倒计时钟（分，秒，毫秒），功能如下：1）开机运行后，在LCD上实时显示倒计时起始时间（包括分、秒、毫秒），显示格式自定，并可显示其他相关信息；2）能通过KEY按键调整时间值，如分、秒、毫秒的加减等；3）能够在两位LED数码管上单独显示分或秒；4）能通过KEY按键控制倒计时的开始、中止、继续、停止、重新启动-Countdown clock (hours, seconds, milliseconds), the following functions: 1) start running in the LCD display real-time countdown to the start time (including minutes, seconds, milliseconds), display format, custom, and may display other relevant information　 2) through the KEY button to adjust the time value, such as minutes, seconds, milliseconds of addition and subtraction, etc.　3) is able to separate the two LED digital tube display minutes or seconds　4) through the KEY button controls the start of the countdown, suspend, continue, stop, restart