60s

代码说明：

  该程序为初学者学习单片机时使用的60S倒计时程序，可将开程序用在proteus软件上进行仿真，我试过可行的~(The program for beginners to learn the use of single-chip microcomputer of the 60S countdown procedures, can be used in open procedures proteus simulation software, I tried to possible ~)