定时器TIM2输出pwm波
#define TIM2_CLK_ENABLE() ( RCC->APB1ENR |= RCC_APB1ENR_TIM2EN )#define TIM3_CLK_ENABLE() ( RCC->APB1ENR |= RCC_APB1ENR_TIM3EN )#define TIMx_CHANNEL_GPIOA_PORT() ( RCC->IOPENR |= (RCC_IOPENR_GPI
