Unlock kinetis on SKEAZN32XXX2

[michael11]

Greetings,

I am currently working with SKEAZN32XXX2 on a custom board. The SKEAZN32XXX2 is programmed through connecting a SEGGER J-Link Arm programmer and then reading a binary file to it (usually through SEGGER J-Flash Lite V6.44a).

I have been able to both program it and erase without any problems until recently. 

The problem first occurred when I pressed "Erase Chip" in J-Flash Lite followed by pressing it "Erase Chip" again.

If I use Jlink Commander I am able to connect to the processor (through SWD) and I am able to read out the whole data flash from the processor (which only consists of 0xFF at the moment). 

Furthermore, I have tried to use the command Unlock Kinetis (since the MCU is of that family). The response to that is "Unlocking device..Timeout while unlocking device."

Then I have tried to program the device again with the result of "Communication timed out: Requested 4 bytes, received 0 bytes!

Target voltage too low (1 Volt is required, Measured: 0.0 Volt).

Unspecified error -1".See attached screenshot for exact output.

I have read some related posts on the issue (for different MCUs):

https://community.nxp.com/thread/300407

https://community.nxp.com/thread/447276

and some from the J-Link forum:

https://forum.segger.com/index.php/Thread/1074-Error-Supply-voltage-too-low-with-J-Link-and-BeagleBo...

https://forum.segger.com/index.php/Thread/2390-JLink-on-unsecure-and-erase-Kinetis-FLASH/?postID=802...

With that being said, my two main questions are why exactly does this problem occur and is there a way to unlock/recover the SKEAZN32XXX2 chip again from this mode?

Best regards,

Michael.

[michael11]

Hi Kerry,

I tried what you suggested many times. My concerns were that I was able to connect to the MCU halt it and reset it.

I moved on tried different drivers for the JLink adapter with the same result. Then switched to another computer to see if the problem was still there, which to my surprise it was not!

This issue turned out to be a problem with the USB port that I had on my USB hub connected to my PC. I switch to another USB port on my USB hub and I am now able to program and erase the MCU again.

Thank you for your fast answer and advice though!

Best regards,

Michael.

[kerryzhou]

Hi Michael,

   Thanks a lot for your test result sharing.

   So, it turns out the problem is related to the USB port problem.

   If you still have question in the future, welcome to create the new case.

   About this case, if you don't have problems, please help to mark the correct answer, just to close this case, thank you!

Have a great day,
Kerry

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[kerryzhou]

Hi Michael.,

    Please try to power off the board, and power on the board again, then use the JLINK commander to connect your board again, can you find the ARM core or not?

   If you still can find the ARM core, you can use loadfile xxx.bin commander.

  Or you can use the IDE to download the code with the jlink.

  If you still have question about it, please kindly let me know.
Have a great day,
Kerry

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- If this post answers your question, please click the "Mark Correct" button. Thank you!

- We are following threads for 7 weeks after the last post, later replies are ignored
Please open a new thread and refer to the closed one, if you have a related question at a later point in time.
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[michael11]

This answer did not answer my question but it was a piece of advice that led me to the solution to the issue.

Best regards,

Michael.