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How to trigger call-back procedure when changing cell-name of existing instance?

Sheppy

Hello,

I am developing a PDK containing various components (p-cells with call-back procedures). The designers using it at this moment, are performing the following steps to create large test-layouts, with lots and lots of nearly identical devices:

  1. Create a layout with many instances of a PMOS transistor, varying parameters like width, length, gate-drian space, gate-source space, etc.
  2. Copy this layout to a new cell
  3. Perform a search-and-replace and changing all cell-names from PMOS to NMOS

In an other PDK, this works, all parameters that need an update (like for instance a parameter called Device Info) are updated, but others, like width and length, remain as is. Thus creating a new layout with virtually no effort. So what clearly happens is that a cell-name change triggers the p-cell to update certain parameters.

When they try to do this with my p-cells, it doesn't work. All parameter names are identical (as is in the other PDK), but after the cell-name change the value of all parameters remain teh same. An example:

The parameter called DeviceInfo contains the following for the PMOS: Standard Low Voltage P-Channel MOS Device
After changing the cell-name, it should be updated to: Standard Low Voltage N-Channel MOS Device

However, this update does not happen.

Now is my question: how do I make my devices behave identical to the other PDK?

How do I trigger the call-back procedure to update, if necessary, the parameters of the p-cell?

With kind regards,

Sjoerd

Parents
  • Andrew Beckett

    Hi Sjoerd,

    Answering your questions in order:

    1. There is the CDF doneProc which gets called once the OK or Apply has been pressed on the edit props (or create instance) form. There's also the formInitProc which is called when the form is initialised. Not sure this would help though. There's no general purpose trigger for the form that works everywhere (given that you have edit props in the schematic and layout which are different, plus the property assistant)
    2. Not as far as I know. There are lots of triggers for various different applications - I'm not sure documenting them all in one place would be very helpful.
    3. Yes. My code is really called abInvokeCdfCallbacks but then I rename it to follow the support naming rules for solutions (I don't always do this, but since I did it for CCSinvokeCdfCallbacks, I've continued to do that). It's possible you may have a different version with slightly different features - the version number in the SCCS info in the header comments shows the version number (the very latest is 1.16). Looking on Cadence online support, it seems that the latest CCSinvokeCdfCallbacks is 1.15 - it's only some relatively  minor enhancement that is missing which I needed to help with a very specific problem I was trying to solve.

    Regards,

    Andrew.

Reply
  • Andrew Beckett

    Hi Sjoerd,

    Answering your questions in order:

    1. There is the CDF doneProc which gets called once the OK or Apply has been pressed on the edit props (or create instance) form. There's also the formInitProc which is called when the form is initialised. Not sure this would help though. There's no general purpose trigger for the form that works everywhere (given that you have edit props in the schematic and layout which are different, plus the property assistant)
    2. Not as far as I know. There are lots of triggers for various different applications - I'm not sure documenting them all in one place would be very helpful.
    3. Yes. My code is really called abInvokeCdfCallbacks but then I rename it to follow the support naming rules for solutions (I don't always do this, but since I did it for CCSinvokeCdfCallbacks, I've continued to do that). It's possible you may have a different version with slightly different features - the version number in the SCCS info in the header comments shows the version number (the very latest is 1.16). Looking on Cadence online support, it seems that the latest CCSinvokeCdfCallbacks is 1.15 - it's only some relatively  minor enhancement that is missing which I needed to help with a very specific problem I was trying to solve.

    Regards,

    Andrew.

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