Design Of Optical Fiber Data Transmission Circuit Based On FPGA+DSP

With the innovation of information transmission technology and the update of aerospace technology,the total amount of data in the system is larger and larger,the bandwidth demand and speed requirement are getting higher and higher,and there are more and more interconnected devices with different interfaces,which limits the efficiency of data transmission.The traditional transmission mode can no longer meet the requirements of high-speed data transmission,and optical fiber transmission circuit has become one of the key technical applications of scientific research institutes and military enterprises due to the advantages of large capacity,wide frequency band,and strong anti-interference.The optical fiber data transmission circuit belongs to the hardware platform of the external system equivalent,and the high reliability transmission can ensure the comprehensive performance test of aircraft in the development and use stages.According to the requirements of project design and circuit test,the optical fiber data transmission circuit based on FPGA+DSP was designed,and the control logic conforms to FC-AE-1553 bus standard.The analog signal source was sent and received to the test equipment through optoelectronic modules,optical interface converters and multi-mode optical fibers,and the transmission rate meets 2.5Gbps;Data processing was performed in real time through the asynchronous communication EMIF bus between FPGA and DSP,and the transmission rate is 20MB/s in the case of 16-bit data bus or 40MB/s in the case of 32-bit data bus;The configuration instructions and data information communicated with the computer through Gigabit Ethernet,and the transmission rate is up to 400Mbps;Four RS-422 interfaces with transmission rate of2Mb/s were designed to provide flexible connectivity to other test equipment.The circuit adopt the principle of modular design,and carried out hardware design for FPGA system,DSP system,photoelectric conversion circuit,Gigabit Ethernet,RS-422 interface,configuration power supply,etc.At the same time,the logic design of GTX,EMIF,Ethernet and RS-422 transmission was carried out.Aiming at communication difficulties,the dual redundant transceiver and NC/NT functions were used to realize data transmission.Finally,the circuit test platform was built to verify the functions of the optical fiber data transmission circuit and realize the function of the external system equivalent.The test results show that the circuit works stably,the optical signal transmitted to the measuring equipment meets the rate of 2.5Gbps,and there is no phenomenon of missed acquisition,missed transmission,repeated acquisition and repeated transmission.