STM32L0系列之【LPTIM定时器】

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1.LPTIM介绍

STM32L0系列有个LPTIM定时器，即lowpowertimer,低功耗定时器

可以看到可供LPTIM使用时钟源分为如下：
内部时钟源：LSE，LSI，HSI或APB时钟
外部时钟源：LPTIM输入的外部时钟源
ps：如果以LSE，LSI或外部时钟为时钟源时，能够从停止模式唤醒设备。

本文记录使用LSI为时钟源使用LPTIM

2.配置时钟源并且启动

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
  RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};

  /** Configure the main internal regulator output voltage 
  */
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
  /** Initializes the CPU, AHB and APB busses clocks 
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI|RCC_OSCILLATORTYPE_MSI;
  RCC_OscInitStruct.LSIState = RCC_LSI_ON;
  RCC_OscInitStruct.MSIState = RCC_MSI_ON;
  RCC_OscInitStruct.MSICalibrationValue = 0;
  RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_6;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }
  /** Initializes the CPU, AHB and APB busses clocks 
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_MSI;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
  {
    Error_Handler();
  }

    PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_RTC|RCC_PERIPHCLK_LPTIM1;
    PeriphClkInit.RTCClockSelection = RCC_RTCCLKSOURCE_LSI;
    PeriphClkInit.LptimClockSelection = RCC_LPTIM1CLKSOURCE_LSI;

    if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
    {
    Error_Handler();
    }
}

以上是完整的时钟配置函数，使用LPTIM最主要的配置由如下构成：

RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI;
RCC_OscInitStruct.LSIState = RCC_LSI_ON;
HAL_RCC_OscConfig(&RCC_OscInitStruct);

PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_LPTIM1;
PeriphClkInit.LptimClockSelection = RCC_LPTIM1CLKSOURCE_LSI;
HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit);

3.初始化配置LPTIM

/**
  * @brief LPTIM1 Initialization Function
  * @param None
  * @retval None
  */
void MX_LPTIM1_Init(void)  //0.037Mhz  (1+period / 0.037(37000)) = 1s period=36999
{
  hlptim1.Instance = LPTIM1;
  hlptim1.Init.Clock.Source = LPTIM_CLOCKSOURCE_APBCLOCK_LPOSC;
  hlptim1.Init.Clock.Prescaler = LPTIM_PRESCALER_DIV1;
  hlptim1.Init.Trigger.Source = LPTIM_TRIGSOURCE_SOFTWARE;
  hlptim1.Init.OutputPolarity = LPTIM_OUTPUTPOLARITY_HIGH;
  hlptim1.Init.UpdateMode = LPTIM_UPDATE_IMMEDIATE;
  hlptim1.Init.CounterSource = LPTIM_COUNTERSOURCE_INTERNAL;
  if (HAL_LPTIM_Init(&hlptim1) != HAL_OK)
  {
    Error_Handler();
  }
}

4.LPTIM中断处理函数

void LPTIM1_IRQHandler(void)
{
  HAL_LPTIM_IRQHandler(&hlptim1);
}

5.启用LPTIM，中断触发回调函数

启用LPTIM分为多种方式：如脉冲，PWM，计数等。
具体可参考HAL_LPTIM_IRQHandler函数的实现。

/**
  * @brief  Handle LPTIM interrupt request.
  * @param  hlptim LPTIM handle
  * @retval None
  */
void HAL_LPTIM_IRQHandler(LPTIM_HandleTypeDef *hlptim)
{
  /* Compare match interrupt */
  if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_CMPM) != RESET)
  {
    if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_CMPM) != RESET)
    {
      /* Clear Compare match flag */
      __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_CMPM);

      /* Compare match Callback */
#if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
      hlptim->CompareMatchCallback(hlptim);
#else
      HAL_LPTIM_CompareMatchCallback(hlptim);
#endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
    }
  }

  /* Autoreload match interrupt */
  if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_ARRM) != RESET)
  {
    if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_ARRM) != RESET)
    {
      /* Clear Autoreload match flag */
      __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_ARRM);

      /* Autoreload match Callback */
#if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
      hlptim->AutoReloadMatchCallback(hlptim);
#else
      HAL_LPTIM_AutoReloadMatchCallback(hlptim);
#endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
    }
  }

  /* Trigger detected interrupt */
  if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_EXTTRIG) != RESET)
  {
    if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_EXTTRIG) != RESET)
    {
      /* Clear Trigger detected flag */
      __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_EXTTRIG);

      /* Trigger detected callback */
#if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
      hlptim->TriggerCallback(hlptim);
#else
      HAL_LPTIM_TriggerCallback(hlptim);
#endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
    }
  }

  /* Compare write interrupt */
  if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_CMPOK) != RESET)
  {
    if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_CMPOK) != RESET)
    {
      /* Clear Compare write flag */
      __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_CMPOK);

      /* Compare write Callback */
#if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
      hlptim->CompareWriteCallback(hlptim);
#else
      HAL_LPTIM_CompareWriteCallback(hlptim);
#endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
    }
  }

  /* Autoreload write interrupt */
  if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_ARROK) != RESET)
  {
    if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_ARROK) != RESET)
    {
      /* Clear Autoreload write flag */
      __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_ARROK);

      /* Autoreload write Callback */
#if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
      hlptim->AutoReloadWriteCallback(hlptim);
#else
      HAL_LPTIM_AutoReloadWriteCallback(hlptim);
#endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
    }
  }

  /* Direction counter changed from Down to Up interrupt */
  if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_UP) != RESET)
  {
    if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_UP) != RESET)
    {
      /* Clear Direction counter changed from Down to Up flag */
      __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_UP);

      /* Direction counter changed from Down to Up Callback */
#if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
      hlptim->DirectionUpCallback(hlptim);
#else
      HAL_LPTIM_DirectionUpCallback(hlptim);
#endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
    }
  }

  /* Direction counter changed from Up to Down interrupt */
  if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_DOWN) != RESET)
  {
    if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_DOWN) != RESET)
    {
      /* Clear Direction counter changed from Up to Down flag */
      __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_DOWN);

      /* Direction counter changed from Up to Down Callback */
#if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
      hlptim->DirectionDownCallback(hlptim);
#else
      HAL_LPTIM_DirectionDownCallback(hlptim);
#endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
    }
  }
}

这里示例TimeOut的方式回调。
开启LPTIM定时器需要调用 HAL_LPTIM_TimeOut_Start_IT

//HAL_LPTIM_TimeOut_Start_IT  <=> HAL_LPTIM_CompareMatchCallback
void HAL_LPTIM_CompareMatchCallback(LPTIM_HandleTypeDef *hlptim)
{
    HAL_GPIO_TogglePin(GPIOB,GPIO_PIN_8);
}

6.main.c 主函数

int main(void) 
{
    HAL_Init();
    /* Configure the system clock */
    SystemClock_Config();
    
    MX_LPTIM1_Init();
    //(1+period / 0.037(37000)) = 1s period=36999  1s触发一次
    HAL_LPTIM_TimeOut_Start_IT(&hlptim1,36999,1000);
    while(1){
        HAL_Delay(1000);
    }

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