数字跑表，具有复位，暂停，秒表计时等功能。分为时钟输入，复位和启动，暂停。。。 复位信号高电平有效，可对跑表异步清零。-Digital stopwatch with reset, suspend, stopwatch and other functions. Divided clock input, reset, and start, pause. . . Active high reset signal, can stopwa