of SWD commands to halt KL25 quickly, right after it leaves reset state (which I will also control through the custom OpenSDA app), and also a sequence to mass erase its FLASH.

I intend to keep the community aware of my progress, and I also intend to publish the final source code for the OpenSDA custom app if I am succeeded.

Thanks in advance,

Antonio

[Jorge_Gonzalez · Accepted solution]

Hello Antonio:

Have you checked the next post in this community by pgo?

Utility for erasing dificult FRDM Kinetis boards

I have not tried that program, but I tend to think it works.

Regards!

/Jorge Gonzalez

[quevedo]

Perfect! That worked nicely! I just have one thing to add about pgo's app: If I power on the board without the jumper for powering the target processor, OpenSDA enters Bootloader mode, even if reset button is not pressed. Thus, when running the app one needs to keep the jumper on while connecting the board to USB, and only after that, power on target can be cycled off and on. But then it takes control of the target and mass erases it at first trial.

[quevedo]

I think it may just be what I need. It demands removing 0-Ohm resistors from the board, to control target power, as I had just imagined. I will give it a try next week (I will be away from University, and from my workshop, till Tuesday), and then I will post the results. Depending on what happens, I will contact the creator to request the source code, and try to improve it.