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TM4C1237E6PM: After working for weeks, LM Flash Programmer won't work because of "USB Device Not Recognized" error, TIVA device seems to be bricked.

Part Number: TM4C1237E6PM

I have been using LM Flash Programmer for weeks to program the TM4C device on our custom board.  I am using the USB DFU configuration.  I made yet another change to the code, entered the dfu command in my TeraTerm window, and then programmed the device.  At this point I lost all connection to the device.  Nothing happened in TeraTerm when I hit enter.  I closed down TeraTerm and opened it up again, and there was no TivaWare COM port listed.  I unplugged the USB cable and plugged it back into my laptop, and after several seconds I saw a pop-up telling me "USB Device Not Recognized".  I think the TM4C is bricked.  How can I unbrick it?

  • Hello Chuck,

    What interface are you connecting to the device with? Are you re-using a LaunchPad ICDI? JTAG? If JTAG, which debugger?

    Edit: I should clarify what I am trying to understand here - is there some sort of JTAG interface we can tap into in order to reset the device?

  • Greetings,

    Vendor agent is correct w/his assessment - yet there (may) be a, "Faster & Easier Way!"

    The electronic trade press has recently noted a great increase in, "Pirated USB Cables."   Might yours be one?   Even if "having past worked" - impedance mismatches are brutal AND connections between wire & cable receptacles are proven to "Weaken & suddenly fail."

    Worth a quick Cable Swap - young (outsider) staff here advises...