a)目的：基础PWM输入也叫捕获，以及中断配合应用。使用前一章的输出管脚PB1（19脚），直接使用跳线连接输入的PA3（13脚），配置为TIM2_CH4，进行实验。



b)对于简单的PWM输入应用，暂时无需考虑TIM1的高级功能之区别，按照目前我的应用目标其实只需要采集高电平宽度，而不必知道周期，所以并不采用PWM输入模式，而是普通脉宽捕获模式。

-A) purpose: basic PWM input also called capture, and interrupt cooperate to apply. Before using a chapter of the output tube feet PB1 (19 feet), direct use of jump line join input PA3 (13 feet), configuration for the TIM2_CH4, the experiment.





B) for simple PWM input application, temporarily without thinking about the difference between the TIM1 advanced features, according to current my application target in fact only need to collect high level width, which do not need to know the cycle, so not using PWM input mode, but ordinary pulse width capture mode.