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Could not find an Cortex-M device in the JTAG chain!

Hi!

I've been using the TM4C123GXL with Keil uVision development environment for a month now. I have always been able to download/run and debug my programs without issues.

Tonight I ran into a problem where the debugger would not pause the program, it would run the entire program then exit. So I ended up messing about the settings.

My messing around caused another problem. Now I cannot even download programs onto the board anymore. I get the following errors when I click Download (F8):

My Stellaris ICDI settings:

What I believe caused this was when I changed the Flash setting in Stellaris to -> Mass Erase (erase entire Flash), then I ran the debugger. After that all programs failed to download.

Any suggestions on resolving not being able to download to board?

Thanks!

  • Also note that the errors appear 3 seconds after pressing Download. It's almost as if it knows the device is there, but it's not able to successfully communicate with it.
  • Fixed the issue. Downloaded LM Flash Programmer. Did several Unlock, and Hardware Reset combinations. That did the trick. Still can't get debugger to work though, will raise a separate question for that.
  • I found solution to both problems:
    1) Debugger suddenly not working. It is due to windows registry, followed this and it works: users.ece.utexas.edu/.../Window8KeilDebuggerFix.htm
    2) Board is not recognized anymore. I downloaded LM Flash Programmer and did a combination of Unlock and Hardware Reset. That did the trick
  • splatapus said:
    ...debugger would not pause the program...ran the entire program...I ended up messing about the settings.

    And those are rather predictable, "Famous Last Words!"   Great danger when one "guesses" re: settings - the "rush" to "fix" leads to far greater delay/frustration/agony...

    It's really neat of you to have "stuck w/your issue" - and resolved via your own efforts.   Great job!

    Not only that - once "fixed" you made the time/effort to "Close the Loop" thus providing a "roadmap" for others - also (likely) compelled to "mess w/settings!"

    IMO more "notable" (prominent) and more repeated "warnings" should appear across most all vendor literature/guides/the works - to save hapless users from this misfortune.

  • cb1_mobile said:
    IMO more "notable" (prominent) and more repeated "warnings" should appear across most all vendor literature/guides/the works - to save hapless users from this misfortune.

     This is what happen when no proper section of forum are available to solve specific problem...

     This is now just a useless social network in some way poorly biased on TIVA, just this thread is focused on but not remain on proper vision nor it can be seen by  new users....

     Maybe super guru "do a search" can work for???

  • One notes - "inmates" not yet - in charge of (this) "asylum."