An algorithm for two-layer channel routing

Abstract

In this paper we show that any two-terminal channel routing problem of density d can be solved in a two-layer grid of width ω=(3/2)d+O(1) by using a model in which two wires are permitted to overlap for not more than a constant distance. This is an asymptotical improvement over the best known result ω=2d−1. The algorithm presented here has the following additional properties: (i) there are at most 6 pairs of over-lapping edges for any two wires produced by it, (ii)it uses 6n contacts, where n is the number of nets to be connected, (iii)it can be implemented to run in time O(n). An extension of the algorithm to the multi-terminal problem is also discussed.