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Default param values not saved in OA cell property.

SrBraj

When I place a pcell and do not change the W parameter (default is used) the value is not saved in the OA cell property.

When I change the default value of the super master now, the old pcell will get the new default value automatically because there is nothing saved inside the OA cell for this parameter.

Do you have any Idea, that how we can save the default values in the OA cell properties so that this value doesn't get updated if the default values are updated in the new PDKs

  • Andrew Beckett

    If you set the parameter in the CDF for that cell to have storeDefault=yes, then it will put the property  on the instance even if it is the same value as the CDF default.

    Note that in general it's wise to have the CDF and PCell defaults the same (and if you don't, you really must set storeDefault=yes otherwise you'll exhibit odd behaviour because the form would show the CDF default, but the instance's behaviour would reflect the Pcell's default).

    Andrew.

  • SrBraj
    in reply to Andrew Beckett

    Hi Andrew

    Thanks for your quick reply as always.

    I want to do the following in my pcells:

    I. initially for a parameter w of p-cell A, default value was set to 5u in CDF

    ii. I created a layout design "demo" and placed the pcell on to it. Save and close the design. 

    iii. Now I have changed the default value of parameter w of p-cell A to 7u in CDF.

    iv. If I open layout design "demo", then it should not update the value of parameter w to 7u. Should keep the value to 5u only.

  • Andrew Beckett
    in reply to SrBraj

    Provided that storeDefault=yes has been set for w in the CDF before you place the instance in step ii above, it will do as you expect. 

    Andrew

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