一种高精度的系统时间同步方案

A Synchronization Solution of High Precision System Time

针对嵌入式系统中时间同步的需要,结合智能变电站中过程层IED的实际技术要求,提出了一种具体的系统时间同步方案。通过FPGA和CPU的相互配合,以及对Power PC中时间基寄存器的使用,将整个同步过程按时间刻度分为秒级同步和纳秒级调整两个部分,即保证了时间信息整数部分的正确性,又满足了小数部分的精度要求。并通过专门的测试环境,计算出了该同步方案的精度范围,结果表明,该同步方案可完全满足过程层IED的技术指标,具有一定的推广价值。

Aiming at the demands of time synchronization in embedded system,combined with the actual technical requirements for process-level IED of smart substation,a solution of concrete system time synchronization is presented in this paper.Through the mutual cooperation of FPGA and CPU both with the use for time base register of Power PC,the synchronization process is divided into the synchronization of second level and the adjustment of nanosecond level.This design is to ensure the correctness of the integer part of the timestamp,but also meet the accuracy requirements of the fractional part.The accuracy of the scope of this synchronization scheme is calculated through a dedicated test environment.