NonHanan Routing

This work presents a Steiner tree construction procedure, MVERT, to meet specified sink arrival time constraints. It is shown that the optimal tree requires the use of nonHanan points. The procedure works in two phases: a minimum-delay Steiner tree is first constructed using a minor variant of the SERT procedure, after which the tree is iteratively modi#ed, using an efficient search method, to reduce its length. The search method exploits the piecewise concavity of the delay function to arrive at a solution efficiently. Experimental results show that this procedure works particularly well for technologies where the interconnect resistance dominates, and significant cost savings are shown to be generated