Just some pcell info

Paul,

Of course generating schematic PCells with PCell Designer is easier (see Generating a Schematic Parameterized Cell using PCell Designer ) but if you're going to create them using SKILL, the key things you need to be aware of are:

1. You specify the viewType in the pcDefinePCell as "schematic" (this is the optional fourth argument of the list passed as the first argument)
2. The primary need is that the PCell must create the connectivity - the schematic extractor is not run, and so for the netlist to make any sense it must have connectivity in the database (so that means instances, instTerms, nets and terminals)
3. You can't use "sch" functions to create the PCells - the rules about PCell-safe functions are the same as for layout (because it needs to work in standalone executables like dbAccess and si - for CDL netlisting, for example)
4. The physical information (e.g. wires, pins) are often a good idea to add because:
   1. It gives the user something understandable to look at if they descend read into the instance (of course, it's your responsibility to ensure that the graphics match the connectivity you create)
   2. The user can then probe the wires if they want to save something (of course, this means that the wire must be attached to the net)
   3. You could annotate operating point data onto the instances, for example.

Regards,

Andrew