The Research And Realization Of Clock Synchronization System In Fiber Channel Network Switch

As a new generation of high performance network,the fiber channel network is very suitable for the system with high requirement of real-time data transmission because of its high bandwidth,low delay and high reliability.The distributed real-time systems,such as electric power,aviation,military,railway dispatching command and so on,all have accurate time requirements.If the systems' command and execution time have deviation,it may cause major accidents.The precise time sign is more and more important in the network.The purpose of the clock synchronization system is to transmit time to each node accurately in the network and to make each terminal have the unified time information.If the network fails,it is possible to research the order of each node's event in the network and to easily debug the whole communication network according to the log file that contains the time information.In this thesis,to meet the requirements of the clock synchronization and the performance of fiber channel network,a high precision and low delay clock synchronization system in optical fiber channel network is designed and implemented.In this thesis,the characteristics of fiber channel network,topology,network layer,frame format and other contents are studied.All of them provide a theoretical basis for realizing clock synchronization in fiber channel network.On this basis,a new clock synchronization system is designed,using the Verilog hardware description language to realize the function of clock synchronization in the multiple port switch chip of fiber channel.Then the clock synchronization circuit is simulated in the virtual platform through giving the waveform of simulation results to ensure the accuracy of the design function.In this thesis,high precision and low delay clock synchronization system in fiber channel network switch chip is designed and implemented.It can meet the requirements of the clock synchronization and performance of the fiber channel network and provide accurate clock information for the real-time transmission and exchange of data.It specifically used the method of clock synchronization primitives as defined in the Fiber Channel protocol.And the clock synchronization accuracy of microsecond in the each node of the fiber channel network can be successfully reached.The software simply configures the clock synchronization circuit,such as the clock synchronization enabled,the synchronization cycle and so on.The core clock synchronization function,such as the transmission,reception and resolution of clock synchronization primitives with time information,is completed by hardware.The specific implementation method is that the clock synchronization primitives replace three consecutive idle primitives between the frames and then send to the fiber channel data link.At the same time,it finds a practical solution to the collision problem of multiple clocks in the fiber channel network.And it integrates the design clock circuit in the form of IP into multiple ports' devices to realize high clock synchronization precision in fiber channel network.The clock synchronization system designed in this thesis can provide a unified time basis for the construction and debugging of fiber channel network and accelerate the promotion and application of fiber channel technology.