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TM4C123BH6ZRB: TM4C123BH6ZRB (TIVA): Recovering a locked Microcontroller => JTAG-Interface does not response

Part Number: TM4C123BH6ZRB

Hi,

I recovered a locked TIVA microcontroller via debug port unlock sequence (by I-Jet Trace in IAR Workbench for ARM)

(s. Manual p. 199: Performing a total of ten JTAG-to_SWD and SWD-to-JTAG swith sequences while holding the microcontroller in reset to restore BOOTCFG-Register).

After PowerON-Reset flashing via JTAG or SWD is no longer possible!!!

So could you please tell me if JTAG / SWD communication must be possible after unlocking sequence?

Or is ROM-bootloader the only way for flashing?

Thanks in advance,

Tobi

  • HI,

    Do you remember what did you do prior to the device being locked?

    If you have successfully gone through the unlock sequence then the JTAG communication should be possible. The question is how do you know you have unlocked the device successfully?

    Do you have other debug probe such as XDS100, XDS110 or XDS200? If you have one, then you can use the Uniflash to unlock the device.

    Do you have a TM4C123 or TM4C129 launchpad? If you have one, then you can use the the launchpad which contains the ICDI debug probe to debug your board and you can use the LM Flash Programmer to unlock the device.

    See section 5.3 and 4.6 in this app note for details.
    www.ti.com/.../spma075.pdf
  • Hi Tobi,
    I have not heard back from you. I assume you are able to resolve the issue. I will close the thread for now. If you have new questions you can open a new thread or reply back to this thread with some comments if the issue persists.