MOTA: a MOSFET timing simulator

MOTA: a new NMOS and CMOS timing simulator, is presented. Basically, it employs a one sweep nonlinear Gauss-Seidal relaxation technique to decouple node equations, and this results in a linear performance on the computation time over the number of the gates of the circuit. It has three distinct features: (a) it provides a `SUBCIRCUIT¿ capability to simulate tightly-coupled circuit blocks. This solves the inaccuracy and the instability problems which are usually encountered in existing timing simulators, (b) it employs a physical table model for MOS devices with only 250 storage points, and (c) it utilises a simple variable time step control scheme and internal and external bypass schemes to increase the simulation speed. The run examples show that it is approximately 60 times faster than SPICE2G-5 while giving comparable precision.