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SSN warning and ugly waveform at AP SI 15.7

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The warning message is "Only one DC plane was found, cann't mesh ground."
Sometimes the warning message is "No voltage source pin is found for Ground Bounce"

The waveform is attched.

What is the problem?

But at "comprehensive" simulation, I could see the SSN at same environment.

Please let me know.


Originally posted in cdnusers.org by imsong
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    You've succeeded in getting noisy power and ground busses, so it seems the question/warnings are related to the quality of the waveforms. WARNINGs draw your attention to something that may not be setup quite right, even though you still achieved some result. In your case, you may need to "Identify DC Nets" so that the tool knows which planes to mesh. For example, you may need to apply 0V to your ground planes.

    Either way, the non-ideal power is modifying your signal performance so it would be interesting/valuable to compare how much change you see as compared with using ideal power. And if the dark blue waveform is your receiver, I'd be concerned about its Vswing and the loss incurred from the driver (which I'm guessing is brown?).

    Hope that helps. It's a bit difficult to understand the question. Also, it's helpful to vary the colors in your waveforms.


    Originally posted in cdnusers.org by Donald Telian
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  • archive

    You've succeeded in getting noisy power and ground busses, so it seems the question/warnings are related to the quality of the waveforms. WARNINGs draw your attention to something that may not be setup quite right, even though you still achieved some result. In your case, you may need to "Identify DC Nets" so that the tool knows which planes to mesh. For example, you may need to apply 0V to your ground planes.

    Either way, the non-ideal power is modifying your signal performance so it would be interesting/valuable to compare how much change you see as compared with using ideal power. And if the dark blue waveform is your receiver, I'd be concerned about its Vswing and the loss incurred from the driver (which I'm guessing is brown?).

    Hope that helps. It's a bit difficult to understand the question. Also, it's helpful to vary the colors in your waveforms.


    Originally posted in cdnusers.org by Donald Telian
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