Buffer Sizing for Clock Networks Using Robust Geometric Programming Considering Variations in Buffer Sizes

摘要

Minimizing power and skew for clock networks are critical and difficult tasks which can be greatly affected by buffer sizing. However, buffer sizing is a non-linear problem and most existing algorithms are heuristics that fail to obtain a global minimum. In addition, existing buffer sizing solutions do not usually consider manufacturing variations. Any design made without considering variation can fail to meet design constraints after manufacturing. In this paper, first we proposed an efficient optimization scheme based on geometric programming (GP) for buffer sizing of clock networks. Then, we extended the GP formulation to consider process variations in the buffer sizes using robust optimization (RO). The resultant variation-aware network is examined with SPICE and shown to be superior in terms of robustness to variations while decreasing area, power and average skew.