# In a constraints.ucf, how do I tell it to that an unconnected pin is ok?

I'm new FPGAs, and working through the "IntroToSpartanFPGABook" PDF.

I'm looking at the "constraints.ucf" file, and (because I'm lazy), it occurred to me that I could create one "constraints.ucf" file for my (Papilio) Megawin, which I can then use for all projects, without modification. Switch 1 will always be on the same wire.

This works ok, except that everything that I DON'T use generates a warning:

WARNING:PhysDesignRules:367 - The signal <switch_1_IBUF> is incomplete. The signal does not drive any load pins in the design.


I understand that it is 100% correct, I am not using that switch (or LED), but if I remove the declaration, I need to have a different constraint file for each project (commenting and uncommenting as I go).

Is there a way of saying the following:

NET led_0 LOC = "P3" | IOSTANDARD=LVTTL DontGenerateWarningsIfNotConnected;