sTM32 使用TIMx_CH1作为 Tx1F_ED 计数器时钟

环境:iar arm 5.3

stm32f103vbt6

使用PA.8 外部输入10Mhz的方波。可从systick中断得到数据4.

4×5000（预分频值）×1000（tick中断时间）=20MHz

属于双边沿检测，一个PA.8个脉冲有2个边沿，所以时钟加倍。

由于使用了TI1F_ED它的结构如下：

void RCC_Configuration( void )
{
  /* Setup STM32 system (clock, PLL and Flash configuration) */
  SystemInit( );

  /* Enable GPIOA, GPIOC and USART1 clock  */
  RCC_APB2PeriphClockCmd(
    RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOC | RCC_APB2Periph_TIM1, ENABLE );
}

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);

void TIM1_Init( void )
{

  TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;

  TIM_TimeBaseStructure.TIM_Period = ;
  TIM_TimeBaseStructure.TIM_Prescaler = ;
  TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
  TIM_TimeBaseInit( TIM1, &TIM_TimeBaseStructure );

  TIM_TIxExternalClockConfig( TIM1, TIM_TIxExternalCLK1Source_TI1ED,
    TIM_ICPolarity_Rising,  );

  TIM_Cmd( TIM1, ENABLE );

}

int main( void )
{
  RCC_Configuration( );
  GPIO_Config( );
  TIM1_Init( );
  /* Setup SysTick Timer for 1 msec interrupts  */
  if ( SysTick_Config( SystemFrequency /  ) )
  {
    /* Capture error */
    while (  )
      ;
  }

  while (  )
  {
  }
}

void SysTick_Handler( void )
{
  static u32 i = ;

  if ( i ==  )
  {
    i = ;
    gusData = ;
    TIM_SetCounter( TIM1,  );

  }
  else
  {
    i = ;
    gusData = TIM_GetCounter( TIM1 );

  }

}