Cpci Bus-based Digital Graphics, I / O Design,

Digital graphics I/O module is a very important test module in a data field test, which can be smiple digital signal generator and logic analyzer for data transmission and data acquisition. Digital I/O module can send test signals to the DUT and collect feedback data from DUT. The subject design digital graphics I/O module based on CPCI bus is used to build the data field test platform.The scheme of CPCI interface chip + FPGA + SRAM + two-way drive chip hardware frame structure has been adopted to achieve the design of digital I/O module .In the CPCI bus interface design, PLX corporation's PCI interface chip PLX9030 has been used to communicate with CPCI bus,which reduce the entire reserach cycle. For the digital graphics I/O module on CPCI bus ,the key part is lain in the external SRAM's reading and writing operation. This paper focuses on, the digital graphics I/O module hardware structures, implement the main control logic of the whole system with programmable logic device,finally realize the external multi-chip SRAM's various modes of reading and writing.As the development of data field test theory and technology, which have put forward many new requirements for test instruments. Whether the storage depth of the module, or sending and receiving data rates have greatly improved. The digital graphics I/O module on CPCI bus have 48-channel independent input and output, whose memory depth is 512Kbit / per channel, and the fastest data rates up to 50MHz. A variety of optional data transmission mode, which can be single, periodic, discrete-level data , and you can choose to send by the software. The tester can choose data acquisition modules flexibly according to testing requirements,which can be channel trigger or random trigger modes. Software and hardware test results show that the design of digital graphics I/O modules, meet the task demands, can easily be applied to the data field test platform.