STM32F4外部时钟ETR无法计数

lowell · 发表于 2019-1-17 17:39:20

本帖最后由 lowell 于 2019-1-19 15:12 编辑

使用TIM14通道一PF9发出PWM波来模拟外部信号，TIM3的ETR引脚PD2输入外部时钟信号，TIM3计数产生中断，中断函数内翻转电平。
但是查看TIM3的计数寄存器发现计数值始终不变，不知道哪里配置错了，各位不吝赐教。
PWM代码：
void TIM14_PWM_Init(u32 arr,u32 psc)
{
      RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM14 ,ENABLE);
      RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOF ,ENABLE);

      GPIO_InitTypeDef GPIO_InitStruct;

      GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
      GPIO_InitStruct.GPIO_Pin = GPIO_Pin_9;
      GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
      GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL ;
      GPIO_InitStruct.GPIO_Speed = GPIO_Speed_100MHz;
      GPIO_Init(GPIOF,&GPIO_InitStruct);

      //引脚复用功能选择
      GPIO_PinAFConfig(GPIOF,GPIO_PinSource9,GPIO_AF_TIM14);

      //时基模块初始化
      TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;

      TIM_TimeBaseInitStructure.TIM_Period = arr;
      TIM_TimeBaseInitStructure.TIM_Prescaler = psc;
      TIM_TimeBaseInitStructure.TIM_ClockDivision  = 0 ;
      TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;
      TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up ;

      TIM_TimeBaseInit(TIM14,&TIM_TimeBaseInitStructure);

      //输出比较模块初始化
      TIM_OCInitTypeDef TIM_OCInitStruct;

      TIM_OCInitStruct.TIM_OCMode = TIM_OCMode_PWM1;
      TIM_OCInitStruct.TIM_OCPolarity = TIM_OCPolarity_High ;
      TIM_OCInitStruct.TIM_OutputState = TIM_OutputState_Enable;

      TIM_OC1Init(TIM14,&TIM_OCInitStruct);

      TIM_OC1PreloadConfig(TIM14, TIM_OCPreload_Enable ); //使能TIM14在CCR1上的预加载寄存器
      TIM_ARRPreloadConfig(TIM14, ENABLE);                //ARPE使能

      TIM_Cmd(TIM14,ENABLE);

}
TIM3外部时钟：
//通用定时器3中断初始化
//arr：自动重装值。
//psc：时钟预分频数
//定时器溢出时间计算方法:Tout=((arr+1)*(psc+1))/Ft us.
//Ft=定时器工作频率,单位:Mhz
//这里使用的是定时器3!
void TIM3_Int_Init(u32 arr,u32 psc)
{
      /************时基单元配置******************************/
      RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3,ENABLE);  ///使能TIM3时钟

      TIM_DeInit(TIM3);

      TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
  TIM_TimeBaseInitStructure.TIM_Period = arr;       //自动重装载值
      TIM_TimeBaseInitStructure.TIM_Prescaler=psc;  //定时器分频
      TIM_TimeBaseInitStructure.TIM_CounterMode=TIM_CounterMode_Up ; //向上计数模式
      TIM_TimeBaseInitStructure.TIM_ClockDivision=TIM_CKD_DIV1;
      TIM_TimeBaseInit(TIM3,&TIM_TimeBaseInitStructure);//初始化TIM3

      /************NVIC配置******************************/
      NVIC_InitTypeDef NVIC_InitStructure;

      NVIC_InitStructure.NVIC_IRQChannel=TIM3_IRQn; //定时器3中断
      NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0x01; //抢占优先级1
      NVIC_InitStructure.NVIC_IRQChannelSubPriority=0x03; //子优先级3
      NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
      NVIC_Init(&NVIC_InitStructure);

      /************所用到的ETR外部输入引脚配置******************************/

         GPIO_InitTypeDef GPIO_InitStructure;
               RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);

         GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_2;
         GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
         GPIO_InitStructure.GPIO_OType  =GPIO_OType_PP  ;
         GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
         GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
         GPIO_Init(GPIOD, &GPIO_InitStructure);
               GPIO_PinAFConfig(GPIOD,GPIO_PinSource2,GPIO_AF_TIM3);

            TIM_ETRClockMode2Config(TIM3,TIM_ExtTRGPSC_OFF  ,TIM_ExtTRGPolarity_Inverted,  0x00);

            TIM_ClearFlag (TIM3,TIM_IT_Update);
            TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE); //允许定时器3更新中断
            TIM_SetCounter( TIM3, 0);
            TIM_Cmd(TIM3,ENABLE); //使能定时器3
}

//定时器3中断服务函数
void TIM3_IRQHandler(void)
{
      if(TIM_GetITStatus(TIM3,TIM_IT_Update|TIM_IT_Trigger)==SET) //溢出中断
      {
            LED1=!LED1;//DS1翻转
      }
      TIM_ClearITPendingBit(TIM3,TIM_IT_Update);  //清除中断标志位
}

