Power Savings in MPSoC

Abstract: High performance integrated circuits suffer from a permanent increase of the dissipated power per square millimeter of silicon, over the past years. This phenomenon is driven by the miniaturization of CMOS processes, increasing packing density of transistors and increasing clock frequencies of microchips, thus pushing heat removal and power distribution to the forefront of the problems confronting the advance of microelectronics. In the opposite direction is the market growth of mainstream portable devices, which require extremely low power consumption. These evolving factors brought power dissipation into play and transformed it into a major design metric. This thesis comprises those knowledge and methodological tools that can offer a preliminary safe path toward less power-hungry SoC and MPSoC designs, thus contributing towards a holistic approach of power-related effects. This is accomplished by providing the essential theoretical background of CMOS power dissipation, investigating a vast range of power saving techniques and plotting their classifications, according to the power components each technique is meant to suppress and, the level of abstraction that it can be applied at, thus facilitating proper decision making about which power saving techniques to apply on a certain design. Moreover, this thesis implements, demonstrates and evaluates generic power analysis and optimization flows that are based on the ASIC industry’s de facto standard Synopsys tools. The tools’ actual capabilities are contrasted to the theoretical expectations and the chief tradeoffs that are involved in terms of speed versus accuracy and attainable power savings versus abstraction level are stressed. Our extracted power results, for an Ericsson’s large ASIC block, show that by putting emphasis on coping with power early, thus enhancing typical synthesis flows with an appropriate set of techniques, significant savings can be achieved for both dynamic and static power components in the front-end synthesis domain.