Hi, Pancho_hideboo! Thanks for trying to help. Someone else solved the problem, so here's the solution for others to prevent lost time/agonizing. Virtuoso is a GUI interface, where the netlists are generated with a click of a bottom (this is what's meant by automatically) from drawn pictures of the circuits. When selecting the voltage pulse source in Virtuoso, there is a properties option used to fill out whatever properties of the signal wanted. Generally, not all the properties need to be filled out, and netlists will be generated regardless of the properties. The issue is that for Hspice simulators, there is a certain amount of properties that need to be filled out (in other words, the set properties follow the same syntax as in the code, whereas Spectre doesn't care about this minor difference). If the correct number of properties are filled out, the generated netlist will generate the correct waveform. If not, a netlist is still generated but with incorrect waveforms.