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physOnly - physical only argument for terminal treation

Adrian Nistor

Hello,

It's not very clear to me what is the purpose of physical only argumen. 

If I create a PIN with Create - Pin I have the check box "Physical Only". Also in dbCreateTerminal the last optional parameter is b_physOnly. In the documentation it sais that for creatng strong connected terminales, the second and the other terminales should by physical only. But what if they are not ? 

So: What is the purpose of this option?

What test case should I try tu understend the differences of using physOnly = t and physOnly = nil ?

Thank you,

Best Regards,

Adrian

  • Austin CAD Guy

     I do not know if any Virtuoso tools use this attribute but it is used to designate terminals that are not represented in the logical database. For a mustConnect set of pin shapes, some of them are attached to a terminal that has the same name in the layout as the symbol. Others pin shapes which are not connected internally in the layout but are of the same internal net have to be created as pin shapes on different nets with different terminals connected to the logical terminal using dbSetTermMustJoin. These terminals do not have an identically named logical terminal in the symbol so they are "physOnly". I've used this attribute when trying when searching the pins to find the logical terminal name. VXL may use this as well.

     Ted

  • Adrian Nistor

    Hi Ted, thanks for the reply;

    How could I verify for a pcell which are the logical terminals and which are the physical terminals ? In otherwords, how could I test what you said ? :) It would be usefull to find the difference between physical only terminals and normal terminals in  a testcase because this way I woud have a real example and I could understend better.

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