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  3. Plotting pole/zero results

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Plotting pole/zero results

Grover
Grover over 15 years ago

I often use the pole/zero analysis in Virtuoso GXL (6.1.3), and it works great, but the way to plot the poles and zeros is quite inconvenient. After each simulation, I have to click somewhere in the Results tab, select "Direct plot -> Main form", click "pz", set options, and click "Plot" before the results appear.

Obviously, it's quite annoying to do all this after each simulation run, while the normal AC analysis just pops right up. Is there a way to make the pole/zero plot appear automatically?

(perhaps equally annoying, is that Virtuoso also always opens another copy of my schematic. I usually work with ADE in one window and the schematic in another, but when I click "Main form", it opens another copy of the schematic in a new tab in ADE. Is there a way to stop this? This also happens when I choose "Print", e.g. for a pole/zero list or detailed operating points.)

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  • Andrew Beckett
    Andrew Beckett over 15 years ago

    Use the "add to outputs" button on the direct plot form - this will add it into your ADE outputs, and then you can choose for that to be plotted automatically after each simulation.

    Are you using ADE XL? Or ADE L - your post wasn't that clear.

    Regards,

    Andrew.

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  • Grover
    Grover over 15 years ago

    I'm using ADE XL. But the problem is that this "add to outputs" button doesn't exist for the pole/zero plot. It's there when you choose "ac", but not when you choose "pz".

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  • Andrew Beckett
    Andrew Beckett over 15 years ago

    Well, I'd never noticed that before...

    If you create an output expression which is:

    { pzPlot() 0}

    or:

    {pzPlot(?plot 'zeros ?freqfilter 1e12 ?realfilter 0.001) 0}

    The ?plot argument can be 'zeros, 'poles or 'polesZeros (default is 'polesZeros). Note that pzPlot is documented, so you can find out more details in the documentation.

    Surrounding in curly parentheses is because the function returns t, and an expression needs to return a number - so it has been made to return 0 in this case.

    I found there is a CCR, 83212, asking for Add to Outputs to be added for pz analysis, and also CCR 129416 is relevant here. If you want this, please contact Cadence Customer Support and  request that a duplicate CCR is filed to increase the demand for this enhancement.

    Regards,

    Andrew.

     

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  • Grover
    Grover over 15 years ago

    Wow, thanks! This makes my life a lot easier :-)

    But still, do you have a solution for the second issue I mentioned? Now that I can automatically plot poles and zeros this is less important, but it still happens when I want to check e.g. the detailed operating point. Is it because I have one window with ADE and another with Schematic, and they are not aware of each other?

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  • Andrew Beckett
    Andrew Beckett over 15 years ago

    What subversion are you using? I was just checking with 6.1.3.500.17, and if I have the schematic open already - either in another window or another tab, it automatically switches to it when I use direct plot.

    If the schematic is not already open, it opens it in a new tab and switches to it, when I use direct plot.

    So I've not been able to reproduce it - maybe I've not go the scenario the same as you?

    Regards,

    Andrew.

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  • Grover
    Grover over 15 years ago

    I'm using 6.1.3.500.13. In detail, this is what I do:

    1. Start Cadence and open the Library Manager
    2. Double-click the schematic view of my circuit (and drag the window to monitor 2), then descend into the part I'm interested in
    3. Double-click the adexl view of my circuit (and drag the window to monitor 1)
    4. Run a simulation
    5. Right-click the results, and choose "Direct plot -> Main form" (or "Print -> DC Operating point")

    The first time I do step 5, the Schematic window (on monitor 2) returns right to the top of the stack, so I have to descend my way back down to the component I want to measure. Everything else is just fine.

    Then I run the simulation again, and do step 5 again. Now the Schematic window stays the way it is, and the ADE XL window (on monitor 1) opens a second tab with the schematic (at top level). When I keep repeating steps 4 and 5, it just switches to this schematic tab each time.

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  • Andrew Beckett
    Andrew Beckett over 15 years ago

    OK, I see - I've reproduced that. I found existing CCR 597896 which talks about this too - I appended your description to it.

    It appears to be proposed to be fixed in IC615.

    Regards,

    Andrew.

     

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