EMOTA: an event-driven MOS timing simulator for VLSI circuits

Abstract

A novel new event-driven MOS timing simulator for VLSI circuits, EMOTA, is present- ed. The traditional event-driven simulation scheme used in logic simulation is modified for use in this circuit level timing simulator. The fast per- formance is due to the result of mixing the new derived event-driven algorithm and its associated time-wheel control mechanism, together with the unidirectional nonlinear Gauss-Seidel relaxation technique to decouple the circuit equations. EMOTA allows both interactive and batch simu- lation modes and its input format is the same as SPICE. The simulation speed of EMOTA is shown to be more than 300 times faster than SPICE2G.5 for circuits of several hundred tran- sistors and the simulated waveforms have accept- able accuracy.