文档介绍：I 目录 1 设计方案论 功能要求····················································· 方案确定····················································· 单片机芯片的选择方案和论证........................................................... 2 显示模块选择方案和论证................................................................... 2 时钟芯片的选择方案和论证............................................................... 3 电路设计最终方案确定....................................................................... 3 2 主控制器和外围器件.............................................................................. 3 2 .1AT89S52 单片机............................................................................................... 3 2 .2DS1302 时钟芯片............................................................................................. 3 2 . 芯片介绍.................................................................................. 3 2 . 的应用..................................................................................... 6 LED ..................................................................................................... 6 74HC138 ............................................................................................. 7 74LS244 .............................................................................................. 7 3 硬件设计.................................................................................................. 8 .................................................................................................. 8 .......................................................................................................... 8 .......................................................................................................... 8 .......................................................................................... 8 .................................................................................. 8 ..