Тактовая частота.

[Nipochomus]

Не могу разобраться с тактовой частотой в проекте с использованием стандартных библиотек.
Контроллер STM32f105VC, внешний кварц с частотой 10 МГЦ. Данный контроллер относится к линейки connectivity line (CL)

Дергаем ножкой микроконтроллера с частотой 5 кГц (прерывание наступает с частотой 10 кГц)
Код программы:

Код: Выделить всё

  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);  // тактирование таймера
  TIM_TimeBaseInitTypeDef base_timer;  
  TIM_TimeBaseStructInit(&base_timer);  
  /* Делитель учитывается как TIM_Prescaler + 1, поэтому отнимаем 1 */  
  base_timer.TIM_Prescaler = 100 - 1;  
  base_timer.TIM_Period = 10;  
  TIM_TimeBaseInit(TIM4, &base_timer);  
  TIM_ITConfig(TIM4, TIM_IT_Update, ENABLE);  
  TIM_Cmd(TIM4, ENABLE);  
  NVIC_EnableIRQ(TIM4_IRQn);

//прерывание таймера:
 void TIM4_IRQHandler()
{
  if (TIM_GetITStatus(TIM4, TIM_IT_Update) != RESET)
  {
      TIM_ClearITPendingBit(TIM4, TIM_IT_Update);
 
      if (x1==0) 
        {
        GPIO_WriteBit(GPIOA, GPIO_Pin_12, Bit_SET);          
        x1=1;
        }
      else
        {
        GPIO_WriteBit(GPIOA, GPIO_Pin_12, Bit_RESET);          
        x1=0;
        } 
  } 

На железе частота 4,5 кГц.

Сморим настройки источника тактовой частоты в библиотеки system_stm32f10x.c:

Код: Выделить всё

/*!< Uncomment the line corresponding to the desired System clock (SYSCLK)
   frequency (after reset the HSI is used as SYSCLK source)
   
   IMPORTANT NOTE:
   ============== 
   1. After each device reset the HSI is used as System clock source.

   2. Please make sure that the selected System clock doesn't exceed your device's
      maximum frequency.
      
   3. If none of the define below is enabled, the HSI is used as System clock
    source.

   4. The System clock configuration functions provided within this file assume that:
        - For Low, Medium and High density Value line devices an external 8MHz 
          crystal is used to drive the System clock.
        - For Low, Medium and High density devices an external 8MHz crystal is
          used to drive the System clock.
        - For Connectivity line devices an external 25MHz crystal is used to drive
          the System clock.
     If you are using different crystal you have to adapt those functions accordingly.
    */
    
#if defined (STM32F10X_LD_VL) || (defined STM32F10X_MD_VL) || (defined STM32F10X_HD_VL)
 #define SYSCLK_FREQ_HSE    HSE_VALUE 
/* #define SYSCLK_FREQ_24MHz  24000000 */
#else
 #define SYSCLK_FREQ_HSE    HSE_VALUE  // - [b]вот это наш источник[/b]
/* #define SYSCLK_FREQ_24MHz  24000000 */
/* #define SYSCLK_FREQ_36MHz  36000000 */
/* #define SYSCLK_FREQ_48MHz  48000000 */
/* #define SYSCLK_FREQ_56MHz  56000000 */
/* #define SYSCLK_FREQ_72MHz  72000000 */
#endif

тра-ля-ля, обработка #define в той же библиотеки system_stm32f10x.c:

Код: Выделить всё

#ifdef SYSCLK_FREQ_HSE
/**
  * @brief  Selects HSE as System clock source and configure HCLK, PCLK2
  *         and PCLK1 prescalers.
  * @note   This function should be used only after reset.
  * @param  None
  * @retval None
  */
static void SetSysClockToHSE(void)
{
  __IO uint32_t StartUpCounter = 0, HSEStatus = 0;
  
  /* SYSCLK, HCLK, PCLK2 and PCLK1 configuration ---------------------------*/    
  /* Enable HSE */    
  RCC->CR |= ((uint32_t)RCC_CR_HSEON);
 
