三维片上网络以其更短的全局互连、更高的封装密度、更小的体积等诸多优势,已引起国内外学术界和产业界的高度重视.对三维片上网络的研究,将直接影响一个国家未来三维集成电路和三维芯片产业的发展,也关系到国家安全.近年来,三维片上网络逐渐成为片上网络研究领域的一个重要方向,已取得了许多研究进展,但仍然存在许多挑战性的课题.对三维片上网络的基本问题作了简介;分析了三维片上网络在国内外的研究现状;讨论了三维片上网络研究中的关键问题,归纳出网络拓扑结构、路由机制、性能评估、通信容错、功耗、映射、测试、交换技术、服务质量、流量控制、资源网络接口等12类研究课题;分类综述了关键问题的研究进展;分析了三维片上网络存在的问题;指出,在三维片上网络拓扑结构方面:个性化拓扑结构设计、仿真平台研究开发、基于新型拓扑结构的三维芯片样片试制以及无线技术的引入等,在路由算法方面:适合3D Torus的路由算法、结合无关路由与自适应路由算法优点的新路由算法、适合各种新型拓扑结构的高效路由算法等,在性能评估方面:永久故障的容错、改进仿真程序增加对物理链路的建模、充分考虑通信的局部性等,在功耗方面:对拓扑结构/映射算法/路由算法和布局进行综合优化、动态和静态控制相结合、更为精确的3D NoC功耗模型等,在映射方面:发热均匀性、动态路由策略下映射评估模型的优化、低功耗映射算法、基于优化算法的组合映射等,都将是三维片上网络未来的重要研究课题.

3D NoC has attracted a lot of attention from both academia and industry with the advantages such as shorter global connection, higher integration density and smaller size. The research on 3D NoCs not only directly affects the development of 3D IC and 3D chip industries but also influences national security. In recent years, 3D NoC has become an important trend in the research of network-on-chip with considerable progress, but many challenges remain. This paper gives a brief introduction of the major issues and reviews the state of arts. It reviews the key problems for the research of 3D NoC in 12 categories including network topology, routing mechanism, performance evaluation, communication fault tolerance, power consumption, mapping, testing, switching technique, QoS, flow control, and resource network interface. It then discusses in detail the research progress and solutions for each type of problems. The problems for network topology include customized topology design for 3D NoC, development of simulation platforms, prototype of 3D NoC based on new topologies and the introduction of wireless. The problems for routing algorithms include new routing algorithm for 3D Torus, new routing algorithms based on the combination of oblivious routing and adaptive routing. The problems for fault tolerance include fault tolerance for permanent errors, adding simulation of the physical link into the original simulation platform, and taking the locality of the communications into consideration. The problems for power consumption include the comprehensive optimization of topology, routing and floorplanning, combination of static and dynamic controls, and power consumption model for 3D NoC with more accuracy. The problems for mapping include balance of heat precipitation, optimization of mapping evaluation model under the dynamic routing strategy, low power mapping algorithms, and mapping combination based on intelligent optimization algorithms. The problems mentioned above all deserve the attention for future research on 3D NoCs.

国家自然科学基金(61272006)