说明：  状态机是逻辑设计的重要内容，状态机的设计水平直接反应工程师的逻辑功底，所以许 多公司的硬件和逻辑工程师面试中，状态机设计几乎是必选题目。本章在引入状态机设计思想的基础上，重点讨论如何写好状态机。
(State machine is an important part of logic design, state machine design engineers a direct response to the logic level of skills, so the company s hardware and logic more than engineers interview, state machine design is almost must-topic. The introduction of this chapter, the state machine design thinking Like basis, focused on how to write a state machine.)