说明：  定时器：作用一:计数概念的引入 作用二:定时 作用三:溢出 单片机提供内部定时和外部计数的功能,功能差不多都是定时和计数达到终点时,产生中断,而CPU则暂时放下目前所执行的程序区处理中断。 定时器:主要用于产生固定时间(比较精确),也可以作为UART等外设的频率发生器。
(Timer: function one: the introduction of the concept of counting function two: timing function three: overflow MCU provides the function of internal timing and external counting. The function is almost all when the timing and counting reach the end point, it will produce interruption, while CPU temporarily puts down the program area currently executed to handle the interruption. Timer: it is mainly used to generate fixed time (relatively accurate), and can also be used as a frequency generator of UART and other peripheral devices.)