Research And Implementation Of NoC Self-similar Traffic Generation Method

Network on Chip(NoC)is a new on-chip communication architecture to solve the communication bottleneck of System on Chip(So C).The performance of NoC is highly dependent on the actual traffic,and the self-similarity is an important characteristic of NoC traffic.It can directly affect the accuracy of NoC traffic modeling and the control of high-speed traffic.To generate the traffic with the characteristic of real network is critical for evaluation and analysis of NoC design.Analysis and comparison of several self similar traffic models used commonly,which based on the fractional Gauss process model is easy to implement,and can more accurately describe the self similarity of traffic.Two methods of fractional Gauss process are realized through the Matlab simulation analysis,which are random midpoint displacement method and fractal Gauss noise method.Simulation results show that the latter is faster and more accurate.To address the problem of FGN based method,less effective in approximating Gaussian power spectrum,a high-order linear fitting method is proposed.The power spectrum of fractal Gaussian noise is divided into two parts:finite and infinite accumulation terms.Using Matlab fitting toolbox cftool to fit the infinite terms of power spectrum,can reduce the amount of calculation and removes of errors caused by approximate substitution in mathematical derivation.Simulation results show that the relative error of the improved method is lower than the formula derivation method in generating self-similar traffic,and the computing speed of the improved method is faster.The NoC self similar traffic generator based on FPGA is designed,which is based on improved self similar traffic generation method.According to the characteristics of the NoC node,the generator can set the parameters of the traffic,including the average rate of traffic,burst,node injection rate,etc..At the same time,the model can also set up the NoC packet format,including the length of the microchip,the number of bits,the source address,the destination address and other parameters,support for multiple working clocks,7-channels output simultaneously.