Unformatted text preview: • The controller does not give any change. For example, if the coins inserted are N, D, N, D, totaling 30¢, the controller does not return the extra 5¢. • The controller does apply the extra amount deposited (5¢ in the example) as a credit to the next user. Only 20¢ needs to be inserted to obtain the next package of goodies. • The input Coin_return is active for one clock period. This activates the Return_coins output. The Return_coins output is asserted only when there is less than 25¢ credit in the machine. (The Coin Dispener device returns any coins that have been deposited since the last time Dispense_goodies was asserted.) Q D N Coin_return Clock VENDING MACHINE CONTROLLER Dispense_goodies Return_coins COIN SENSOR Single Coin Slot Q D N COIN DISPENSER Dispense_goodies Return_coins All Deposited Coins Returned Coin Box...
View Full Document
- Spring '08
- Vending machine, coin slot, single coin slot