The Research On Reliability And Routing Method For Fault-tolerant In Network On Chip

With the continuous development of fabrication technology of the integrated circuit, the number of transistors integrated on a single chip is increasing and has exceeded billions of transistors. Therefore, more and more IP cores can be integrated on a chip. With the increasing of the number of the IP cores on a chip, the traditional System-on-Chip (SoC) based on bus structure has many problems such as the poor extendibility, low communication efficiency due to non-parallel communication, and power consumption and area problem caused by the synchronization of global clock. All these problems are insurmountable obstacles for the SoC. Therefore, In order to solve these problems, Network-on-Chip (NoC), a new interconnected architecture was proposed by some experts. NoC could solve the problems in traditional SoC and use the communication mechanism of Globally Asynchronous Locally Synchronous (GALS).So NoC becomes the new architecture for the process of nanotechnology.In this thesis, the research of NoC based on 2D-Mesh structure is focused on. A kind of method of reconfigurable routing algorithm for fault-tolerant and a kind of method for improving reliability of NoC were proposed which direct the 2D-Mesh NoC.The main work is as follows:(1) This thesis introduced the technical background of NoC, the key issues and the current scientific research situation of NoC. In addition, related knowledge, such as 2D-Mesh structure, exchange mechanisms, routing algorithms, fault- tolerant technology for router and so on in NoC, are introduced.(2) For the fault of the router in NoC, a reconfiguration-based fault-tolerant method for NoC is presented. In the process of the communication, the present faulty routers will affect the whole system communication. We set up a Status Register for each router which is used for marking the status of the adjacent nodes. In the process of communication, with the help of the information provided by the register, data packets will bypass faulty routers and go to the proper destination nodes. The experimental results show that this method could achieve the fault-tolerant function and guarantee the whole communication, which can reduce latency of data transmission. (3) According to the characteristic of 2D-Mesh NoC, to solve the invalidated communication affected by the neighbor faulty routers, this thesis proposes a novel method which is used for improving communication reliability. In the NoC system, the fault of the router makes the router useless, and influences the communication with the IP cores. With the help of the communication matrix, IP cores choose adjacent nodes and create links with these nodes before communication starts. When the local routers are faulty, according to the state of the routing, the algorithm chooses optimal redundant routers for connecting. The experimental results show that this method could improve communication reliability of NoC and achieve lower latency.