CustomSim has the capability for analysis of IR drop and electromigration in power and ground busses, while simultaneously accounting for the effects of interconnect resistance on dynamic circuit performance. The unique direct-coupled methodology provides highly accurate measurement of power bus currents, by performing full circuit simulation in the presence of back-annotated parasitics. CustomSim overcomes the limitations of simulation with millions of extracted parasitic resistors, by incorporating built-in compression and reduction algorithms to maintain accuracy, capacity and performance.
In the proprietary methodology accurate transient current waveforms are acquired during dynamic simulation, and are used for detailed measurement of IR drop and current density in the complete, un-reduced power and ground nets. Other less-accurate approaches to power-net analysis estimate IR drop by characterizing cells before they are placed into a circuit layout, where the true in-silicon effects will be seen. Graphical output in GDSII and other formats allows designers to overlay results on their layout design for analysis and debug.