说明：  一、实现功能： 1、具有校准功能。程序开始前，可以通过校准功能，实现本地时间的设置，接着可以设置闹钟的时间。 2、具有时间显示功能。调节电平开关K1K0可改变数码管显示内容，K1K0=00时显示秒钟值，K1K0=01时显示分钟值，K1K0=10时显示小时值。 3、具有闹钟功能。当预设的闹铃时间到时，喇叭会响起音乐铃声，此时其余各部分功能与正常计时的情况相同，将电平开关K5置为低电平可停止铃声，恢复高电平可恢复铃声。若不采取任何动作，一分钟后铃声自动停止，预置的闹铃时间仍为有效。
(One to achieve functions: 1, has calibration functions. Procedures before the start of function can be calibrated to achieve local time settings, then you can set the alarm time. 2, a time display function. Adjust level switch K1K0 can change the digital tube display, K1K0 = 00 seconds, when the display value, K1K0 = 01 minutes when the display value, K1K0 = 10 is displayed when the value of hours. 3, with alarm clock function. When the preset alarm time is reached, the speaker will be sounded musical tones, this time the remaining part of the normal timing functions and the same situation as the K5-level switch is set to low to stop the tone, restore high recoverable ringtones. Failure to take any action, one minute after the tone automatically stop, preset alarm time is still valid. )