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problems when using techGetSpacingRule

Adhil

Hi

1. Im trying to execute the following command:

techGetSpacingRule( tfId "minSpacing" "PC" "CA")

but the it returns nil. is this because the techfile.tf is improperly written, or are there any other reasons

 2. in totally unrelated issue, what is the difference between a master and a supermaster?

 

Adhil.

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  • Andrew Beckett

    Adhil,

    Let me try stating it differently to see if it is clearer for you.

    Every instance in the design is an instantiation of a master. So if you do instId~>master you'll get the cellView object containing a set of shapes, instances, and other objects which represents the thing being instantiated. For normal cells, this is identical to the cellView you'd get when you open the instantiated cellView directly with dbOpenCellViewByType(libName cellName viewName) . If it is a pcell that is instantiated, the master is actually a subMaster. A subMaster is the cellView for the particular variant being instantiated - i.e. the specific combination of parameters that was used on the instance. All instances with the same set of parameters (for the same pcell) will share the same subMaster. However, if you were to use the dbOpenCellViewByType(pcellLibName pcellCellName pcellViewName) you wouldn't get this subMaster because it wouldn't know anything about the specific set of parameters; instead you get the superMaster which is the starting point for the pcell. You can also get from any subMaster to the corresponding superMaster by doing instId~>master~>superMaster. Note that only pcells have superMasters.

    Does that help?

    Andrew.

Reply
  • Andrew Beckett

    Adhil,

    Let me try stating it differently to see if it is clearer for you.

    Every instance in the design is an instantiation of a master. So if you do instId~>master you'll get the cellView object containing a set of shapes, instances, and other objects which represents the thing being instantiated. For normal cells, this is identical to the cellView you'd get when you open the instantiated cellView directly with dbOpenCellViewByType(libName cellName viewName) . If it is a pcell that is instantiated, the master is actually a subMaster. A subMaster is the cellView for the particular variant being instantiated - i.e. the specific combination of parameters that was used on the instance. All instances with the same set of parameters (for the same pcell) will share the same subMaster. However, if you were to use the dbOpenCellViewByType(pcellLibName pcellCellName pcellViewName) you wouldn't get this subMaster because it wouldn't know anything about the specific set of parameters; instead you get the superMaster which is the starting point for the pcell. You can also get from any subMaster to the corresponding superMaster by doing instId~>master~>superMaster. Note that only pcells have superMasters.

    Does that help?

    Andrew.

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