Keeping hot chips cool

With 90nm CMOS in production and 65nm testing in progress, power has been pushed to the forefront of design metrics. This paper outline practical techniques that are used to reduce both leakage as well as active power in a standard-cell library based high-performance design flow. We discuss the design and cost issues for using different power saving techniques such as: power gating to reduce leakage, multiple and hybrid threshold libraries for leakage reduction and multiple supply voltage based design. In addition techniques to reduce clock tree power are presented as power consumed in clocks accounts for a significant portion of total chip power. Practical aspects of implementing these techniques is also discussed.