说明：  自动售饮料机，只可投入5毛和1块钱，每瓶饮料为2.5元，要求应用状态机设计该系统，并编写Testbench。 输入信号定义： clk：时钟输入 ngreset：复位信号 half_yuan：五毛钱 one_yuan：一元钱 输出信号定义： dispense：表示机器售出一瓶饮料 collect：用于提示投币者取走饮料 half_out：表示找回五毛钱
(Drinks vending machine can only be put into hair and a dollar per bottle of $ 2.5 requires the application of state machine design of the system, and to prepare Testbench. Input signal definition: clk: clock input ngreset: the the reset signal half_yuan: five cents one_yuan: a dollar of output signal definition: dispense: indicates that the machine sold a bottle of beverage collect: for prompt the coin by take drinks half_out away: Retrieve Fifty Cent money)