Microarchitecture Floorplanning for Sub-threshold Leakage Reduction

Abstract

Lateral heat conduction between modules affects the temperature profile of a floorplan, affecting the leakage power of individual blocks which increasingly is becoming a larger fraction of the overall power consumption with scaling of fabrication technologies. By modeling temperature dependent leakage power within a micro architecture-aware floorplanning process, we propose a method that reduces sub-threshold leakage power. To that end, two leakage models are used: a transient formulation independent of any leakage power model and a simpler formulation derived from an empirical leakage power model, both showing good fidelity to detailed transient simulations. Our algorithm can reduce subthreshold leakage by up to 15% with a minor degradation in performance, compared to a floorplanning process that does not model leakage. We also show the importance of modeling whitespace during floorplanning and its impact on leakage savings