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    Calibre extracted simulating as schematics

    Hi all,
    I did extraction from calibre xRC and got "calibre" view. When i simulate it by changing the config view of the testbench I get the same simulation results as that of schematics.
    Where I am making the mistake? I did extraction with Assura and its av_extracted shows the desired behaviour, that is it shows the affect of parasitics. What about calibre view?
    Your earliest response will be highly appreciated.

    •   Alt31st December 2009, 05:45

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    Re: Calibre extracted simulating as schematics

    Quote Originally Posted by Usman Hai
    ... Where I am making the mistake? ... What about calibre view?
    May be you didn't add your Calibre extracted netlists to your ADE Model Setup, as I told you here?


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    •   Alt1st January 2010, 17:22

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    Re: Calibre extracted simulating as schematics

    thanks buddy,
    I found the mistake I was making which was very stupid of me then.
    When one changes the config view, he must run the testbench using config view (not with the schematic view). Rest worked great. However, I did not use your spectre method which seems a bit complicated to me. however I did using config view and everything worked as a chime :)

    I have a question for you. I designed an comparator and when I got the extracted from Assura my comparator threshold changed to like 50mV from nominal of the schematic. I knew that I did pretty good job with the layout, so I was not convinced of Assura. Then I did the extraction from Calibre yesterday and my threshold changed to just 5mV (as expected) and I can see all load parasitic capacitance as well. Though I am very happy now but I am not sure why there is such a huge discrepancy between these two. By the way they also show much difference (about 10%)extracting a simple inverter. Any thoughts?



    •   Alt1st January 2010, 17:41

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    Re: Calibre extracted simulating as schematics

    Quote Originally Posted by Usman Hai
    ... Any thoughts?
    The differences must occur from those in the respective extraction rules and from the modeling used therein for the calculation of the parasitics' values. So I guess the old Assura (which emerged from the still older Diva) extraction rules and their used models have been prepared much earlier than the Calibre extraction and model rules, so, again, I guess the Calibre extraction is more exact than the Assura one.

    To find out if this is true, it would be necessary to study and compare the 2 rules set files, and this IMHO would be a rather tedious job!

    Of course one could plead wishful thinking , but I'd better trust the newer stuff.

    Thank you for having pressed the helped me button and good luck for 2010 and your chip!



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