OPRON: a new approach to planar OTC routing

In this paper we solve the planar over-the-cell routing problem, in which nets must have at least one terminal on the boundary. Such nets allow for nontraditional cell designs, where all terminals must be placed on the boundaries giving a degree of freedom to the cell designer. We present a dynamic programming algorithm that optimally solves this problem, in O(K/sup 2/n/sup 4/) time, where K is the number of tracks available over the cell for a given cell row region, and n is the number of nets to be routed.