METHOD OF DESIGNING SEMICONDUCTOR INTEGRATED CIRCUIT, DATA PROCESSING SYSTEM AND METHOD, AND METHOD OF DESIGNING ANALOGUE AND DIGITAL MIXED-INTEGRATED CIRCUIT

摘要

PROBLEM TO BE SOLVED: To relieve the unconvergence of a result of the circuit simulation by a Newton method.;SOLUTION: A simplified parameter is used in combination with a conventional method (A) in which only a regular parameter is used in a model expression of a circuit element (B). An operating point of the circuit is analyzed by the circuit simulation by the Newton method by using the simplified parameter obtained by simplifying a part of the parameter of the model expression to a value for canceling the significance of the parameter. When the solution is not converged, the presence of the error excluding that in the parameter of the model expression is determined. When the solution in the analyzing processing is converged, the converged solution is applied to a new initial value in the Newton method, and the similar analyzing is executed by using another simplified parameter or regular parameter when the degree of simplification is low. In the Newton method, as an analyzing time is shortened and the unconvergence hardly occurs, when the initial value is close to the final solution, a simulation time can be shortened and the unconvergence can be relieved by successively applying the result of the former convergence as the initial value to allow the value of the parameter to close to the regular value.;COPYRIGHT: (C)2002,JPO