基于ZYNQ的PTP授时精度测量方法与实现

A method and implementation of PTP timing accuracy measurement based on ZYNQ

针对PTP授时精度测量存在的困难,提出在ZYNQ SOC上用μCOS操作系统和LWIP协议栈,来实现PTP授时精度测量。该方法通过接收卫星导航系统信号,得到准确的系统时间和时钟源差,利用硬件将系统时间同步至ZYNQ的纳秒计数器。利用ZYNQ EMAC接口获取PTP收发帧的观测时间,并利用源差值实现对测量时间的补偿,最终得到准确的时间戳,进而实现对待测PTP主时钟授时精度测量。经实际测试,利用该方法对PTP时钟进行测量,能够获得优于10 ns的测量精度。

Aiming at the difficulties of PTP timing accuracy measurement,this paper puts forward usingμCOS operating system and LWIP protocol stack on ZYNQ SOC to realize PTP timing accuracy measurement.Accurate system time and clock source difference are obtained by receiving GNSS signals,and the system time is synchronized to the nanosecond counter of ZYNQ by hardware.The ZYNQ EMAC interface is used to acquire the observation time of PTP frames,and the source difference is used to compensate the measurement time.Finally,an accurate time stamps are obtained,which can be used to measure the timing accuracy of the PTP master clock.The test results show that using this method to measure PTP clock,the measurement accuracy is better than 10 ns.