aditya417-- the answers to your questions are easily found by just reading the spartan user's guide, which should be available on Xilinx's website. The I/O pins are configurable, so all you have to do is configure them for the levels you want to connect. However, some FPGA's are not 5V tolerant ( BUT, I believe Spartan FPGA's are ) So look at the users guide and see if you can connect 5V. If so then great! If not, then you'll need to use a resistor divider to get the VOH into spec. Also, the pins have configurable pullups, pulldowns, etc, so you can talor the I/O's to your particular needs. Good luck.