用VERILOG实现秒表的开发设计，(1)熟悉按键扫描、按键防抖和数码管驱动接口电路原理；(2)掌握按键扫描、按键防抖和数码管驱动接口电路设计开发；(3)掌握状态机实际应用设计。-To achieve the development of a stopwatch with VERILOG Design, (1) be familiar with key scanning, image stabilization and digital control key driver interface c