ON GENERAL ZERO-SKEW CLOCK NET CONSTRUCTION

We propose a simulated annealing based zero-skew clock net constructio n algorithm that works in arny routing spaces, from Manhattan to Eucli dean, with the added flexibility of optimizing either the wire length or the propagation delay. We first devise an O(log n) tree grafting pe rturbation function to construct a zero-skew clock tree under the Elmo re delay model. This tree grafting scheme is able to explore the entir e solution space asymptotically. A Gauss-Seidel iteration procedure is then applied to optimize the Steiner point positions. Experimental re sults have shown that our algorithm can achieve substantial delay redu ction and encouraging wire length minimization compared to previous wo rks.