A Survey of Multicast Communication in Optical NetworkonChip (ONoC). Optical NetworkonChip (ONoC) is an emerging chiplevel optical interconnection technology to realise highperformance and powerefficient intercore communication for manycore processors. For onchip networks, multicast communication is an important communication pattern, which is not only widely used in parallel computing applications in Chip MultiProcessors (CMPs), but also commonly adopted in emerging areas such as neuromorphic computing. However, the optimisation of multicast communication in an ONoC is not well studied and there is a significant room to improve the performance. In this paper, we present a comprehensive survey of the multicast communication in an ONoC, covering the development of both architecture design and networking design as well as our recent research outcomes. Moreover, we propose the design challenges and future research directions for optimising multicast in an ONoC, which can provide guidance and insight for the future researchers and chip developers.

Balancing Performance and Energy Efficiency of ONoC by Using Adaptive Bandwidth Onchip optical links can consume considerable energy. Previous work shows that there exists a tradeoff between the optical link bandwidth and energy consumption. In this paper, we analyze the temporal behavior of onchip communication in typical applications and make the following observation: both ONoC and processor cores are not always busy, and there are significant amounts of time during which these components are relatively idle. Base on such an observation, we present a novel technique called Shifting Link to dynamically changing the bandwidth for optical link according to the workload situation. To evaluate our proposed method, we implement the Shifting Link in FlexiShare ONoC architecture. The experiment result shows that, on geometric mean, Shifting Link reduces the energy consumption by 35.0% with only 5.8% decrease in the performance.