I am currently using ISE 8.1 and am receiving this message after entering a clock period constraint:
WARNING:XdmHelpers:662 - Period specification "TS_U1_gen_clk1" references the TNM group "U1/gen_clk1", which contains both pads and synchronous elements. The timing analyzer will ignore the pads for this specification. You might want to use a qualifier (e.g. "FFS") on the TNM property to remove the pads from this group.
This clock (2 Khz) is generated using a counter and is internal to the device. What is the correct way to specify the qualifier so this warning goes away?