主函数：
#include "sys.h"
#include "delay.h"
#include "usart.h"
#include "led.h"
#include "timer.h"
#include "pwm.h"

int main(void)
{
      NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);//设置系统中断优先级分组2
      delay_init(168);  //初始化延时函数
      uart_init(115200);
      LED_Init();                               //初始化LED端口
  TIM14_PWM_Init(500-1,8400-1);//定时器时钟84M，分频系数8400，84M/8400=10Khz的计数频率
      TIM_SetCompare1(TIM14,250);

      TIM3_Int_Init(5-1,840-1);

      while(1)
      {
               delay_ms(300);
               printf("Counter:%d  \r\n",TIM_GetCounter (TIM2));
      }
}
这是TIM3初始化之后寄存器的值：

lowell · 发表于 2019-1-17 17:39:21

problem solved!
两处问题，
一是GPIO要配置成AF,并复用到TIM3,
二是配置完外部时钟函数，得到的是CK_PSC,还会经过定时器自身的分频，再得到时钟CK_CNT计数，之前TIM3的分频系数太大了
附能用的程序：
void TIM3_Int_Init(u32 arr,u32 psc)
{
      /************时基单元配置******************************/
      RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3,ENABLE);  ///使能TIM3时钟

      TIM_DeInit(TIM3);

      TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
      TIM_TimeBaseInitStructure.TIM_Period = arr;       //自动重装载值
      TIM_TimeBaseInitStructure.TIM_Prescaler=psc;  //定时器分频
      TIM_TimeBaseInitStructure.TIM_CounterMode=TIM_CounterMode_Up ; //向上计数模式
      TIM_TimeBaseInitStructure.TIM_ClockDivision=TIM_CKD_DIV1;
      TIM_TimeBaseInit(TIM3,&TIM_TimeBaseInitStructure);//初始化TIM3

      /************NVIC配置******************************/
      NVIC_InitTypeDef NVIC_InitStructure;

      NVIC_InitStructure.NVIC_IRQChannel=TIM3_IRQn; //定时器3中断
      NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0x01; //抢占优先级1
      NVIC_InitStructure.NVIC_IRQChannelSubPriority=0x03; //子优先级3
      NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
      NVIC_Init(&NVIC_InitStructure);

      /************所用到的ETR外部输入引脚配置******************************/

         GPIO_InitTypeDef GPIO_InitStructure;
               RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);

         GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_2;
         GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
         GPIO_InitStructure.GPIO_OType  =GPIO_OType_PP  ;
         GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
         GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
         GPIO_Init(GPIOD, &GPIO_InitStructure);
         GPIO_PinAFConfig(GPIOD,GPIO_PinSource2,GPIO_AF_TIM3);

            TIM_ETRClockMode2Config(TIM3,TIM_ExtTRGPSC_OFF  ,TIM_ExtTRGPolarity_Inverted,  0x00);

            TIM_ClearFlag (TIM3,TIM_IT_Update);
            TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE); //允许定时器3更新中断
            TIM_SetCounter( TIM3, 0);
            TIM_Cmd(TIM3,ENABLE); //使能定时器3
}

//定时器3中断服务函数
void TIM3_IRQHandler(void)
{
      if(TIM_GetITStatus(TIM3,TIM_IT_Update|TIM_IT_Trigger)==SET) //溢出中断
      {
            LED1=!LED1;//DS1翻转
      }
      TIM_ClearITPendingBit(TIM3,TIM_IT_Update);  //清除中断标志位
}
#include "sys.h"
#include "delay.h"
#include "usart.h"
#include "led.h"
#include "timer.h"
#include "pwm.h"

#define TIM14_PWM_ARR 600
#define TIM14_PWM_DUTY TIM14_PWM_ARR/2  //50%
int main(void)
{
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);//设置系统中断优先级分组2

LED_Init(); //初始化LED端口
//  TIM14_PWM_Init(TIM14_PWM_ARR-1,8400-1);//定时器时钟84M，分频系数8400，84M/8400=10Khz的计数频率
// TIM_SetCompare1(TIM14,TIM14_PWM_DUTY);
//
// TIM2_Int_Init(50-1,1-1);
   TIM14_PWM_Init(500-1,8400-1);//定时器时钟84M，分频系数8400，84M/8400=10Khz的计数频率
      TIM_SetCompare1(TIM14,250);

      TIM2_Int_Init(50-1,1-1);
TIM3_Int_Init(50-1,1-1);
delay_init(168);  //初始化延时函数
uart_init(115200);
while(1)
{
   delay_ms(500);
   //printf("Counter2:%d  \r\n",TIM_GetCounter (TIM2));
   printf("Counter3:%d  \r\n",TIM_GetCounter (TIM3));
}
}