Maximizing the Communication Parallelism for Wavelength-Routed Optical Networks-On-Chips

Enabled by recent development in silicon photonics, wavelength-routed optical networks-on-chips (WRONoCs) emerge as an appealing next-generation architecture for the communication in multiprocessor system-on-chip. WRONoCs apply a passive routing mechanism that statically reserves all data transmission paths at design time, and are thus able to avoid the latency and energy overhead for arbitration, compared to other ONoC architectures. Current research mostly assumes that in a WRONoC topology, each initiator node sends one bit at a time to a target node. However, the communication parallelism can be increased by assigning multiple wavelengths to each path, which requires a systematic analysis of the physical parameters of the silicon microring resonators and the wavelength usage among different paths. This work proposes a mathematical modeling method to maximize the communication parallelism of a given WRONoC topology, which provides a foundation for exploiting the bandwidth potential of WRONoCs. Experimental results show that the proposed method significantly outperforms the state-of-the-art approach, and is especially suitable for application-specific WRONoC topologies.