Hardware Design Of High Capacity Data Acquisition Module Based On PXIe

With the development of virtual instrument technology, PXIe bus has combined Compact PCIe bus’ s high-band data transmission characteristic with different instrument modules’ precision synchronization feature. It will become a new generation of instrument test bus. It is the data acquisition module based on PXIe with large on-board storage capacity that has been widely used in various instrument test fields owing to fast data throughput and large on-board storage capacity. At present, many foreign instrument manufacturers have developed high-capacity data acquisition modules based PXIe bus, but China is still in its infancy. Therefore, it’s necessary to develop a PXIe data acquisition module at home.In this paper, According to my master’s degree project that PXIe DSO(Digital Storage Oscilloscope) module with large on-board storage memory, and concentrating on the virtual instrument bus technology development and large capacity data storage technology. Mainly conducted in-depth research in the following aspects:(1) Data acquisition circuit design. It mainly translates an analog signal into its digital signal in order to obtain corresponding digital information.(2) Mass data storage circuit design. This article will mainly discuss the realization of DDR2 SDRAM controller’s four schemes, combine with the difficulty of mass data storage circuit’s development and design costs, and ultimately determine the use of DDR2 SDRAM controller IP(Intellectual Property) core in FPGA to achieve the high-capacity data storage control.(3) PXIe interface circuit design. On the basis of Compact PCIe specification R1.0,PXIe hardware specification 1.0, PCIe base specification 3.0 and PCIe card basic electrical and mechanical specifications 1.1. Discussed in depth PCIe four kinds of implementation, and summarized their advantages and disadvantages. Ultimately determining the use of specific integrated chip PEX8311 to realize PCIe protocol. In addition, in-depth study of additional synchronization feature on PXIe backplane.After tested, PXIe data acquisition module has achieved to data acquisition base functions including acquisition, storage and transmission. The PXIe data acquisition module can achive maximum real-time sampling rate up to 2GS/s, on-board memory up to 256 Mpts and the PXIe module can normally work in PCIe x1 protocol mode. Datatransfer rate can achieve up to approximately 200MB/s. So it has given full play to the advantage of PXIe’s high-speed data transmission.