AR# 11041

Virtex/E/II, DLL - Is there a limit to the total delay of the feedback path to CLKFB? (CLKFB_DELAY_VAR_EXT)

描述

Is there a limit to the total delay of the feedback path? 

 

If I wish to align internal and board clock, is there a guideline regarding how much delay the CLKDLL/DCM can withstand?

解决方案

There is no limit on the total delay of the feedback path, but there is a limit on how much the delay of the feedback path can vary across environmental conditions. This is specified for Virtex-II as CLKFB_DELAY_VAR_EXT= +/- 1ns. 

 

(This value also applies for Virtex and Virtex-E.)

AR# 11041
日期 05/14/2014
状态 Archive
Type 综合文章