本文使用PCF8563 芯片为嵌入式系统提供一个独立的实时时钟,它独立自主地运行,CPU 从它那里获得时间信息。文中简介了嵌入式ARM 处理器和I2C 总线的通讯协议;通过uclinux 的交叉编译、移植和烧写uclinux 内核,在UP-NETARM3000 上成功的运行uclinux 系统;在移植的uclinux 系统上挂载NFS 文件系统,运行其中的应用程序;并通过C 程序在uclinux 下实现了对PCF8563 的读写功能,成功地添加了实时时钟。 【关键词】实时时钟; ARM 处理器; uclinux 移植; PCF8563;I2C 总线 Abstract:This paper uses one real-time clock chip PCF8563 to give embedded systems an independent real-time clock,it runs independently, CPU receives time information from it.The paper introduced embedded ARM processor of the mainstream, explained I2C bus communication protocol。Have compiling, transplanting and burning uclinux kernel, successfully operate uclinux system on UP-NETARM3000. Mounting NFS file system in transplanted uclinux system,operate the application program among NFS file system. Using a C program to carry out the function of reading and writing PCF8563, succeed in adding the real-time clock under uclinux. Keywords:Real-time clock; ARM processor; uclinux transport; PCF8563; I2C bus