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AR# 32809

Virtex-5 GTP/GTX RocketIO - ERROR:LIT:448 - CLKIN of GTP_DUAL symbol "rocketio_wrapper_i/tile0_rocketio_wrapper_i/gtp_dual_i" is not driven by an IBUFDS, IBUFGDS or GT


Keywords: GREFCLK, fabric, GTP, GTX, bufg, bufr

In ISE 11.1, it is possible to see the following error during MAP when a fabric clock is used as a reference clock:

"ERROR:LIT:448 - CLKIN of GTP_DUAL symbol "rocketio_wrapper_i/tile0_rocketio_wrapper_i/gtp_dual_i" is not driven by an IBUFDS, IBUFGDS or GT"

This Answer Record discusses how to work around this error.


When using fabric clocking resources to drive the CLKIN port of either a GTP or GTX, either a BUFG or BUFR can be used for lower line rate applications. If these primitives are being used and the above error is seen while running MAP, please set the following environment variable:


This will disable the DRC which causes the error. Be aware that this also disables a number of other DRCs related to the GTP/GTX. This will be corrected in future versions of the design tools.
AR# 32809
Date Created 06/02/2009
Last Updated 06/02/2009
Status Active
Type General Article