单片机(AT89S52)实现多功能数字钟 该数字钟实现时钟运行，调整，倒计时，秒表功能，且精确度经调试一天的误差在2S内。 -SCM (AT89S52) to achieve multi-functional digital clock digital clock to achieve the clock is running, adjustment, countdown, stopwatch function, and the precision error by debugging