In this work, we propose a dynamic power-aware issue queue in a general-purpose microprocessor for multimedia applications. Its resources can be adapted at runtime in accordance with the feedback from a formal closed-loop control system such that power dissipation is reduced while the system still meets the real time target for multimedia applications. We partition the issue queue into multiple sets (i.e., FIFOs) such that only instructions at the head of each set are able to issue. We then dynamically reconfigure the issue queue by changing the number and/or size of FIFOs to satisfy specific application’s needs. The optimal configuration and timing are predicted by the closed-loop control system. We implement a simple and stable control system with a dynamically reconfigurable issue queue. Our results show an average power savings of over 90% in the issue queue with a negligible affect on the performance.
Yu Bai, R. Iris Bahar