Virtual power rails for integrated circuits

Abstract

Methods and apparatuses to decrease power consumption and reduce leakage current of integrated circuits are disclosed. New leakage power saving techniques for various types of integrated circuits, including cache memory circuits, are discussed. Embodiments comprise methods and apparatuses to reduce power consumption in integrated circuits by using virtual voltage rails, or virtual power rails, to supply power to integrated circuit loads. The methods and apparatuses generally involve using one or two virtual power control devices to 'head' and 'foot', or sandwich, the integrated circuit loads from firm power supply rails. In these method embodiments, one or more elements sense the voltage of the virtual power rails, or nodes, and make adjustments to control the voltage at certain “virtual” voltage potentials. While controlling the voltage in this manner, the virtual power control devices may serve to restrict unnecessary current flow through the integrated circuit loads.