原创 使用TIMx_CH1作为计数器时钟

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

由于使用了TI1F_ED它的结构如下：

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。

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 = 65535;        
 TIM_TimeBaseStructure.TIM_Prescaler = 5000;     
 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,0);

 TIM_Cmd(TIM1, ENABLE);

}

int main(void)
{
 RCC_Configuration();
 GPIO_Config();
 TIM1_Init();
 /* Setup SysTick Timer for 1 msec interrupts  */
 if (SysTick_Config(SystemFrequency / 1000))
 {
 /* Capture error */
 while (1);
 }

  while (1)
  {}
}

void SysTick_Handler(void)
{
 static u32 i =0;
   
   
    if (i== 0)
    {
      i= 1;
      gusData = 0;
      TIM_SetCounter(TIM1,0);

     
    }
    else
    {
        i = 0;
        gusData = TIM_GetCounter(TIM1);

    }
   
}