Hamster has written VHDL code for interpreting data from a PS2 keyboard. It’s currently a work in progress and is designed to work with his Papilio S6 (the Spartan 6-based Papilio board paired with the Megawing board, both available from Seeedstudio.)
The code receives the scancode from a PS2 keyboard attached to Port A of the Megawing and the four LEDs on the board indicate the low bits of the scancode of the last key pressed or released. (The high four bits are displayed when you press the Megawing’s ‘up’ button.) You can check out hamster’s code and project details at the Hamsterwork’s Wiki page.