LXI仪器系统时钟同步算法分析与实现  

Clock synchronization analysis and implementation in LXI systems

作　　者：吴树奎[1] 王家礼[1] 詹劲松[1] 

机构地区：[1]西安电子科技大学机电工程学院,西安710071

出　　处：《电子测量与仪器学报》2010年第7期605-609,共5页Journal of Electronic Measurement and Instrumentation

摘　　要：在LXIA类和B类仪器系统中,提出系统的同步触发方式,即硬件触发、LAN触发、时间基触发和LXI触发方式,在LXI触发和时间基触发中要求时钟同步精度达到亚微秒级。为了满足这个同步精度,本文对IEEE1588精密时钟同步机制和算法进行了研究,分析了LXI仪器系统中影响同步的因素,在同步算法中的时间戳信息使用FPGA对PTP数据包采用时间戳的物理层识别和截取,减小了网络抖动,为了解决主从时钟的晶振的偏移提出了采用本地时钟晶振补偿算法进行同步补偿。使用LXI测试平台进行试验验证,从测试数据可看出主从时钟同步精度达到30ns,试验结果表明通过很大程度提高了同步精度,满足了LXIA类和B类仪器时钟同步的要求。In LXI A and B class of instrument systems,the required system triggers model is hardware trigger,LXI trigger,LAN trigger,and Time-based trigger.In LXI trigger and Time-base trigger,clock synchronization precision is required to achieve sub-microsecond level.In order to satisfy synchronization precision,the IEEE1588 precision clock synchronization mechanism and algorithm are researched,the factors of affecting synchronization are analyzed.In synchronization algorithm,in PHY take FPGA to capture PTP message＇s time stamps to ruduce the jitter,take local clock crystal oscillator compensation to reduce bias.In Intel IXP 465 measurment platform execute experimentation.From test data,master clock and slaver clock Synchronization resolution is 30 ns.By the measurement results,the synchronization precision is improved,and clock synchronization requirement for LXI A and B class instrument is satisfied.

关 键 词：LXI IEEE1588 时钟同步 晶振补偿 

分 类 号：TN915[电子电信—通信与信息系统]