When I synthesize a design instantiating GTP_DUAL in Synplify, the following error occurs:
"Illegal defparam. parameter PCS_COM_CFG cannot be found in module GTP_DUAL"
PCS_COM_CFG is an attribute for GTP_DUAL that was added in ISE 9.2i SP2.
Please download Synplify unisim library posted below (replace the one in Synplify8.9)
It should support all config in GTP_DUAL matching 9.2.02i.
For more information on issues related to using GTP_DUAL and Synplify, please see (Xilinx Answer 25475).