目 录
1.引言.....................................................................................................................................1
2.系统方案论证及设计.........................................................................................................2
2.1 系统方案论证...........................................................................................................2
2.2 系统方案设计...........................................................................................................2
3.系统硬件电路设计.............................................................................................................4
3.1 单片机最小系统电路设计.......................................................................................4
3.2 单片机内部定时器...................................................................................................5
3.3 单片机与数码管的连接电路设计...........................................................................6
3.3.1 LED 数码显示器的结构 ...............................................................................6
3.3.2 LED 数码管显示方式 ...................................................................................8
3.4 按键调整电路设计...................................................................................................8
4.系统软件设计.....................................................................................................................9
4.1 主程序流程图...........................................................................................................9
4.2 子程序流程图.........................................................................................................12
4.2.1 键盘扫描程序设计.......................................................................................12
4.2.2 倒计时模块子程序设计..............................................................................13
5.实物调试...........................................................................................................................16
5.1 软件仿真................................................................................................................16
5.2 调试........................................................................................................................17
5.2.1 系统调试工具 Keil uVision3 .......................................................................17
5.2.2 调试的主要方法...........................................................................................18
6.总结及致谢.......................................................................................................................20
参考文献（references）： ...................................................................................................21
附录 程序............................................................................................................................21
