Lazy Logic: Minimizing Activity to Reduce Processor Power Consumption

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

Abstract The proposed research investigates lazy logic, a new design philosophy that has the potential to address many of the technological challenges that arise with nanometer-scale CMOS devices. Lazy logic rests on three principles: minimum clocking, which demands designs that use clocked storage only whenever absolutely required for correctness; pipeline avoidance, which encourages logic structures with multicycle delay paths and a scarcity of clocked latches; and lazy release, which promotes a lax resource allocation policy that avoids the power and delay overhead of utilization-efficient resource sharing by greedily holding onto resources across multiple invocations. When judiciously applied--either individually or in concert--these policies result in designs that are a better match for the realities of future nanometer technologies, since they reduce dynamic power, operating temperature, and relative static power. Furthermore, such designs are more tolerant of process variation, more likely to mask and less likely to latch and propagate combinational logic soft errors, and, due to their lower operating temperature and reduced activity rates, less prone to lifetime reliability problems. These benefits are realized with little to no detrimental effect on bandwidth or latency, and can result in surprising improvements in performance. The research will have a specific and significant impact on the logic design and computer architecture communities, since it requires development and analysis of interesting and representative workloads, realization of state-of-the-art simulation and design infrastructure, and invention of powerful and useful evaluation methodologies. Since most of the development and research work will be conducted by graduate students, industry and academia will benefit from well-educated and trained employees as well as direct technology transfer when students graduate and begin employment elsewhere. Finally, the techniques and methods created will be applied towards the development of increasingly powerful and ubiquitous computing devices whose utility will have a substantial impact on the productivity and creativity of countless end users.