Exact switchbox routing with search space reduction

We present an approach for exact switchbox routing that complements traditional routing techniques. It is particularly well suited for an application to dense problem instances and the completion of routing in subregions which turn out to be difficult for routing tools based on heuristic methods. The exact router proposed used symbolic methods i.e. MDDs (Multi-valued Decision Diagrams) for representation of the routing space. All possible solutions to the routing problem are represented by one single MDD and once this MDD is given, routability can be decided within constraint time. To reduce the search space of possible routing solutions, so-called forced cells are computed. Finally, experimental results are given. They show the feasibility and the practicability of the approach.

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