An Efficient Path Setup for a Hybrid Photonic Network-on-Chip

Electrical network-on-chip (NoC) faces critical challenges in meeting the high performance and low power consumption requirements for future multicore processors interconnection. Recent tremendous advances in CMOS compatible optical components give the potential for photonics to deliver an efficient NoC performance at an acceptable energy cost. However, the lack of in flight processing and buffering of optical data made the realization of a fully optical NoC complicated. A hybrid architecture which uses optical high bandwidth transfer and an electrical control network can take advantage of both interconnection methods to offer an efficient performance-per-watt infrastructure to connect multicore processors and system-on-chip (SoC). In this paper, we propose a predictive switching and a reservation based path setup techniques to reduce the path setup latency of such hybrid photonic network-on-chip (HPNoC). By using these techniques, it is possible to reduce the latency for end-to-end communication in a HPNoC improving its overall performance. In the simulation, we use a cycle accurate simulator under uniform, neighbor, and bitreversal traffic patterns for a 64-node torus topology. The results show that the proposed techniques considerably improve the overall latency of HPNoC.