I'm using ELC to characterize my design library in UMC 130 nm technology. All of my cells except the flipflops have been characterized and I'm getting errors that some of the Hspice simulation fails for the flipflops. I see some weird things like the GND pin is treated as an input pin and Hspice tries to assign some signal to it. Obviously the tool won't recognize this cell as a flipflop. Can anyone help me with this?