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