The state of unused I/O can be set via the BitGen option:
bitgen -g Unusedpin:Pullup
For a list of BitGen options available for Virtex devices, type "bitgen -h virtex."
NOTES:
- Replace "virtex" with the appropriate device architecture if necessary.
- The first value listed is the default value. For example, "Pulldown" is the default value of "UnusedPin option: UnusedPin Pulldown, Pullup, Pullnone."
- 3.1i design tools do not list this option for "bitgen -h virtex" command. The option works for this device, but was missing from the command help information.
This is fixed in the 4.1i design tools release.
Unused PWRDNW or JTAG pins can be given an internal pull-up by setting the option in BitGen.