利用单片机的内部定时器和实验仪上提供的数码管显示电路，设计一个电子时钟，显示格式如下：XX XX XX有左向右分别表示为：时 分 秒。

-Available on the use of MCU internal timer and experimental instrument digital display circuit design of an electronic clock display format is as follows: XX XX XX with left to right are represented by: points seconds.