Method and apparatus for global routing, and storage medium having global routing program stored therein

摘要

A global routing method acquiring global routing between net terminals of cells placed on a VLSI chip. First, a Steiner tree is generated without any of constraints such as layers, prohibition and a wiring capacity as an initial solution. Then, partial correction of the Steiner tree is repeated so as not to increase a line length as far as possible in consideration of constraints such as a prohibiting region, a wiring capacity and layers based on the initial solution of the Steiner tree to obtain the global routing. The Steiner tree is corrected generating a path collection obtained by dividing the Steiner tree into a plurality of paths each having at least a Steiner point, as a value, being an intersection of 3 or more branches.