PERFORMANCE COMPUTATION FOR PRECHARACTERIZED CMOS GATES WITH RC LOADS

For efficiency, the performance of digital CMOS gates is often express ed in terms of empirical models. Both delay and short-circuit power di ssipation are sometimes characterized as a function of load capacitanc e and input signal transition time. However, gate loads can no longer be modeled by purely capacitive loads for high performance CMOS due to the RC metal interconnect effects, This paper presents a methodology for interfacing empirical gate models to reduced order RC interconnect models in terms of a nonlinear iteration procedure. The delay and pow er are calculated with errors on the same order as those for the origi nal empirical equations. Moreover, a linear equivalent gate model is g enerated which accurately captures the delays at the interconnect fan- out nodes.