GLOBAL WIRING FOR CUSTOM LAYOUT DESIGN.

A method for global wiring in a fully automated custom layout design environment is described. Its purpose is to assign nets and module pins to wiring spaces, while using possible flexibility and porosity of the modules. The routing algorithm itself, a kind of Steiner tree heuristic runs against a background of constant data structures, and has two stages: first the topology of the tree is determined, and then the optimum tree with that topology is selected.