INTEGRATION OF LOW-POWER DIGITAL CIRCUITRY INTO UNDERGRADUATE CURRICULA

摘要

Power-aware computing has become in recent years a significant area of research and development in both academia and industry. Various techniques for reducing the temporal power and the long term energy consumption of embedded processors in general and mobile devices (e.g., cellular phones, PDAs and laptop computers) in particular, have been developed. Several new products whose main feature is lower power consumption have been introduced successfully into the marketplace. The techniques developed for achieving the reduced power and energy cover many phases of the computer system design including circuits, voltage scaling, micro-architectures and system software (i.e., operating systems and compilers). Over the last ten years or so, power-aware computing has been transformed from a somewhat arcane and limited discipline to one of the most active areas in computer science and engineering. This trend has been fueled by the following: Processors are becoming ever more power-hungry, and their power densities (watts/cm{sup}2) are increasing rapidly. The power density of many modern processors exceeds that of a hotplate and that of the core of a nuclear reactor. The problem of dissipating heat from a microprocessor is therefore becoming more acute. As feature sizes shrink, the fraction of energy lost to leakage will become significant. Leakage rises very rapidly with temperature: so running a processor hot will further increase power consumption, thereby setting up a positive feedback loop. Further, the processor failure rate increases with an increase in the operating temperature. Battery-powered applications have proliferated. Battery technology has not advanced as rapidly as processor power consumption, and this limits the mean time between recharges. The more obvious approaches to constraining power consumption, such as disk spindown and turning off the screen have already been implemented. More complex approaches are now being pursued for additional savings. The aggregate power consumption of computers is no longer a negligible fraction of the total power consumption in the United States. Approaches to reduce such power consumption can therefore be expected to make a measurable impact on the overall power consumed in the country.