Current-limited switch-level timing simulator for MOS logic networks

An algorithm for switch-level timing simulation of MOS logic networks is proposed. The event-driven simulator, WATSWITCH, partitions the circuit into subblocks which are solved by replacing each transistor by a special current-limited switch. Because of the choice of the switch model, time-domain responses are obtained without model evaluations during the simulation, without table lookup, and without time-domain integration. This is achieved by allowing only capacitors and piecewise-constant current sources to be the elements of the simulator. Because resistors are not allowed, the time responses are known to be piecewise-linear segments. As a consequence, neither numerical integration nor transistor model evaluation is needed during the simulation