Routability checking for general area routing problems

This paper presents a scheme for checking the routability of nets for use in general area routing problems (GARPs). The scheme is based on the extended Pascal's triangle method which was previously proposed as a routability measure for GARPs. It also uses the counting method of Pascal's triangle for determining the number of potential routes of each net. However, instead of performing a comprehensive analysis for each net, the new scheme considers a subset of grids within the net's bounding box for fast routability determination. This technique detects if the nets will be potentially routable in the presence of arbitrary obstacles including possible limitations on the number of vias/bends. Experimental results of the proposed technique are presented.