Nanosim is a transistor-level power simulator and analyzer for CMOS and BiCMOS circuit designs. As more components are integrated into a tiny silicon chip, power consumption becomes a major concern. Nanosim is used to find excessive consumption of power through current analysis. In CMOS Nanosim calculates the switching current, caused by switching and node capacitance, the leakage current, caused by floating nodes, and short circuit current, caused by rise/fall times and dc contentions.
Pathmill is an analysis tool you can use to find critical paths and verify timing in semiconductor designs. It employs a static and mixed-level timing analysis to process transistor, gates, and timing models. It calculates timing delays, performs path searches, and checks timing requirements simultaneously.
Timemill catches design errors and timing problems during the design phase. This gives you the flexibility of more iterations to optimize your design. The switch and transistor-level models closely simulate the physical behavior of MOS devices.
NOTE: Filename extensions do matter. ".spi" != ".cir"