DE2 Quartus debounced circuit

Actually, I believe DE2 switches are debounced with a 74HC245. You should not see multiple inputs for a single button depression. Remember that the switches (or 'key's) are active high. When you push the button it will be low for the period of time that you have it depressed (which even if you push it very quickly will be many thousands of clock cycles). But you will not see it oscillate between a one and a zero after it is depressed (you can prove this to yourself by building a simple SignalTap file and analyzing the operation in hardware). In order to ensure your circuit operates appropriately I would suggest that you watch for the switch (or key) to go from a low to a high (the switches are a logic 1 when not depressed). This will ensure that a single button press results in your code executing only once. If you post your code snippet, then I will have a look...