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New Contributor I

preserve attribute doesn't seem to work for me

Dear Support,

I'm having hard time working with SignalTap, can't find signals I'm interested easily.


attribute preserve: boolean;
attribute preserve of Signal1 : signal is true;
attribute preserve of Siganl2 : signal is true;


does not help me to find any with filter = SignalTap:pre-synthesis or Post-Fitting. Filter = "Design Entry (all names)" seems give better search results, but still not complete covering all the signals I set to preserve. I'm using the default synthesizer.

And I learned form Altera SignalTap online training, saying the only valid filters to use are: SignalTap:pre-synthesis or  Post-Fitting.

Please comment

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If a signal does not show up in the Signal Tap pre-synthesis or post-fitting filter, there's a reason why the signal cannot be tapped, such as an output signal to a pin (no route back into the device) or a signal on a carry chain route (no route out of the carry chain).  What are the signal(s) you are trying to tap?

If you can provide code, maybe the forum can help you add code to bring the signal out in a way that it can be tapped. 


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