设计一个数字钟，具有以下功能：
（1）计时功能：6个数码管显示时、分、秒。
（2）校时功能：在电子钟停止运行状态下，能够修改时、分、秒的值。
（3）能使电子钟复位（清零），能启动和停止电子钟的运行。
Design a digital clock with the following functions:
(1) Timing function: 6 digital tube display hour, minute, second.
(2) Time calibration function: when the electronic clock stops running, the value of hour, minute and second can be modified.
(3) It can reset the electronic clock (reset), start and stop the operation of the electronic clock. (2020-07-03, Multisim, 323KB, 下载2次)