Design Of Nonblocking Multistage Optical Network-on-chip

With the size of the electronic devices reduction, more and more the number of processor cores integrated the signal chip make the traditional electrical interconnection network-on-chip become a bottleneck in the communication bandwidth, energy consumption and latency. With the silicon optics technology development, the merits of the optical interconnection technology, including high bandwidth, high throughput, low energy, will be a new research hotpot for the network-on-chip applications. To reduce network congestion and improve communication quality, the wavelength routing technology is common. We study two typical passive optical interconnection architectures based on wavelength routing which are ?-router and GWOR(Generic Wavelength-routed Optical Router), and summarize their basic architectures and communication process. The analysis results show that the scalability of two network architectures is bad and the transmission bandwidth is fixed.In view of the problem of the network scale expansion restricted the number of the wavelengths, we propose a scalable multistage optical interconnection network-on-chip. This architecture uses multiple basic switching fabrics based on passive microring resonators(MRs), and designing the interconnection principle achieves nonblocking communication with less number of wavelengths. Finally, we analysis the number of the MRs and wavelengths, the insertion loss and area cost. The results show the proposed multistage optical interconnection network-on-chip has better advantages on the number of the wavelengths and the insertion loss.To solve the problem of the fixed transmission bandwidth, we present an active multistage optical interconnection network-on-chip which the bandwidth allocation is flexible. The architecture is made up of multiple switching fabrics. Each switching fabric consists of active broadband MRs, passive narrow MRs and the control unit. According to the characteristic of the network flows, controlling the state of the broadband MRs achieves the communication mechanism of signal wavelength and multiple wavelengths to mitigate the problem of the fixed transmission bandwidth. The simulation result of OPNET shows this network architecture has better performance of the latency and throughput.