摘要
由于在MCS-51单片机开发中P0口经常作为地址/数据复用总线使用,P2口作为高8位地址线使用,P3口用作第二功能(定时计数器、中断等)使用,所以对于51单片机的4个I/O口,其可以作为基本并行输入/输出口使用的只有P1口。因此在单片机的开发中,对于并行I/O口的扩展十分重要,主要分析3种扩展并行I/O口的方法。
In the development of MCS-51 microcontroller , P0 port is often used as address/data multiplexing bus , P2 port is used as high 8 address lines , and P3 port is used as a second function ( timer , interrupt and so on ) , so only P1 port can be used as a basic parallel I/O port in microcontroller′s 4 I/O port . So extend parallel I/O port is particularly important , and the three methods of extending parallel I/O port are analyzed mainly .
出处
《微型机与应用》
2013年第24期28-30,共3页
Microcomputer & Its Applications
