Compared to conventional Steiner tree signal net routing, non-tree topology is often superior in many aspects including timing performance, tolerance to open faults and variations. In nano-scale VLSI designs, interconnect delay is a performance bottleneck and variation effects are increasingly problematic. Therefore the advantages of non-tree topology are particularly appealing for timing critical net routings in nano-scale VLSI designs. We propose Steiner network construction heuristics which can generate either tree or non-tree of signal net with different slack wirelength tradeoffs, and handle both long path and short path constraints. Extensive experiments in different scenarios show that our heuristics usually improve timing slack by hundreds of pico seconds compared to traditional tree approaches while increasing only slightly in wirelength. These results show that our algorithm is a very promising approach for timing critical net routings.

Compared to conventional Steiner tree signal net routing, non-tree topology is often superior in many aspects including timing performance, tolerance to open faults and variations. In nano-scale VLSI designs, interconnect delay is a performance bottleneck and variation effects are increasingly problematic. Therefore the advantages of non-tree topology are particularly appealing for timing critical net routings in nano-scale VLSI designs. We propose Steiner network construction heuristics which can generate either tree or non-tree of signal net with different slack wirelength tradeoffs, and handle both long path and short path constraints. Extensive experiments in different scenarios show that our heuristics usually improve timing slack by hundreds of pico seconds compared to traditional tree approaches while increasing only slightly in wirelength. These results show that our algorithm is a very promising approach for timing critical net routings.