General Description:
When setting up clocking wizard for a Virtex-II Pro design, clocking wizard does not allow setting the feedback
to "2X". Why?
The 2X feedback is not supported in Virtex-II Pro Devices. Please refer to (Xilinx Answer 18343) for more information.
This restriction is implemented in the latest 6.2i Service Pack available at:
http://support.xilinx.com/xlnx/xil_sw_updates_home.jsp
The first service pack containing this update is 6.2i Service Pack 2.