Design And Implementation Of Long-distance High-speed Data Transmission System Based On ZYNQ

At present,the performance of aircraft in China’s aerospace field and the complexity of its stand-alone equipment have increased rapidly,and higher requirements have been put forward for the transmission distance,transmission speed and equipment integration of the ground transmission system that is tested with it.In view of this application requirement,this paper relies on the "A Terrestrial Data Transmission System" development project to design a system with long-distance high-speed data transmission function based on ZYNQ（Zynq-7000 All Programmable So C）,and the main work is as follows:1.In the hardware circuit design of the data transmission system,in view of the problem that the components in the system require many types of voltages and ZYNQ have strict requirements for the power-up sequence,the combination of DC/DC and LDO（Low-Dropout Voltage Regulators）is adopted in the design of the power supply unit,and the thermal design is carried out for the serious problem of LDO heating;the design requirements for improving the integration of the system are used.In the design of the control unit,the single-chip ZYNQ replaces the traditional " processor+FPGA" complex architecture,and builds a minimum system around ZYNQ;for the design requirements of long-distance transmission,the photoelectric conversion module method is used in the design of the external interface unit to achieve long-distance transmission,and the hardware circuit of the Gigabit Ethernet and SRIO（Serial Rapid IO）interface is designed for the design requirements of high-speed transmission,in order to improve the reliability of data transmission.The influencing factors of interface signal integrity are analyzed and suppressive measures are proposed;The hardware circuit of the data transmission system is designed,the combination of DC/DC and LDO（Low-Dropout Voltage Regulators）is adopted in the design of the power supply unit,and the heat dissipation measures are taken in the PCB and structural design for the serious problem of LDO heat generation;in the design of the control unit,based on the design idea of improving the integration of the equipment,the traditional "ARM+FPGA" architecture is replaced by a single-chip ZYNQ.In the design of the external interface unit,the circuit design of RS-422 interface,Gigabit Ethernet interface and SRIO interface to achieve long-distance high-speed data transmission through photoelectric conversion module is introduced in detail,and the influencing factors of interface signal integrity are analyzed and suppressed.2.In the software logic design of the data transmission system,the ZYNQ software and hardware co-programming method is adopted,and the UART serial transmission protocol with odd check bit is realized on the PL side for the requirements of uploading instructions with telemetry equipment;the UDP protocol with automatic retransmission function is realized on the PL side for the design requirements of high-speed and reliable data transmission with the acquisition and editing controller;and the Rapid IO transmission protocol is realized on the PL side for high-speed transmission with the memory test bench In the communication design with the host computer,the Lwip protocol stack is used to achieve high reliability of the standard TCP protocol on the PS side;3.Build a closed-loop test platform,through multiple large data volume tests,the high-speed data transmission system can complete the zero-miss code communication of115.2kbps ±3% through the RS-422 optical interface with the telemetry equipment at a transmission distance of 5km,and achieve zero frame loss and zero error transmission of645 Mbps through the Gigabit Ethernet optical interface with the acquisition and editing controller at a transmission distance of 5km.With the memory test bench at a transmission distance of 10 km,the 444 Mbps zero frame loss and zero error data transmission is realized through the SRIO optical interface.