本设计利用STC89C51单片机的定时器/计数器定时和计数的原理，使其能精确计时。利用中断系统使其能实现开始暂停的功能。根据要求知道秒表设计主要实现的功能是计时和显示。因此设置了三个按键和LED显示时间，三个按键分别是开始、停止和复位按键。利用这三个建来实现秒表的全部功能，而LED则能显示最多59.99秒的计时。-This design uses STC89C51 microcontroller timer/counter timer counting principle and that it can accurately timed. Use interrupt system so that it can achieve the functions suspended. According to the requirements of the design know stopwatch main function is to timing and display. Therefore, a set of three buttons and LED display time, three buttons are the start, stop and reset button. Use of these three was built to achieve the full functionality of a stopwatch, while the LED is able to display up to the timing of 59.99 seconds.