stm32 HAL初始化分析

时钟初始化HAL_Init

首先运行初始化，代码再stm32h7xx_hal.c中

stm32h7xx_hal.c

HAL_StatusTypeDef HAL_Init(void)
{
uint32_t common_system_clock;
由于使用h7，部分型号带双核，这个是双核时的条件编译
#if defined(DUAL_CORE) && defined(CORE_CM4)
   /* Configure Cortex-M4 Instruction cache through ART accelerator */
   __HAL_RCC_ART_CLK_ENABLE();                   /* Enable the Cortex-M4 ART Clock */
   __HAL_ART_CONFIG_BASE_ADDRESS(0x08100000UL);  /* Configure the Cortex-M4 ART Base address to the Flash Bank 2 : */
   __HAL_ART_ENABLE();                           /* Enable the Cortex-M4 ART */
#endif /* DUAL_CORE &&  CORE_CM4 */

//设置中断优先级分组4，抢占0~15，子0
  /* Set Interrupt Group Priority */
  HAL_NVIC_SetPriorityGrouping(NVIC_PRIORITYGROUP_4);

//更新全局变量
  /* Update the SystemCoreClock global variable */
#if defined(RCC_D1CFGR_D1CPRE)
  common_system_clock = HAL_RCC_GetSysClockFreq() >> ((D1CorePrescTable[(RCC->D1CFGR & RCC_D1CFGR_D1CPRE)>> RCC_D1CFGR_D1CPRE_Pos]) & 0x1FU);
#else
  common_system_clock = HAL_RCC_GetSysClockFreq() >> ((D1CorePrescTable[(RCC->CDCFGR1 & RCC_CDCFGR1_CDCPRE)>> RCC_CDCFGR1_CDCPRE_Pos]) & 0x1FU);
#endif

//更新时钟全局变量SystemCoreClock
  /* Update the SystemD2Clock global variable */
#if defined(RCC_D1CFGR_HPRE)
  SystemD2Clock = (common_system_clock >> ((D1CorePrescTable[(RCC->D1CFGR & RCC_D1CFGR_HPRE)>> RCC_D1CFGR_HPRE_Pos]) & 0x1FU));
#else
  SystemD2Clock = (common_system_clock >> ((D1CorePrescTable[(RCC->CDCFGR1 & RCC_CDCFGR1_HPRE)>> RCC_CDCFGR1_HPRE_Pos]) & 0x1FU));
#endif

#if defined(DUAL_CORE) && defined(CORE_CM4)
  SystemCoreClock = SystemD2Clock;
#else
  SystemCoreClock = common_system_clock;
#endif /* DUAL_CORE && CORE_CM4 */

//关键在于HAL_InitTick(TICK_INT_PRIORITY)函数，初始化嘀嗒定时器
  /* Use systick as time base source and configure 1ms tick (default clock after Reset is HSI) */
  if(HAL_InitTick(TICK_INT_PRIORITY) != HAL_OK)
  {
    return HAL_ERROR;
  }

  /* Init the low level hardware */
  HAL_MspInit();

  /* Return function status */
  return HAL_OK;
}
//*********************************************************************
__weak HAL_StatusTypeDef HAL_InitTick(uint32_t TickPriority)
{
  /* Check uwTickFreq for MisraC 2012 (even if uwTickFreq is a enum type that don't take the value zero)*/
  if((uint32_t)uwTickFreq == 0UL)
  {
    return HAL_ERROR;
  }

    /* Configure the SysTick to have interrupt in 1ms time basis*/
    if (HAL_SYSTICK_Config(SystemCoreClock / (1000UL / (uint32_t)uwTickFreq)) > 0U)
    {
      return HAL_ERROR;
    }

  /* Configure the SysTick IRQ priority */
  if (TickPriority < (1UL << __NVIC_PRIO_BITS))
  {
    HAL_NVIC_SetPriority(SysTick_IRQn, TickPriority, 0U);
    uwTickPrio = TickPriority;
  }
  else
  {
    return HAL_ERROR;
  }

  /* Return function status */
  return HAL_OK;
}

stm32h7xx_hal_cortex.c

uint32_t HAL_SYSTICK_Config(uint32_t TicksNumb)
{
   return SysTick_Config(TicksNumb);
}

core_cm7.h

__STATIC_INLINE uint32_t SysTick_Config(uint32_t ticks)
{
  if ((ticks - 1UL) > SysTick_LOAD_RELOAD_Msk)
  {
    return (1UL);                                                   /* Reload value impossible */
  }

