External Mixed Signal Analyzer Oscilloscope Module Design

With the development of electronic technology, the function of simple digital storyge oscillograph or logic analyzer in the field of test data can not fully meet the demand, so mixed signal analysis is the development trend of test tool in the field of test data. Considering the developing trend of the mixed signal analyzer in our country, we designed the portable the mixed signal analyzer based on USB (Universal Serial Bus) with maximum 500MHz timing analysis rate. With utilization of computer, this mixed signal analyzer improved the performance of data analysis, and lowers the cost of the instrument.This dissertation describes the basic theory of the mixed signal analyzer. It presents the hardware circuit of the mixed signal analyzer as well as the design of the interface circuit of the USB.This design use the advanced A/D convert chip and FPGA device, and realize high-speed data sample and complex functions liking memory control and trigger function. We use the UART to reduce the frequency of posterior data process circuit in the design of high-speed sample .And it use the double-memory structure in the data storage design. It realize the single trigger of oscillograph and synchronous trigger of block of logic analysis.The new points of this design are synchronous trigger of the block of oscillograph and block of logic. And the important part of the realization of the function of the system is the project of UART and double-memory structure. With the reduce of device costs and the appearance of the high performance of device, to use this design can produce production of higher sampling rate.In the design of the USB interface, main performance of USB protocol is introduced. And it also researchs the USB interface chip and the connection with data acquisition circuit. And the design of the firmware and drivers as well as the waveform of the GPIF is mainly studied. Then it presents an in-system programming method which makes the upgrading of the system easier. .These test results indicate that this logic analyzer has good capability of logic analysis and nice data transmission with USB interface.So it can meet the requirement of hign-speed signal analysis.