设计一个自动售货机，此机能出售1元、2元、5元、10元的四种商品。用于modelsim verilog 语言的编写-To design a vending machine, this function is the sale of 1 yuan, 2 yuan, 5 yuan, 10 yuan of the four commodities. The sale of what kind of goods to the customer pressing a button and digital display of the price of this commodity