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aligning eye diagrams across corners

KurtKimber1

I'm simulating a receiver across corners.  Each corner has a different amount of delay.  When I plot a node "across corners" and then generate the resulting eye diagram, all these different delays from the different corners result in the composite eye being much narrower than is the case if the corner delays could be nulled.  What would be the simplest/quickest way I could shift the different corners to into time alignment?  If that can be done, then I can use eyeAppeture to generated stats on the eye at all the nodes along the receive path.  This doesn't have to be automated; it would be fine if I could manually add a shift to each corner.  But once this is done, I would like to be able to save this result to be used by eyeAppeture on different nodes in Assembler.  Thanks in advance.

Parents
  • Marc Heise

    Hi Kurt,

    could you try  the "lshift"  function from the calculator?  I've not tested it and have no idea if the eye diagramm function will work with the result. Maybe you also need to
    use a "clip" afterwards to make sure all the waves  have the same starting point.  But I could be totally wrong here.

    Regards,

    Marc

  • KurtKimber1
    in reply to Marc Heise

    I was able to get Marc's suggestion to work (only used lshift/rshift, didn't have to clip); eyeAppeture now generates good stats on the composite eye diagram.

    I now have three output expressions, one for each fast, typ, slow corner that I have to manually plot to generate the delay-nulled set of waveforms I want.  Is there some way to instruct Explorer/Assembler to automatically plot this particular mix of output expressions and corner runs?  I.e. the fast output expression I used for plotting the fast corner, the typ output expression I used for plotting the typ corner, the slow output expression I used for plotting the slow corner.  Thanks

Reply
  • KurtKimber1
    in reply to Marc Heise

    I was able to get Marc's suggestion to work (only used lshift/rshift, didn't have to clip); eyeAppeture now generates good stats on the composite eye diagram.

    I now have three output expressions, one for each fast, typ, slow corner that I have to manually plot to generate the delay-nulled set of waveforms I want.  Is there some way to instruct Explorer/Assembler to automatically plot this particular mix of output expressions and corner runs?  I.e. the fast output expression I used for plotting the fast corner, the typ output expression I used for plotting the typ corner, the slow output expression I used for plotting the slow corner.  Thanks

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  • Marc Heise
    in reply to KurtKimber1

    I not completely understand the question. What manual task you need to automate?   If you can find a measurement for the delay you can use it to feed it to the rshift/lshift.

  • KurtKimber1
    in reply to Marc Heise

    Assume the correct values for rshift/lshift are known.  Is there some way to have Assembler automatically plot the correct delay-adjusted waveforms from each corner in order to generate a composite eye diagram representing all the corners?

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