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Altera_Forum's avatar
Altera_Forum
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15 years ago

signaltap question trigger

I am trying to tap into a module. The module works fine except sometimes randomly it stops working. I need to tap the last snapshot of the signals and acquire only the values when it hung. All the trigger points give me the first state and are of no use. Is there a way in signaltap to store the state in the temporary memory and then when it hangs I can read the last state on my screen instead of getting the first trigger values.

Thanks

3 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    15 years ago

    Do you have a signal that changes just before the hang and that you can use as a trigger? If not what I would suggest is to create an additional signal that detects the hang and goes from 0 to 1 when it is detected. You can use this one as a trigger to see what happened before.

  • Altera_Forum's avatar
    Altera_Forum
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    15 years ago

    I do not have a signal which tells me that the system is hung. It happens on the software side on the host. I want to capture the signals when the host tells me it has hung because after that there is not going to be a change on signals so I can see the state. So I need to tap them out on the computer screen in the analyzer at that time .Is there any manual way of telling the analyzer when to display the signals and not at every point of the trigger.

    During the correct transaction it can store the values internally which are then overwritten by the next cycle till there is a problem. When the problem occurs there will not be any more triggers and then I can tap the stored values out on the analyzer to view them. Is there some mechanism for such a process in signaltap?
  • Altera_Forum's avatar
    Altera_Forum
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    15 years ago

    I'm not sure I understand what you want to do, you seem to describe two different needs in your two paragraphs.

    If the signals don't change at all after the hang up, you can just disable all the triggers in signaltap and do a single run. Then you'll see immediately the state of all your signals.

    I don't remember if it is possible to capture the last time a trigger is active instead of the first one. You can try the "autorun analysis" function to capture data until you stop it, but I don't remember if it disables the triggers or not.