stm32TIM4ETR配置代码

以下是 STM32 TIM4 ETR 配置代码示例：

#include "stm32f4xx.h"

void TIM4_ETR_Config(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;
  TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
  TIM_ICInitTypeDef TIM_ICInitStructure;
  NVIC_InitTypeDef NVIC_InitStructure;

  /* Enable GPIO clock */
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOE, ENABLE);

  /* Enable TIM4 clock */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);

  /* Configure TIM4 ETR pin */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
  GPIO_Init(GPIOE, &GPIO_InitStructure);

  /* Connect TIM4 ETR pin to AF2 */
  GPIO_PinAFConfig(GPIOE, GPIO_PinSource, GPIO_AF_TIM4);

  /* Configure TIM4 time base */
  TIM_TimeBaseStructure.TIM_Period = 65535;
  TIM_TimeBaseStructure.TIM_Prescaler = ;
  TIM_TimeBaseStructure.TIM_ClockDivision = ;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
  TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);

  /* Configure TIM4 input capture */
  TIM_ICInitStructure.TIM_Channel = TIM_Channel_1;
  TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;
  TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_TRC;
  TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
  TIM_ICInitStructure.TIM_ICFilter = ;
  TIM_ICInit(TIM4, &TIM_ICInitStructure);

  /* Enable TIM4 interrupt */
  NVIC_InitStructure.NVIC_IRQChannel = TIM4_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = ;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = ;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);

  /* Enable TIM4 ETR */
  TIM_SelectInputTrigger(TIM4, TIM_TS_ETRF);
  TIM_ETRClockMode1Config(TIM4, TIM_ExtTRGPSC_OFF, TIM_ExtTRGPolarity_NonInverted, );

  /* Enable TIM4 counter */
  TIM_Cmd(TIM4, ENABLE);
}