General Description:
When I run timing analysis on my design with a differential clock, the "P" side and the "N" side timing values do not match. Why?
This problem has been fixed in the latest 6.2i Service Pack available at:
http://support.xilinx.com/xlnx/xil_sw_updates_home.jsp
The first service pack containing the fix is 6.2i Service Pack 3.