设计一个出租车计费器，能按路程计费，具体要求如下：

（１）实现计费功能，计费标准为：按行驶里程计费，起步价为6.00元，并在汽车行驶2km后按1.2元／km计费，当里程数达到15km后，没千米加收50 的空驶费，车辆停止和暂停时不计费。

（２）现场模拟汽车的启动、停止、暂停和换挡等状态。

（３）设计数码管显示电路，将车费和路程显示出来，各有１位小数。

-Design of a taxi meter, to the journey billing, specific requirements are as follows: (1) implement accounting functions, billing criteria: billing by mileage, starting at 6.00 yuan, and in the car driving 2km press 1.2 yuan/km charge, when the mileage to 15km later, not one thousand meters subject to 50　of the Kongshi fees, vehicle stop and pause without charge. (2) on-site simulation of the car to start, stop, pause, and shift other state. (3) design digital display circuit, the fare and distance are displayed, each with a decimal.