基于眼图测试的USB接口链路故障定位方法

A Fault Location Method of USB Link Based on Eye Diagram Test

主要介绍基于CPCI协议的某设备USB触摸操作屏偶然出现运行失灵,进行故障分析时未复现而无法定位,通过对系统USB接口链路分析后进行眼图测试,快速定位故障的过程。测试过程中使用的是TEK公司的DSA71604B型示波器和配套的USB夹具,通过关键USB接口点的眼图得到信号质量变化,利用信号衰减对故障定位,提高了问题定位的效率。该测试对于USB2.0机理、眼图及信号完整性的探讨,对后续模块故障定位具有参考意义。

This paper describes a type of USB touch screen operation run occasional failure,as failure analysis does not reproduce and can not be targeted,through the USB interface link analysis system and eye diagram test,and locate the fault quickly.Using the TEK DSA71604B oscilloscope and supporting USB fixtures,getting signal quality changes through the eye diagram of key interface point,using the signal attenuation to locate the fault,improved the efficiency of positioning problem.