Method of optimizing signal lines within circuit, optimizing apparatus, recording medium having stored therein optimizing program, and method of designing circuit and recording medium having stored therein program for designing circuit

Abstract

A method for designing an integrated circuit such as a VLSI circuit, in particular optimizing delay of a signal transmitting through signal lines connecting a signal supplying source to each of elements, whereby skew can be decreased. The method can include determining whether the signal source satisfies a fan-out restriction if the signal source supplies a signal to all of the driven elements which are directly connected to the signal source, dividing the elements into groups so that the fan-out restriction is satisfied in each of the groups and each of the groups has the same or substantially same load capacity, when the signal source does not satisfy the fan-out restriction, and inserting into each group, a buffer having a size which makes the groups of elements satisfy the fan-out restriction. The dividing and the buffer inserting are repeated until a positive determination is delivered on the fan-out restriction.