topic Re: KW41Z bricked (secured + flash protection) in Kinetis Microcontrollers

KW41Z bricked (secured + flash protection)

tommot — Wed, 28 Feb 2018 08:27:12 GMT

Hy everyone!

I have a question concerning recovery of a bricked KW41Z (on a Rigado R41Z Evaluation Board).

When testing Segger Embedded Studio I didn't check if the area for setting flash secure and mass erase bits was exluded from allowed memory ranges (trusting the default settings).

J-Link can now access the device but it cannot erase or unlock it.

"Readout protection is set and mass erase is disabled. J-Link cannot unprotect the device."

After some research, finding tips for unlocking other Kinetis MCUs I currently think that there is no way of recovering the device.

But I wasn't able to find something KW41Z specific. So my question: Is it really dead? :smileywink:

Thank you and best regards

Thomas

Re: KW41Z bricked (secured + flash protection)

jorge_a_vazquez — Tue, 06 Mar 2018 14:38:35 GMT

Hi Thomas Bigler

The only method to recover a secured device is to launch a mass erase command. Unfortunately, if you Jlink debugger mas your device as protected and mass erase disable. then yes, there is no way to recover your device. I would like to recommend you next link:

How (not) to Secure my Microcontroller | MCU on Eclipse

Best regards

Jorge Alcala

Re: KW41Z bricked (secured + flash protection)

tommot — Tue, 06 Mar 2018 14:52:57 GMT

Thanks for your answer and the link, I was actually expecting that.

So this microcontroller will forever keep its 5 line hello world program :smileywink:

I already adapted the linker script (default one from Segger Embedded Studio is incorrect) so that this will not happen again.

Best Regards

Thomas