UPGRADE YOUR BROWSER

We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

AR# 15063

Virtex-II Pro RocketIO - If I am using a 2-byte data path, can I forego a DCM and drive the USRCLK and USRCLK2 inputs with a REFCLK input?

描述

If I am using a 2-byte data path, can I forego a DCM and drive the USRCLK and USRCLK2 inputs with a REFCLK input?

解决方案

A DCM is used to provide clock skew compensation between TXUSRCLK2 at flip-flops within the FPGA fabric and the REFCLK input at the external pad. This will be an issue if the REFCLK input is being used to clock data into or out of the chip. 

 

If the REFCLK input is not being used for this purpose (i.e., if it is being used only inside the chip), it is possible to not use the DCM. However, we recommend that you use a BUFG if possible to minimize clock skew within the chip.

AR# 15063
日期 05/14/2014
状态 Archive
Type 综合文章
的页面