| Mixed signal oscilloscope is a new type of oscilloscope integrating features from digital storage oscilloscope and logic analyzer.It offers numerous advantages,such as a large number of channels and the ability to analyze both analog and digital signals simultaneously with exceptional efficiency.As a result,it can meet the test requirements of complex signals in high-speed systems and has a wide range of application scenarios in the modern test field.The signals in contemporary electronic equipment tend to be high-speed and complex,leading to an increasing demand for phase analysis between multiple high-speed signals.The accurate analysis of the phase between signals puts forward higher requirements on the synchronization accuracy between the channels of the oscilloscope.Additionally,instances of system malfunction due to occasional abnormal signal events are becoming more prevalent.The ability of an oscilloscope to capture occasional anomalies is critical to solving such problems.This thesis focuses on the technical aspects related to synchronous acquisition and3 D mapping of multi-channel mixed signal oscilloscope,designed and implemented a multi-channel synchronization scheme and a high waveform capture rate acquisition system.The main work is as follows:1.The FPGA logic architecture of the system is designed according to the indicators of multi-channel mixed signal oscilloscope,considering the principle of oscilloscope and the special demands of some key indicators.Subsequently,the entire system is implemented.2.To achieve high-precision synchronization between channels,a sampling clock synchronization generation circuit scheme between multiple acquisition boards is designed by cascading multistage clock chips in a clock tree structure.This design fulfills the clock and synchronization signal requirements of multi-chip ADC devices.Based on the deterministic delay characteristic of JESD204 interface,the synchronization issue between multiple ADC devices is solved.The mixed signal trigger system is improved by separating the trigger parameters in time domain and digital domain to realize the delay correction between analog and digital channels.3.To enhance the waveform capture rate of the system and increase the ability to capture low probability events in complex signals,a high waveform capture rate acquisition system is constructed based on the principle of 3D mapping.Aiming at the issue that the efficiency of inter-board transmission affects the waveform capture rate,an inter-board alternating transmission system based on Ser Des high-speed serial transmission technology is designed and implemented.The parallel cache and mapping processing submodule of the 3D mapping module are redesigned to address the complex connection between the RAM resource and the related control unit,resulting in the implementation of a high-performance 3D mapping system.4.To solve the issues of insufficient layering and unclear information feedback of monochrome 3D waveform display,a 3D mapping cross-color display scheme based on HSV color model is proposed.The probability information can be displayed more intuitively through different probabilities corresponding to different hues.Furthermore,the probability matrix is exported without compression by using the characteristic of GPU coloring to increase the amount of data sent back to the host machine.Utilizing the multi-channel mixed signal oscilloscope platform,the thesis successfully achieves the specified requirements that synchronization accuracy between6 analog channels is ±100ps,and synchronization accuracy between analog and digital channels is ±2ns.In 3D mapping mode,waveform capture rate of not less than850,000wfms/s is achieved,accompanied by various cross-color display functionalities. |
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