Forum Discussion

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

Signal Tap

Hi,

I have some problems with the Signal Tap Logic Analyzer.

Sometimes it works pretty nice and I can observe the selected signals. But sometimes it smashes my design completely, if only I change some nodes.

Means: I run the design on the board, using the signal tap logic analyzer, have no problems at all. Then I decide to observe some other signals, change the nodes in the

signal tap setup window, recompile , and my design behaves completely strange.

I get no warnings (beside the 1400 standard warnings :-/ ) or errors during compilation.

I'm using Quartus II Version 6 and a niosII Cyclone II Development Board

I hope, that somebody can give me a hint, because its very annoying to compile 1 hour for nothing...

1 Reply

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

    Hi Maria

    First, I'm sorry for my bad english...

    - What happens, if you re-change the nodes back to the state before?

    Very IMPORTANT:

    - Are you shure that your design is really synchronous?

    Some severe asynch path in your design will sometimes produce exactly this situation: every time you re-compile your design (without any change !) the result is not predictable. This is not an failure of Quartus. Your design in FPGA must be as synchronously as possible.

    I had that problem while re-engineering an completely asynch APPLE II into synch FPGA. Now I have more grayed hair after finishing that project succesfully... http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/rolleyes.gif

    Jens