An efficient three‐layer channel routing algorithm without vertical violation

Abstract

AbstractThis paper proposes a three‐layer channel routing algorithm for a new HVH routing method using the graph‐theoretic technique aiming at the minimization of the routing area. In the proposed method, the total net list is given as the input.To realize the routing with the lower bound for the number of tracks, the following steps are executed. First, the net requiring the routing with priority is selected based on the channel graph. Then, using that net as the core, the net group that can be assigned to the present track is constructed using the graph‐theoretic technique. The proposed method has the advantage that no vertical violation is produced between different nets nor is the stacked contact produced essentially within the same net.As a result of computer experiment for several well‐known problems, solutions with the minimum number of tracks are obtained. It should especially be noted that the vertical violation is not produced even in Deutsch's difficult problem. The routing can be realized within the lower bound for the number of tracks without the short vertical wire (where a short vertical wiring is employed in the horizontal wiring layer).