Research On Congestion Avoidance Scheme And Reconfigurable Network Architecture In WiNoC

To solve the problem of high latency and high power consumption of long distance multi-hop wired links in traditional No C(Network-on-Chip),wireless communication technology is used on the chip.However,the arrangement of wireless transceivers requires a large amount of on-chip resources,so only a small number of on-chip routers can be equipped with wireless interfaces.Packets transmitting through wireless channel must be routed to the wireless interface,which results in WiNoC confronting with more serious congestion problems than traditional NOC.In addition,due to the principle of spatial and temporal locality during task executions,only a few remote high-frequency communication pairs on the chip need to use wireless links at the same time.However,in the traditional scheme,the allocation rules of wireless interfaces are fixed and cannot be changed with the change of on-chip traffic,which is lack of flexibility.For the above concerns,this dissertation designs an efficient congestion avoidance scheme and a reconfigurable wireless interface for WiNoC.The main work of this dissertation is as follows:1)Balancing the traffic load of wired/wireless links in view of the congestion problem of wireless nodes in WiNoC.In this dissertation,we propose and design a Pb SA(Priority-based Switch Allocator),which routes the wireless packets with higher Priority to the wireless nodes.Combined with Pb SA,the CARA(Congestion-aware Routing Algorithm)is proposed.The Algorithm effectively balances the load of wired/wireless links and avoids deadlock,thus improving the routing efficiency of packets in the network.In addition,this dissertation also proposes an effective virtual channel partition method,which not only reduces the hardware complexity of Pb SA implementation,but also alleviates the impact on the whole network when wireless nodes are congested.Experimental results show that although the scheme in this dissertation introduces small area and power consumption overhead,it has good traffic adaptive characteristics,so that the average transmission delay of packets is reduced and the saturation throughput of the network is improved when packet injection rate varies.2)The flexibility of wireless interfaces in WiNoC.Based on the principle of spatial and temporal locality during task executions,this dissertation proposes and designs a traffic adaptive reconfigurable wireless interface in WiNoC.Traffic adaptability is mainly reflected in that the wireless interface can use MUX to reconstruct its links to routers on other chips according to the historical traffic state,so as to improve the wireless utilization efficiency.In addition,this dissertation reduces the performance overhead caused by refactoring by designing refactoring rules and allocation modules.The experiment results show that the proposed scheme improves the performance of latency and throughput compared with the fixed wireless interface under the 64-core WiNoC network architecture,only increases the power consumption and area overhead by about 0.452%and 0.08% respectively.