Tailoring circuit-switched network-on-chip to application-specific system-on-chip by two optimization schemes

Abstract

As the number of cores on a chip increases, power consumed by the communication structures takes a significant portion of the overall power budget. In this article, we first propose a circuit-switched interconnection architecture which uses crossroad switches to construct dedicated channels dynamically between any pairs of cores for nonhuge application-specific SoCs. The structure of the crossroad switch is simple, which can be regarded as a NoC-lite router, and we can easily construct a low-power on-chip network with these switches by a system-level design methodology. We also present the design methodology to tailor the proposed interconnection architecture to low-power structures by two proposed optimization schemes with profiled communication characteristics. The first scheme is power-aware topology construction, which can build low-power application-specific interconnection topologies. To further reduce the power consumption, we propose the second optimization scheme to predetermine the operating mode of dual-mode switches in the NoC at runtime. We evaluate several interconnection techniques, and the results show that the proposed architecture is more low-power and high-performance than others under some constraints and scale boundaries. We take multimedia applications as case studies, and experimental results show the power savings of power-aware topology approximate to 49% of the interconnection architecture. The power consumption can be further reduced approximately 25% by applying partially dedicated path mechanism.