property bags and pcells

I would like to know how property bags work with pcells. I have
tsmc25rf pdk and trying to find out how the pcell code is called. I
find property bags for each device but I dont understand how the pcell
code is called from the property bag. Can anyone explain how this is
setup.

thanks,
Sriram

 

pcell code is not called from property bags.

When a pcell is instantiated, the system looks at the supermaster
for the pcell, and checks to see if a submaster (i.e. a variant) exists in
memory already with the same pcell parameter values as the one being
instantiated. If so, that is what is used for the instance. If not, a new
submaster is created by calling the pcell code with the set of requested
parameter values.

The pcell code is stored in the cellView itself, although it's not unusual for
more complex pcells to call additional SKILL functions which may be defined in
the environment - typically loaded from the libInit.il file within the library.

Property bags are used to hold CDF information (amongst other properties), but
that's not what you were asking here.

Best Regards,

Andrew.

 

There is a function to dump pcells, use it and you will have better
insight in what the pcell does, including access to the property bag and
use of the properties. As Andrew mentioned, the pcell probably calls
utility functions whose definition will not be able to see easily.

 

Andrew and Fogh,
thanks for making me understand this.

SS