在实验箱上设计并实现一个带闹钟的日历钟，要求至少用到端口功能、按键中断功能、外部中断功能、LCD功能、8位定时器/事件计数器5的定时功能、实时计数器的日历和时钟功能。-Experimental tank design and a calendar with alarm clock, requires at least use the port function key interrupt function, the external interrupt function, LCD function, the timing of the 8-bit timer/event counter, real-time counter calendar and clock functions.