05-31-2012 05:15 AM
haven't you searched this forum or comp.arch.fpga before?
This question has been asked often.
Logically you can see it as a ROM, the actual implemetation is more like a big MUX, in the end it's all transistors on the silicon.
See other threads for details.
Have a nice synthesis
06-20-2012 08:02 AM
Look up "look up tables"
Or, you could look up the Xilinx patent that started it all:
Xilinx San Jose