Design Of VXIbus Scan A/D Module With Large Capacity Memony

VXIbus C size scanning A/D converter module is one of the important modules for integrating aviation automatic measurement systems. The Original Scanning-A/D-Converter Module doesn't have functions of programmable gains, automatic calibrating, optional per-channel signal conditioning; and its scanning speed is low, measurement precision is poor. It is necessary to redesign this module, to meet the practual requirement.The module uses FPGA technology to control the VXI interface and the A/D converter and the PGA.It deals with the problem of the order scanning and the random scanning. Interruption associate with large capacity FIFO is used to improve the capability of channels parallel communication. High speed and big capacity DRAM is used to solve the problem of huge throughput capacity. Use high speed, large addressing space and float-point DSP to deal with the problem of too many channels and data architecture complex and high data transfers speed. With the technique of hardware paste, multiple children boards can be combined to provide proper signal conditioning for a wide variety of input signals. A high performance D/A converter is adopted to accomplish the programmable gain adjusting. The module also provides on-board reference sources that can be selected as input by the relay in every channel and stored in the module to compensate for system offsets, improving the measurement precision; n the design of software, program the DSP software to realize different buses work at one time. The drivers and panels, which accord with the VXI plug&play specification are developed based on the Labwindows/CVI, and complete the data transmission between the module and the computer.As can be seen from actual test, the VXI-aviation serial communication module is designed in reason and satisfies all the performance.