Energy optimization of FPGA-based stream-oriented computing with power gating

In this paper, we propose a technique to improve the energy efficiency of FPGA devices by exploiting power gating during idle periods in streaming applications. The main idea is to shuffle idle periods during application execution so that the energy and timing overheads of turning the FPGA on and off can become acceptable. A key requirement is that fast FPGA-based accelerators are available and that the application follows a repetitive nature of execution. In this case, the accelerators work on a successive computing mode to accumulate the idle intervals in different iterations in order to make power gating feasible. Streaming on demand applications which are ubiquitous in embedded and portable devices are very good candidates to benefit from this technique. A case study is presented based on an MP3 player as the streaming application which shows up to 52.9% energy reduction.