如何分享Spartan 3E DCM时钟输入频率变化信息

数据表显示，Spartan3E DCM可以处理高达1nSec的输入时钟边沿时序变化，前提是这种情况发生在“数百万”周期内。
但是，我有一个应用程序，在每小时10ppm的区域内频率变化可能很慢，总共50pmm，我找不到有关DCM是否会容忍这一点的任何信息。
有没有人对此有任何了解，他们愿意分享或了解任何其他信息来源？
谢谢你的帮助。
罗伯特



以下为原文

The data sheet says that the Spartan3E  DCMs can cope with up to 1nSec of input clock edge timing variation provided this occurs over "millions" of cycles. However, I have an application where there may be slow frequency changes in the region of 10ppm per hour up to a total of 50pmm and I can't find any information about whether the DCMs wouldl tolerate this. Does anyone have any knowledge on this that they are willing to share or know of any source of additional information?

Thanks for any help.

Robert