  /* Wait till HSE is ready and if Time out is reached exit */
  do
  {
    HSEStatus = RCC->CR & RCC_CR_HSERDY;
    StartUpCounter++;  
  } while((HSEStatus == 0) && (StartUpCounter != HSE_STARTUP_TIMEOUT));

  if ((RCC->CR & RCC_CR_HSERDY) != RESET)
  {
    HSEStatus = (uint32_t)0x01;
  }
  else
  {
    HSEStatus = (uint32_t)0x00;
  }  

  if (HSEStatus == (uint32_t)0x01)
  {

#if !defined STM32F10X_LD_VL && !defined STM32F10X_MD_VL && !defined STM32F10X_HD_VL
    /* Enable Prefetch Buffer */
    FLASH->ACR |= FLASH_ACR_PRFTBE;

    /* Flash 0 wait state */
    FLASH->ACR &= (uint32_t)((uint32_t)~FLASH_ACR_LATENCY);

#ifndef STM32F10X_CL
    FLASH->ACR |= (uint32_t)FLASH_ACR_LATENCY_0;
#else
   [b] if (HSE_VALUE <= 9000000) //было 24М[/b]
	{
      FLASH->ACR |= (uint32_t)FLASH_ACR_LATENCY_0;
	}
	else
	{
      FLASH->ACR |= (uint32_t)FLASH_ACR_LATENCY_1;
	}
#endif /* STM32F10X_CL */
#endif
 
    /* HCLK = SYSCLK */
    RCC->CFGR |= (uint32_t)RCC_CFGR_HPRE_DIV1;
      
    /* PCLK2 = HCLK */
    RCC->CFGR |= (uint32_t)RCC_CFGR_PPRE2_DIV1;
    
    /* PCLK1 = HCLK */
    RCC->CFGR |= (uint32_t)RCC_CFGR_PPRE1_DIV1;
    
    /* Select HSE as system clock source */
    RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_SW));
    RCC->CFGR |= (uint32_t)RCC_CFGR_SW_HSE;    

    /* Wait till HSE is used as system clock source */
    while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS) != (uint32_t)0x04)
    {
    }
  }
  else
  { /* If HSE fails to start-up, the application will have wrong clock 
         configuration. User can add here some code to deal with this error */
  }  
}

В заголовочном файле stm32f10x.h было изменено следующее:

Код: Выделить всё

#if !defined (STM32F10X_LD) && !defined (STM32F10X_LD_VL) && !defined (STM32F10X_MD) && !defined (STM32F10X_MD_VL) && !defined (STM32F10X_HD) && !defined (STM32F10X_HD_VL) && !defined (STM32F10X_XL) && !defined (STM32F10X_CL) 
  /* #define STM32F10X_LD */     /*!< STM32F10X_LD: STM32 Low density devices */
  /* #define STM32F10X_LD_VL */  /*!< STM32F10X_LD_VL: STM32 Low density Value Line devices */  
  /* #define STM32F10X_MD */     /*!< STM32F10X_MD: STM32 Medium density devices */
  /* #define STM32F10X_MD_VL */  /*!< STM32F10X_MD_VL: STM32 Medium density Value Line devices */  
  /* #define STM32F10X_HD */     /*!< STM32F10X_HD: STM32 High density devices */
  /* #define STM32F10X_HD_VL */  /*!< STM32F10X_HD_VL: STM32 High density value line devices */  
  /* #define STM32F10X_XL */     /*!< STM32F10X_XL: STM32 XL-density devices */
  #define STM32F10X_CL      //!< STM32F10X_CL: STM32 Connectivity line devices  [b]Расскоментирован[/b] 
#endif

....

#if !defined  HSE_VALUE
 #ifdef STM32F10X_CL   
  #define HSE_VALUE    ((uint32_t)10000000) //!< Value of the External oscillator in Hz  [b] Было 24 МГц [/b] 
 #else 
  #define HSE_VALUE    ((uint32_t)8000000) /*!< Value of the External oscillator in Hz */
 #endif /* STM32F10X_CL */
#endif /* HSE_VALUE */

Есть ли принципиальные ошибки?
Почему не работает?