They keyboard is just another input device and has a standard protocol to go along with it. There really isn't anything too special about a keyboard. One pin on the PS/2 connector is used for data, one for a clock. The data is clocked out as you tell it to be. Making this in VHDL is far easier than it sounds.
Purpose & Overview of this project
For this project/tutorial we want to now get input from a standard PS/2 keyboard. The UP1/UP2 board has a port for a PS/2 keyboard to connect to and all the pins are hardwired to the UP1/UP2 board which makes it even easier for us. The keyboard input we receive will be able to control the bouncing ball from the previous tutorial.