Method for testing the validity of initial-condition statements in circuit simulation, and correcting inconsistencies thereof

摘要

A method and a system for validating initial conditions (ICs) generally provided by a user when simulating a VLSI circuit are described. Inconsistent ICs sets are detected and replaced by consistent subsets thereof. The method selects the resistance and source values in a Norton or Thevenin circuit used to enforce the IC, and detects when specified ICs are inconsistent while preserving critical or fragile ICs when a two DC-pass approach is used. It further correlates the set of consistent ICs thus obtained with an equivalent circuit and simultaneously provides an input for future use. This allows a user to be notified and given a measure of how bad the inconsistencies are. Detecting inconsistencies is achieved either by measuring the holding current or by measuring the voltage drift if the two DC-pass approach is used.