摘要
集成电路的不断发展使得片上系统遇到了不可逾越的瓶颈问题,片上网络因其具有良好的可扩展性、较高的通信效率和可靠性等优势成为了一种新型的互连架构,被研究者们广泛研究.路由器是片上网络中的关键部件,主要负责数据包的存储转发,影响着网络的整体性能,故对路由器的容错设计显得尤为重要.而路由器中缓冲区所占的面积较大,且常见的缓冲区容错方案都可能会产生头阻塞问题,因此需要设计一种容错路由器架构,既可以解决头阻塞问题,又能实现缓冲区容错.该文提出一种相邻虚通道循环共享的VOQ容错路由器设计,可以有效地容忍虚通道故障,在网络拥塞时能最大程度的保证缓冲区的利用率,且在路由器内部虚通道均故障时依旧可以保证整个网络的连通性.在基准VOQ路由器的基础上,该文通过增加多个多路选择器和数据分配器来实现相邻虚通道的共享,增加旁路总线来保证即使输入端口内部虚通道均故障,路由器依旧可用.当数据包所要发往的虚通道故障或者拥塞时,通过借用相邻虚通道或旁路来实现数据包的存储转发,达到了容错的目的,提升网络性能.同时,该文设计了一种基于双向队列的FIFO控制器,通过两套读写指针实现对借用虚通道数据包和非借用虚通道数据包的读写操作.双向队列的设计,保证了数据包在输出时依旧持有VOQ特性,这是绝大多数的缓冲区容错方案所没有的.实验结果表明,在无故障发生时,该文方案较VOQ路由器和multiple VOQ路由器而言平均延时有所降低,吞吐率有所提高;在故障发生时,该文方案的相邻VC因为可以借用,故较VOQ路由器和multiple VOQ路由器,平均延时分别降低了32.3%和23.3%,吞吐率也有所提高.该文方案没有增加额外的FIFO开销,硬件开销上因为双向队列和BIST检测模块的设计较参考文献方案有所增加,但是相对于其达到的性能而
The continuous development of integrated circuit makes the system-on-chip encounter insurmountable bottleneck problems.Because of its advantages of scalability,high efficiency and reliability of communication,Network-on-Chip（NoC）is becoming a new kind of interconnection architecture and widely studied by the researchers.The router,as a critical component in NoC,ismainly in charge of the packet store-and-forward,which affects the performance of the whole system.Thus,it is especially important to propose a fault-tolerant scheme for the router.Nevertheless,buffer accounts for a large area in the router and traditional fault-tolerant methods for the buffer may lead to the head of blocking（HoL）.Hence,it is necessary to design a fault-tolerant architecture,which can not only avoid the HoL but also achieve fault-tolerance.In this paper,we present the design of virtual output queue（VOQ）fault tolerant router which supports loop sharing of adjacent virtual channels.The proposed fault-tolerant design can tolerate fault buffers effectively,and ensure the buffer utilization at the most extent when congestion occurs in the network,and even guarantee that the connectivity of the entire network in the case of all the input virtual channels breaking down.On the basis of the traditional VOQ router,this paper obtains the loop sharing of adjacent virtual channels by adding a number of multiplexers and de-multiplexers.At the same time,extra bypass buses can guarantee that the router can still route packets in the case of all the input virtual channels fault.When a fault or congestion arises in the virtual channel packets will be sent to,the router could transfer the packets by the adjacent virtual channels or bypass buses,which achieves fault-tolerance and promotes the system performance.Meanwhile,this paper designs a FIFO controller based on a double-ended queue,in which two sets of read/write pointers read or write packets no matter which virtual channels they are stored in.The design of the double-ended queue assures t
出处
《计算机学报》
EI
CSCD
北大核心
2016年第6期1135-1146,共12页
Chinese Journal of Computers
基金
国家自然科学基金(61474036
61371025
61274036)
安徽省自然科学基金(1508085MF117)资助
关键词
片上网络
容错路由器
VOQ
虚通道共享
双向队列
Network-on-Chip
fault-tolerant router
virtual output queue
virtual channel sharing
double-ended queue
