Mixed wire and surface-wave communication fabrics for decentralized on-chip multicasting

Network-on-chip (NoC) has emerged to tackle different on-chip challenges and has satisfied different demands in terms of high performance, economical and reliable interconnect implementation. However, a merely metal-based interconnect reaches performance bound with the relentless technology scaling. Especially, it displayed a bottleneck to meet the communication bandwidth demand for multicasting. This paper proposes a novel hybrid architecture, which improves the on-chip communication bandwidth significantly using mixed wires and surface wave interconnects (SWI) fabrics. In particular, the bandwidth of multicasting can be drastically improved. We introduce a decentralized arbitration method to fully utilize the slack-time scheduling with deadlock-free flow control. Evaluation results, based on a cycle-accurate and hardware-based simulation, demonstrate the effectiveness of the proposed architecture and methods. Compared to a wire-based NoC, the mixed fabric approach can achieve an improvement in power reduction and communication speed up to 63% and 12X, respectively. These results are achieved with almost negligible hardware overheads. This new paradigm efficiently addresses the emerged challenges for on-chip communications.