【作者】 张琛；

【导师】 叶芃；

【作者基本信息】 电子科技大学 ， 仪器科学与技术， 2023， 硕士

【摘要】 混合信号示波器是一种在数字存储示波器和逻辑分析仪的基础上发展而来的新型示波器,具有通道数量多、模数信号可同时进行分析、使用效率高等优点。能够满足高速系统中复杂信号的测试需求,在现代测试领域中具有广泛应用场景。现代电子设备中的信号呈高速、复杂化趋势,对多路高速信号间相位的分析需求逐渐增多。信号间相位的准确分析对示波器各通道间的同步精度提出了较高要求。同时,信号中的偶发异常事件导致系统无法正常工作的情况愈发多见,示波器对偶发异常事件的捕获能力对此类问题的解决至关重要。本文对多通道混合示波器的同步采集和三维映射相关技术问题开展研究,设计并实现了一种多通道同步方案和高波形捕获率采集系统,主要工作内容如下:1、根据多通道混合示波器指标,结合示波器工作原理及部分关键指标的特殊需求,对系统内的FPGA逻辑架构进行设计并完成整机系统的实现。2、为实现通道间的高精度同步,通过多个时钟芯片基于时钟树结构级联的方式,设计了多采集板卡间的采样时钟同步产生电路方案,满足多片ADC器件对时钟和同步信号的需求;基于JESD204接口的确定性延迟特性,解决了多片ADC间的同步问题;改进混合触发系统,将模拟通道与数字通道的触发参数分离,实现模拟通道和数字通道间的延迟校正。3、为提高系统的波形捕获率,增加系统捕获复杂信号中低概率事件的能力,基于三维映射原理,搭建高波形捕获率采集系统。针对板间传输效率影响系统波形捕获率的问题,设计并实现了基于Ser Des高速串行传输技术的板间交替传输系统;针对三维映射模块的底层RAM资源与相关控制单元连接复杂的问题,重新设计三维映射并行缓存与映射处理模块,实现了高性能的三维映射系统。4、为解决单色系三维波形显示层次感不足和信息反馈不明确的问题,基于HSV色彩模型设计并实现了三维映射跨色系的显示方案。通过不同概率对应不同色相的方式,更直观的展示概率信息。同时利用GPU对概率矩阵着色的特性,增加了回传至上位机的数据量,实现了概率矩阵的无压缩导出。本文基于多通道混合示波器平台,成功实现了6个模拟通道间同步精度在±100ps以内,模拟和数字通道间同步精度在±2ns以内的指标。在三维映射模式下,达到了不低于850,000wfms/s的波形捕获率,同时实现了多种跨色系显示功能。更多还原

【Abstract】 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.更多还原