本题目的主要要求是要实现闹钟的功能内容：设计一个能够显示时分秒的数字时钟，时间显示为12小时制，除了显示分时秒外，并能实现上，下午。可以进行手动校时，定时（完成此题目时要有适当的设置，确定灯按钮，单，双灯作为报警显示），同时还应该能够清零。-the subject of the main demands is to achieve the alarm clock function : to design a display of accurate digital clock, the time displayed by the system for 12 hours, showing the time of seconds, and can achieve the afternoon. Can manually school, regular (completion of this topic have appropriate settings, to determine button lights alone, as the police showed two-lamp), but also should be able to reset.