Design And Exploration Of A Double-layer Optical Networks-on-chip Based On Virtual-cluster

Currently,with the rapid development of big data,cloud computing,artificial intelligence and other fields,single core processing chips are not competent for massive data analysis and multi task current affairs computing.Proven on-chip semiconductor integration technology makes multiprocessor system-on-chip(MPSoCs)the preferred solution for chip design.However,with the expansion of the function and scale of traditional electrical networks-on-chip(ENoCs),the limited power budget of MPSoCs is difficult to support the high power loss of metal interconnection.Optical networks on chip(ONoCs)is a new on-chip multi-core interconnection technology which uses optical instead of electrical interconnection.Compared with ENoCs,its characteristics of higher bandwidth density,lower communication delay and on-chip power consumption attract more and more enterprises and researchers' attention.In the multi-core architecture based on ONoCs,the interconnection network,as the communication infrastructure,realizes the data interaction between the processing cores(IP).In the design process of ONoCs,topology is one of the key factors that determine the performance of the network.It not only has a great impact on the performance of the network on chip(such as delay and throughput),but also relates to the power consumption of the system,the reliability of network communication,and the expansion of the network.Among many on-chip topologies,mesh topology is a typical topology.Because of its regular structure,excellent network performance and good scalability,mesh topology is considered as one of the most important choices in ONoCs design.However,due to the low connectivity of mesh topology,the ability of data exchange between IP cores on chip is greatly limited.In addition,a large number of silicon-based optical devices are integrated in ONoCs,which inevitably suffer a series of power loss and crosstalk noise due to their manufacturing process and physical characteristics.In the mesh-ONoCs,there are a large number of long Manhattan distance communication node pairs.Insertion loss and crosstalk accumulate rapidly in the process of long-distance communication,resulting in signal degradation,distortion,distortion,and greatly reducing the quality of on-chip communication.In order to solve the above problems,this paper proposes a double-layer optical interconnection network based on virtual cluster architecture,which is named VCmesh.Mesh network is laid in the lower layer of the network structure,and it is divided into several virtual clusters.Then,these clusters are interconnected through the upper layer of allpass optical switching network.Therefore,there are two candidate communication paths between the source node and destination node.One is the original path based on XY routing algorithm in the lower mesh network,and the other is the path that requires optical signals to communicate between clusters through the upper interconnection.Compared with mesh,when the Manhattan distance between communication nodes is too long,the architecture can reduce the number of communication hops through inter-cluster communication,so as to reduce the insertion loss and the accumulated crosstalk noise.In addition,because the connectivity is higher than mesh,the network performance of onocs based on VCmesh is also enhanced.The main contents of this paper are as follows:(1)The basic silicon-based optical devices used to build ONoCs are introduced,and the mathematical formulas of power loss and crosstalk noise of the basic optical switching elements(BOSES)composed of them are given.(2)The design method of VCmesh network structure and length optimized routing protocol(LORP)are proposed.Additionally,the optical circuit switching(OCS)mechanism for ONoCs is introduced.(3)Establish the mathematical analysis models of power loss and crosstalk noise at router level and network level respectively.Numerical simulation shows that VCmeshONoCs has higher communication reliability than mesh-ONoCs,especially in the aspect of minimum laser emission power,VCmesh has obvious advantages.(4)Finally,using OPNET simulation,the end-to-end delay(ETE delay)and network throughput of mesh-ONoCs and VCmesh-ONoCs under different network scales are compared.The results show that VCmesh has better performance in terms of delay and throughput.