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# 13119

8.1i Virtex-II MAP - Why are my OBUFDS components not using the DIFFO signals for LVPECL?


When I design with an OBUFDS and use LVPECL, the tools do not utilize the DIFFO_OUT in the DIFFM and the DIFFO_IN in the DIFFS. Why?


The DIFFO_IN connection, which is used for LVDS outputs, is not supported in the hardware for LVPECL_33 outputs. For LVPECL_33 outputs, normal output paths are used to drive both DIFFM and DIFFS paths. A MAXSKEW constraint should be used to minimize skew between the DIFFM and DIFFS paths.

AR# 13119
Date Created 08/29/2007
Last Updated 12/15/2012
Status Active
Type General Article