An optimum channel routing algorithm in the restricted wire overlap model

Abstract

In this paper we study the channel routing problem in the knock-knee mode with restricted edge overlap. We present an optimal algorithm which achieves t = d m with an overlap of O( m) edges between any two nets, where t is the number of tracks, d m is the density, and m is the multiplicity of nets. The algorithm improves upon the previous results of Sarrafzadeh [24] and has the properties: (1) it uses only vertical edge overlap; (2) it does not use any columns outside the channel; and (3) it connects adjacent terminals of a net by shortest wires. Furthermore, our algorithm reduces the overlap between two nets from O( m 2) to O( m). The running time of the algorithm is O( d m nm), where n is the number of nets.