Design And Implementation Of A Multi-channel Measurement System Based On FPGA And EMMC

When a hypersonic vehicle is flying at high speed,its boundary layer flow field changes in a complex manner,which requires the construction of an array distributed multi-channel measurement system to obtain various parameters during the flight of the vehicle and provide data support for subsequent theoretical analysis.Most of the traditional measurement systems use NAND FLASH as the storage medium,which has many defects such as complex control,low integration,slow storage speed and small storage capacity.To address the above problems,this paper designs a multi-channel measurement system based on FPGA and e MMC.e MMC is used as the solid-state storage medium,which has the advantages of simple control,high integration,fast storage speed and large storage capacity,solving the defects of traditional measurement systems.The multi-channel measurement system designed in this paper is used to acquire temperature,pressure and other parameters of the boundary layer flow field of a hypersonic vehicle.The system is capable of synchronously acquiring and storing multiple analogue signals,using an FPGA as the main controller,selecting a multi-channel synchronous sampling ADC to achieve synchronous acquisition of multiple analogue signals,equipping a DDR3 SDRAM chip as a high-speed cache unit,selecting an e MMC memory chip as a solidstate storage medium to achieve high-speed and large-capacity storage of data,and transferring the stored data to the host computer via a Gigabit Ethernet interface.Firstly,this paper conducts an in-depth study of the system key technology theory e MMC5.1 protocol,and designs the overall system scheme according to the requirements and indicators of the measurement system.Secondly,the design of the system hardware circuit is completed,mainly including the power supply circuit,FPGA core circuit,ADC acquisition circuit,DDR3 cache circuit,e MMC storage circuit and Ethernet transmission circuit.Then,the design of the system software logic was completed,mainly including the data acquisition module,DDR3 cache module,e MMC storage module and Ethernet transmission module.The design of the e MMC controller is the focus and difficulty of the whole system logic design,which mainly includes four parts: clock management,initialisation,command interface and data interface,realising the initialisation,data reading and writing,data erasing and other operations of the e MMC memory chip.Finally,an experimental test plan was designed,an experimental test platform was built,and detailed functional and performance tests were conducted on the system using an online logic analyser and various upper computer software.The experimental test results showed that all modules of the system functioned normally,and the maximum storage speed could reach 160MB/s with a storage capacity of 128 GB,meeting the design index requirements.