Hybrid structured clock network construction

Abstract

This paper hierarchically constructs a hybrid mesh/tree clock network structure consisting of overlying zero-skew clock meshes, with underlying zero-skew clock trees originating from the mesh nodes. We propose a mesh construction procedure, which guarantees zero skew under the Elmore delay model, using a simple and efficient linear programming formulation. Buffers are inserted to reduce the transition time (or rise time). As a post-processing step, wire width optimization under an accurate higher-order delay metric is performed to further minimize the transition time and propagation delay/skew. Experimental results show that the hybrid mesh/tree construction scheme can provide smaller propagation delay and transition time than a comparable clock tree.