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Force db update/refresh regarding connectivity and pcell parameters

frankliu

Problem statement:

1. In layout XL create a (metal) rectangle and add a net name to it.

2. In skill add a (same layer) rectangle that abuts or overlaps this rectangle

3. Query the associated nets with this new rectangle in skill

   Result: its net name does not get updated

   Expected result : the net name associated with 1.



Note:

If instead of 2. you manually create a rectangle from the layout editor, then the query in 3., works as intended.

If I put a breakpoint between 2 and 3 then 3. works

If I add a dbSave between 2 and 3 then 3. works



I would like to avoid using dbSave, since this is too heavy handed and slows down my script.  I would like the connectivity information to be updated at the end of 2.  Please let me know if there is a way of updating this information.



Note:

In the title I also mention pcell parameters, this also happens with pcells, I know that in some cases you have to call the callback function associated with a parameter in the pcell, and I have, but a similar situation happens.  For example in a transistor pcell, when I change the number of fingers, and then query for the geometry of the poly, I don't get an updated number, and as in the connectivity example above, if I insert a breakpoint or perform a dbSave then the information gets updated.  Clearly something must be called within dbSave or when restarting from a breakpoint to update the connectivity / cell parameters.



Sorry if this is not clear, please let me know if you need further details.

Parents

  • For the VLS XL connectivity extraction (the first problem), the issue is that the connectivity extractor normally gets called as part of the interactive update loop. You may need to call the extractor (lceExtract) yourself?

    For the pcell change, this should happen directly - if you change the parameters of a pcell, then the master should get updated to a new subMaster. I'm assuming you are not doing something like this:

    inst=...
    master=inst~>master
    inst~>fingers=...

    and then look at master? That won't work, because if a pcell parameter changes (assuming that fingers is a pcell parameter), the instance will then point at a new subMaster of the pcell and you'd still be looking at the original subMaster. If you re-access inst~>master you should see the updated shapes...

    There's nothing special you need to do to do a database refresh in this case.

    Regards,

    Andrew.

Reply

  • For the VLS XL connectivity extraction (the first problem), the issue is that the connectivity extractor normally gets called as part of the interactive update loop. You may need to call the extractor (lceExtract) yourself?

    For the pcell change, this should happen directly - if you change the parameters of a pcell, then the master should get updated to a new subMaster. I'm assuming you are not doing something like this:

    inst=...
    master=inst~>master
    inst~>fingers=...

    and then look at master? That won't work, because if a pcell parameter changes (assuming that fingers is a pcell parameter), the instance will then point at a new subMaster of the pcell and you'd still be looking at the original subMaster. If you re-access inst~>master you should see the updated shapes...

    There's nothing special you need to do to do a database refresh in this case.

    Regards,

    Andrew.

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