Multi-supply voltage (MSV) driven SoC floorplanning for fast design convergence

摘要

With the ever-increasing power demands of consumer electronics and portable devices, multi-supply voltage (MSV) technique is supposed as one of the direct and effective ways for power optimization in SoC designs. To realize MSV implementation, procedures such as voltage assignment, voltage island partitioning and level shifters (LSs) placement should be considered simultaneously during the floorplanning stage. Although many works addressed the MSV-driven design problem, few of them actually took account of LS placement, which makes the generated results may limit the potential applications. Furthermore, existing design frameworks are often very computationally expensive, and it is not beneficial to shorten the time to market. In this paper, we present an MSV-driven SoC floorplanning framework for fast design convergence. Several techniques are proposed and integrated into an efficient and flexible non-randomized floorplanning algorithm. Firstly, to reserve the desired deadspace for the placement of LSs, the netlist is modified by assigning virtual LSs in the nets. Secondly, a heuristic based voltage assignment method is presented for accuracy and execution time trade-off. Thirdly, different from previous works which do voltage assignment without physical information feedback, an inner loop is built between voltage assignment and LS placement under the constraints of both timing and physical layout. Experimental results on Gigascale Systems Research Center (GSRC) benchmark suites indicate the proposed approach can improve power saving by 12%, CPU time by 48% with 4% area increase. (C) 2015 Elsevier B.V. All rights reserved.