要求设计一个带闹钟功能的24小时计时器

它包括以下几个组成部分：

① 显示屏：4个七段数码管显示当前时间(时：分)或设置的闹钟时间；一个发光二极管以1HZ的频率跳动，用于显示秒；

② 按键key1，用于设置调时还是调分；

③ 按键key2，用于输入新的时间或新的闹钟时间，每按下一次，时或分加1；

④ TIME(时间)键，用于确定新的时间设置；

⑤ ALARM(闹钟)键，用于确定新的闹钟时间设置，或显示已设置的闹钟时间；

⑥ 扬声器，在当前时钟时间与闹钟时间相同时，发出蜂鸣声。

-To design a 24-hour alarm clock with a timer which includes the following components: ① Display: 4 segment digital tube displays the current time (hours: minutes) or set the alarm time　a light-emitting diode to the frequency of 1HZ beating, is used to display seconds　② keys key1, when used to set the tone or the tone pm　③ key key2, used to enter the new time or a new alarm time, every time you press, or points plus 1　④ TIME ( time) key, used to determine the new time settings　⑤ ALARM (alarm) button, used to determine a new set alarm time, or set the alarm time is displayed　⑥ Speaker, in the current time and alarm clock the same time, issue beep.