说明：  本文详细地介绍了在Win32环境下通过调用通信API 函数以异步方式来实现PC机和MCS 51 单片机之间的通信过程给出了软硬件设计机理以及详细的通信协议说明
(This article described in detail in the Win32 environment by calling the communication API function in order to realize asynchronous approach to PC and MCS 51 Singlechip give the communication process between the design of the mechanism of the hardware and software as well as detailed description of the communication protocol)