本文使用PCF8563 芯片為嵌入式系統提供一個獨立的實時時鐘，它獨立自主地運行，CPU 從它那里獲得時間信息。文中簡介了嵌入式ARM 處理器和I2C 總線的通訊協議；通過uclinux 的交叉編譯、移植和燒寫uclinux 內核，在UP-NETARM3000 上成功的運行uclinux 系統；在移植的uclinux 系統上掛載NFS 文件系統，運行其中的應用程序；并通過C 程序在uclinux 下實現了對PCF8563 的讀寫功能，成功地添加了實時時鐘。
【關鍵詞】實時時鐘； ARM 處理器； uclinux 移植； PCF8563；I2C 總線
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