Classic PCells are: MOS, interdigitated resistors, input pairs, mom-cap, balun and inductors.
I just want to know what is the most complex PCell you have ever seen or designed.
Do someone of you uses more complex Pcells than those listed above?
If anything more electrical related property is need for built up of an OPAMP or SRAM generic cells restriction only on geometric properties within the module generator development and usage is useless. So all real module generators are using higher language script and debugging enviroments and are not limited to layout views.