PLMAP — A piecewise linear MOS circuit analysis program

In this paper we describe a MOS circuit simulation program PLMAP (Piecewise Linear MOS Circuit Analysis Program) which performs efficient time domain simulation of LSI MOS circuits. PLMAP uses a piecewise linear model for MOS transistors. It uses a relaxation method to analyze the piecewise linear circuit at one time point after another. The relaxation method consists of a 2-level decomposition which partitions the whole circuit into 2-level subcircuits and a scheduling method which determines the sequence of analysis of subcircuits. At each time point, the subcircuits are analyzed sequentially and iteratively by using Gauss-Seidel iteration together with a prediction formula to determine the initial guess of solution. Experiences have shown that PLMAP is more efficient in MOS circuit analysis than spice.