Gravity

Abstract

Three dimensional integration is an increasingly feasible method of implementing complex circuitry. For large circuits, which most benefit from 3-D designs, efficient placement algorithms with low time complexity are required.We present an iterative 3-D placement algorithm that places circuit elements in three dimensions in linear time. Using an order of magnitude less time, our proposed algorithm produces placements with better than 11% less wire lengths than partitioning placement using the best and fastest partitioner. Due to the algorithms iterative nature, wire-length results can be further improved by increasing the number of iterations.Further, we provide empirical evidence that large circuits benefit most from 3-D technology and that even a small number of layers can provide significant wire-length improvements.