Vertex-disjoint trees and boundary single-layer routing

Abstract

In the boundary single-layer routing problem (BSLR), there is a planar graph, a collection of terminals on the boundary of the infinite face and a set of multi-terminal nets. A solution of BSLR consists of a set of vertex-disjoint trees interconnecting the terminals belonging to the same (multi-terminal) net. An algorithm, unifying and generalizing previous BSLR algorithms, to solve an arbitrary instance of BSLR, is presented. Problems involving slidable terminals (i.e., when terminals can slide within a certain range on the boundary) and permutable terminals (i.e., when positions of some terminals [going to the same gate] can be interchanged) are optimally solved. The proposed algorithm runs in O (e) time, where e is the number of edges in the input graph. The result is extended to handle gridless routing environments.KeywordsPlanar GraphInput GraphTopological RealizationArbitrary InstanceVLSI LayoutThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.