I am having some trouble simulating the layout that I have synthesized using SOC Encounter. The problem seems to be that the simulator (SpectreS) does not find global signals VDD! and GND!. I have pads for power and ground signals on my layout.
I have set the name of the pad for power to VDD (not a global signal) and set its "expression" property to "vdd!". The simulator does not throw any error. However, if change the pad name to VDD! (and GND!), the simulator shows error telling me that it needs a "string". I do not get any more information than this.
I simulated my schematic that was also generated by Encounter, and things look fine. I did not carry out the full LVS though.
I had seen the same (incorrect) results during simulation of schematics when my global signals were not configured. For the schematic case, I could find the global signals (VDD!, GND!) listed in the stimuli creation window (global signals section), but I cannot find the same for layouts. Setting these global signals in the schematic case got the circuit working as expected.
So, as I suppose, the problem here seems to be configuring the global signals in the extracted layout. Can someone please provide a clue on how it should be done?
If the problem is different, can someone please help me fix it?
Thanks for your time