Automatic placement and routing method, automatic placement and routing apparatus, and semiconductor integrated circuit

Abstract

An automatic placement and routing method checks on a wiring density by scanning a measurement area defined on a routing layout pattern. If the wiring density exceeds an upper limit value, it automatically generates a layout pattern whose wiring density is less than an upper limit value by automatically carrying out one of the following steps: increasing wiring spacing; inserting a wiring inhibited region between wires; replacing a wire by a plurality of divided narrower wires; and forming part of the wiring on a different layer through contact holes. This makes it possible to solve problems of a conventional method in that narrowing a wire whose wiring density exceeds the upper limit value results in reducing reliability cause of an increase of the wire resistance and of the possibility of a break, and in that the design takes a lot of time because the replacement of the wiring requires much manpower.