I'm trying to connect vdd and vss nets to instance pins and the command
> globalNetConnect vdd_net -type pgpin -pin VDD_pin -inst instance_name -verbose
executes as expected and creates the connection. However, the command for vss connection
> globalNetConnect vss_net -type pgpin -pin VSS_pin -inst instance_name -verbose
returns the following message:
**ERROR: (ECNDB-1220): A global net connection rule for connection 'VSS_pin' of cell '...' to a global net '...' was specified. But the connection can not be made because the pin and the global net are not of the same polarity. Check the rule, and correct the issue.
I have examined the lef file of the instance to whose pin I want to connect the vss and the declaration of the pin (apart from USE GROUND vs. USE POWER) is exactly the same, both are 'INOUT'. I would love some suggestions on where to look for the polarity and how to resolve the problem.
The nets are analog power supplies comming from pins, through a clamp.