Looks to me that P207 on the Spartan-3 parts is the dedicated PROGRAM
> pin for the FPGA and thus a user signal can not be assigned to that pin.
> It is and always will be the pin to reset configuration and thus the
> software can not do anything to change that pin and does not even really
> know of its existance because of this. That pin should be properly
> connected to the board as said in the documentation for Spartan-3 but
> nothing should be done with that pin from within the software.
>
>
> -- Brian
Thanks,Brian. Meantime I have looked at the pin description of S3 board and P207 belongs to the CONFIG pin type which is not available for user I/O. Thanks anyway for your explanation.
Chao.