在以单片机为核心的多级分布式系统中,常常需要扩展单片机的串行通信口,本文分别介绍了基于SP2538 专用串行口扩展芯片及Intel8251 的两种串行口扩展方法,并给出了实际的硬件电路原理及相应的通信程序段。 关键词:串口扩展;单片机;SP2538;Intel8251 Abstract: The serial interface of microcontroller is often to be expanded in multi-step distributed system based on single-chip microcomputer. In this paper, two solutions of serial expanding based on expert serial interface expanding chip sp2538 and Intel8251 are introduced, and the multi-serial interface hardware circuit and the corresponding communication programs based on microcontrollers are listed. Keywords: Serial-expanding; Single-chip Microcomputer; SP2538; Intel8251