基于虚通道故障粒度划分的3D NoC容错路由器设计

Design of Fault-Tolerant Router for 3D NoC Based on Virtual Channel Fault Granularity Partition

深亚微米工艺下,路由器受制于制造缺陷及运行时的脆弱性,易发生虚通道(virtual channel,VC)永久性故障,从而引起通信故障,影响系统功能和性能.为了能够有效地容忍虚通道故障、保证系统性能及充分利用可用资源,将虚通道故障类型细分为粗粒度故障和细粒度故障,提出SVS(single VC sharing)路由器架构,通过将路由器端口两两分组,组内端口间实现单虚通道共享.当发生虚通道粗粒度故障时,使用组内相邻端口共享虚通道容错.当发生细粒度故障时,根据Slot State Table信息配置虚通道读/写指针的值,从而跳过故障Buffer槽实现容错.在无粗粒度故障情况下,共享虚通道还可用于负载平衡及容忍路由计算模块故障.实验结果表明:较其他已有的虚通道路由器,SVS路由器在3种不同的故障情况下均较大地降低了延时,提高了吞吐量.这表明SVS路由器可有效提高系统可靠性,保证了系统性能,充分利用了可用资源.

Routers become subject to physical manufacture defects and running-time vulnerability in the deep submicron technology,which results in virtual channel permanent faults.The faults affect the performance and functionality of systems and result in communication malfunctions.In order to tolerate virtual channel faults effectively,and to ensure system performance and efficient usage of available resources,the type of failure is subdivided into coarse-grained fault and fine-grained fault,and then we propose the SVS router（single virtual channel sharing router）architecture to achieve a single virtual channel sharing between ports in the same group,which contains two ports in the router.Coarse-grained faults are tolerated by using adjacent ports＇shared virtual channel in the same group.According to the information of Slot State Table,fine-grained faults are tolerated by configuring read/write pointer value to skip fault buffer slots.Also,in the absence of coarse-grained fault condition,shared virtual channel can be used for load balancing and fault tolerance of calculation module.Experimental results demonstrate significant reduction in average packet latency,and improvement in throughput under three different fault conditions compared with other existing virtual channel architectures.It shows that this scheme effectively improves system reliability,ensures system performance and makes full use of the available resources.