Clock mesh synthesis method using the Earth Mover's Distance under transformations

Abstract

A novel clock mesh generation method is proposed based on the EMDg (Earth Mover's Distance under transformations) algorithm. A bottom-up approach is adopted in creating local-level tree clusters to drive the generation of a regional-level uniform clock mesh. The EMDg method incrementally moves the regional-level uniform clock mesh closer to the register cluster roots in order to reduce the total stub wirelength. Post-EMDg mesh reduction, the redundant mesh wires are eliminated from the initial uniform mesh in order to reduce the mesh wirelength, preserving the stub wire connections and the integrity of the clock mesh. The optimization results show that the proposed method can achieve an average total wirelength saving of 20.1% and power savings of 12.2% on a suite of ISCAS'89 benchmark circuits compared to the previous clock mesh generation methods.