基于单片机at89s52的简易电子时钟程序，其中是通过外部中断来实现电子时钟的计时与设置时间，实现环境为keil-Uv2。-Based on the simple electronic clock at89s52 SCM, which is through external program to realize electronic clock interrupt the timing and set a time and realize environmental Uv2 keil- for