Temporal and spatial idleness exploitation for optimal-grained leakage control

Runtime leakage control techniques, such as power gating (PG) and body biasing (BB), have been applied in a coarse-grained manner traditionally. In order to enable more aggressive leakage reduction, researchers are seeking ways to control leakage with finer granularity. Our research proposes two novel methods, namely circuit clustering for temporal and spatial idleness exploitation, to systematically reduce the granularity of leakage control and improve leakage reduction. Another strength of this paper is the quantitative study of leakage saving and control cost by leakage control with different granularity. With our quantitative study, designers can make the trade-off between leakage saving and control cost, and decide the optimum granularity for leakage control. A heuristic algorithm has been developed to automate the two circuit clustering methods and determine the optimum granularity for any given circuit. The analysis and experiments of this paper is mainly based on RBB. They are also applicable to PG by modifying the cost function.