The Research And Development Of Mixed Signal Oscilloscope Serial Bus Protocol Analysis

With the rapid development and extrensive application of serial bus technology, to develop and research the digital oscilloscope that having both digital and analog channels has become an inevitable Therefore, Mixed signal oscilloscope then arised at the historic moment. At present, the mixed signal oscilloscope serial bus protocol analysis technology is still relatively backward compared with other countries.Aiming at this situation, the article mainly completed the software development of USB and Ethernet protocol analysis on the basis of mixed signal oscilloscope. The whole software system based on industrial PC and Windows. It mainly divided into the upper machine, bus acquisition data processing and the bus protocol analysis modules.The main contents are following:1. Firstly, according to the paper's mission requirements and functional parameters, it expounds the overall design scheme of the system, presents a detailed design scheme of every module function and the difficulty in the design of the software key analysis.2. With the division USB and Ethernet, in the PC implementation modules, it includes each menu control, each window Settings and waveform display design.3. In the bus acquisition data processing.module, in USB bus, it includes differential signal into a single-ended signal, extracting effective bits, NRZI decoding and removal of stuffing bits. In Ethernet, it includes threshold determination, differential signal into a single-ended signal, Manchester decoding and eight bis merge to one byte.4. In the bus protocol analysis module, it realizes the digital tag, digital waveform, event list and event search function design. In event search, it uses the BM algorithm for the implement of long tag event.5. It summarizes the double buffering graphics technology in PC Design, problems and solutions in debugging. It expounds the achievement of key thread, acquisition thread and data processing thread in detail.Finally, it tests and verifies each functional module. Verification results show that, the bus decoding labels, event list, event search functions have stable operating results and reach the set performance indicators.