时钟芯片ds1302的具体使用方法及其内外部结构，芯片引脚，附加简单教学程序-Clock chip ds1302 specific use and its internal and external structure, the chip pins, add a simple teaching procedures, etc.

ds1302实时时钟芯片的运用，含源代码-ds1302 real time clock chip used, with source code ...