Modeling and optimization of low power resonant clock mesh

Power consumption is becoming more critical in modern integrated circuit (IC) designs and clock network is one of the major contributors for on-chip power. Resonant clock has been investigated as a potential solution to reduce the power consumption in clock network by recycling the energy with on-chip inductors. Most of the previous resonant clock work focuses on H-tree structures, while in this work, we propose a modeling and optimization method for the mesh structure, which suffers from the high power consumption more seriously than the tree structure. Closed-form expressions for the transfer function, skew, and power are derived. Based on these expressions, impacts of design factors, such as the buffer size, LC tank location, grid size, wire width, and the sparsity of buffers and LC tanks, are fully explored to make trade-offs among power, skew, and area, which can be used as design guidelines for top level resonant clock mesh in early design stages. The exploration is also extended to 3D ICs and different mesh structures are evaluated. Matlab-based implementation of the proposed simplified circuit model can achieve over 105 times speedup compared to SPICE-based simulation.