Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

Output pins stuck at VCC or Ground. No idea why

I have found many posts about this but havent found a solution. Both my friend and I are having issues with this. I'll post my code on pastebin as it is 500 lines long, most of it is repeated, so it really isn't too complex.

When I compile the block diagram it says that every output pin is stuck at vcc or ground and the every input pin doesnt drive logic.

I also get these 2 errors:

-Warning: Timing Analysis does not support the analysis of latches as synchronous elements for the currently selected device family

-Warning: No paths found for timing analysis

***MAKE SURE TO REMOVE THE SPACES AND * BETWEEN COM IN THE URL***

Here's the pastebin code. pastebin. * c * o * m/YtPg8H5j

Here's a picture of the schematic: i27.photobucket. * c * o * m/albums/c198/swargy/Random/design.png?t=1292047094

Any help would be greatly appreciated. Thanks!

3 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    Sometimes,output pins are assigned to '0' or '1',so it reports...stucked at VCC or GND. If the program need,just ignore them.

    QuartusII program need to use each input vectors to kill the related input drive warnings.

    above is just my thinkings,pls be refered.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    The warnings are given, because your state machine is apparently stuck in initial state s0. The else clause never comes true, because if count = '1' and elsif count = '0' cover all posible cases. Consider the intended behaviour and correct the code.

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    Ah! I can't believe I didn't see that! We were thinking it had to do with count as initially we never even set count back to 1! Thanks!

    The whole reason for that else is because we wanted to push a button repeatedly and have it register the push every time. If I throw it inside the if (clock'event and clock = '1') statement then those button clicks are only registered once a second and I believe the button has to be down at exactly that tick.

    Am I wrong about this?

    If not then how do I got about allowing the buttons to be clicked as fast as possible but the output to be displayed for 1 second as I dont want the output to flash on the 7-segment and then just go away.