• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 96 subscribers
  • Views 143 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

AM3359 doesn't respond to hardware reset

Qi Wang2
Prodigy 110 points

Hey,

I have a design using AM3359ZCZ and the problem is that I found 2 boards (out of twelve I have made) have the following same booting issue:

After pressing the reset bottom, the console( via serial port) immediately shows "U-Boot SPL 2012.10-00010-g847bb01 (Oct 25 2012 -11:41:49)"

and then it hangs, but after a while it continues to boot normally and load the kernel, the period is uncertain and can range from several seconds to several minutes.

And something more weird is when CPU hangs in that case, it doesn't even respond to the hardware reset.

Does anyone know what happen during that period, why the hardware reset doesn't work?

PS:

The design is based on beagle bone, it has 256M ram and boots from uSD card.

Thanks!

Qi

  • 0
    Expert 1530 points

    There, on Sitara chip are more than one signals you might call a Reset. Also since the story is somehow hardware related, there are voltage levels, and transition times.

    If I were you I'd look at every Reset (PORZ, NRESET, NTRST, ..) using oscilloscope. Most likely the solution is there.

    As about our forum, I'd suggest posting here a PORZ-related fragment of your schematic.

    Cheers,

  • 0 in reply to sviss
    Prodigy 110 points

    Hi Sviss,

    I measured PORZ, NTRST, they are both at normal level.

    The more detailed description of my problem is:

    When the CPU hangs as I mentioned above, then I push the reset button, which will pull NRESET_INOUT low.  The NRESET_INOUT will transit from high to low and keep low for long time, that's why it makes me feel the CPU doesn't respond to the reset.

    Thanks!

    Qi