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Modifying Pcells from PDK

nosaj

Hi all,

 I'm looking for ways to slightly modify Pcells (transistors, res, etc) from a PDK. 

I've come across two db functions :

DumpPcDefinePcell and WriteSkill

The idea is to dump the skill code from the Pcell, modify the code and recompile it. But the files that these fuctions return are not exactly easy to read. And some even contains callbacks from the PDK that most likely is encrypted.

example :

dbD_0xf1156512 = dbCreateRect(dbD_0xf1156612 list(236 -1)
        list(-1.100000e-01:0.000000e+00 1.500000e-01:1.200000e-01))
dbD_0xf1156513 = dbCreateRect(dbD_0xf1156612 list(75 -1)
        list(-2.700000e-01:-1.600000e-01 3.100000e-01:2.800000e-01))
dbD_0xf1156516 = dbCreateRect(dbD_0xf1156612 list(26 -1)
        list(-2.400000e-01:-2.000000e-01 2.800000e-01:3.200000e-01))
dbD_0xf1156515 = dbCreateRect(dbD_0xf1156612 list(26 -1)
        list(-2.900000e-01:-2.000000e-01 -2.400000e-01:3.200000e-01))

Is this the actual code the foundry used to compile the Pcell or is it something that's Virtuoso spills out based on the compiled Pcell?

How should one go about modifying the Pcell layout from these codes? Without knowing how these code correspond to the layout, it's nearly impossible.  Can it be done in other ways? 

Any ideas?

 

 

 

 

 

 

Parents

  • Thanks for the reply.

    There were some request to see if the Pcell can be modified.  For example, creating multpile contacts, etc.  That's why I try to find out what can be done.  I haven't contacted the foundary yet since I'm just exploring the idea.

    As for the yank and paste then flatten approach,  wouldn't the create instance form disappear for the new cell?  How can I preserve the form?

     

     

Reply

  • Thanks for the reply.

    There were some request to see if the Pcell can be modified.  For example, creating multpile contacts, etc.  That's why I try to find out what can be done.  I haven't contacted the foundary yet since I'm just exploring the idea.

    As for the yank and paste then flatten approach,  wouldn't the create instance form disappear for the new cell?  How can I preserve the form?

     

     

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