Automatic Routing Algorithm for VLSI

Because most LSI layout systems use the Channel Assignment method for routing, they have disadvantages in which block outlines, terminal positions, and placement of blocks are restricted for some reasons and layers with the multilayer routing are used ineffectively. We have successfully developed the LSI layout system that handles up to polygon blocks with arbitrary outlines by remodeling the line search method often used for PCB routing. This paper describes the accelerating of the line search method.