  SysTick->LOAD  = (uint32_t)(ticks - 1UL);                         /* set reload register */
  NVIC_SetPriority (SysTick_IRQn, (1UL << __NVIC_PRIO_BITS) - 1UL); /* set Priority for Systick Interrupt */
  SysTick->VAL   = 0UL;                                             /* Load the SysTick Counter Value */
  SysTick->CTRL  = SysTick_CTRL_CLKSOURCE_Msk |
                   SysTick_CTRL_TICKINT_Msk   |
                   SysTick_CTRL_ENABLE_Msk;                         /* Enable SysTick IRQ and SysTick Timer */
  return (0UL);                                                     /* Function successful */
}

分析：
由HAL_InitTick函数会一步步到SysTick_Config，其中SysTick_Config再对应的内核文件core_cm7.h中，并且SysTick_Config会将嘀嗒定时器配置为1kHz。
会配置优先级HAL_NVIC_SetPriority(SysTick_IRQn, TickPriority, 0U);其中TickPriority的参数TICK_INT_PRIORITY是宏定义，在stm32h7xx_hal_conf.h文件内可以找到

初始化代码继续讲解

前面SystemCoreClock一直使用内部高速时钟HSI–64M，并且初始化了嘀嗒定时器
后面开始各种PLL时钟初始化SystemClock_Config函数

void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Supply configuration update enable
  */
  HAL_PWREx_ConfigSupply(PWR_LDO_SUPPLY);
  /** Configure the main internal regulator output voltage
  */
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE0);

  while(!__HAL_PWR_GET_FLAG(PWR_FLAG_VOSRDY)) {}
  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI48|RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.HSI48State = RCC_HSI48_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLM = 5;
  RCC_OscInitStruct.PLL.PLLN = 192;
  RCC_OscInitStruct.PLL.PLLP = 2;
  RCC_OscInitStruct.PLL.PLLQ = 2;
  RCC_OscInitStruct.PLL.PLLR = 2;
  RCC_OscInitStruct.PLL.PLLRGE = RCC_PLL1VCIRANGE_2;
  RCC_OscInitStruct.PLL.PLLVCOSEL = RCC_PLL1VCOWIDE;
  RCC_OscInitStruct.PLL.PLLFRACN = 0;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }
  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2
                              |RCC_CLOCKTYPE_D3PCLK1|RCC_CLOCKTYPE_D1PCLK1;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.SYSCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_HCLK_DIV2;
  RCC_ClkInitStruct.APB3CLKDivider = RCC_APB3_DIV2;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_APB1_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_APB2_DIV2;
  RCC_ClkInitStruct.APB4CLKDivider = RCC_APB4_DIV2;

	//重点
  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4) != HAL_OK)
  {
    Error_Handler();
  }
}

重点在函数HAL_RCC_ClockConfig中，在文件stm32h7xx_hal_rcc.c中可以找到，由于函数太长，就不全放了
其中重点在下面这段

  /* Update the SystemCoreClock global variable */
#if defined(RCC_D1CFGR_D1CPRE)
  common_system_clock = HAL_RCC_GetSysClockFreq() >> ((D1CorePrescTable[(RCC->D1CFGR & RCC_D1CFGR_D1CPRE)>> RCC_D1CFGR_D1CPRE_Pos]) & 0x1FU);
#else
  common_system_clock = HAL_RCC_GetSysClockFreq() >> ((D1CorePrescTable[(RCC->CDCFGR1 & RCC_CDCFGR1_CDCPRE)>> RCC_CDCFGR1_CDCPRE_Pos]) & 0x1FU);
#endif

#if defined(RCC_D1CFGR_HPRE)
  SystemD2Clock = (common_system_clock >> ((D1CorePrescTable[(RCC->D1CFGR & RCC_D1CFGR_HPRE)>> RCC_D1CFGR_HPRE_Pos]) & 0x1FU));
#else
  SystemD2Clock = (common_system_clock >> ((D1CorePrescTable[(RCC->CDCFGR1 & RCC_CDCFGR1_HPRE)>> RCC_CDCFGR1_HPRE_Pos]) & 0x1FU));
#endif

#if defined(DUAL_CORE) && defined(CORE_CM4)
  SystemCoreClock = SystemD2Clock;
#else
  SystemCoreClock = common_system_clock;
#endif /* DUAL_CORE && CORE_CM4 */

  /* Configure the source of time base considering new system clocks settings*/
  halstatus = HAL_InitTick (uwTickPrio);

在这里我们更新了系统时钟SystemCoreClock变量，并且再次调用HAL_InitTick函数进行更新

注意：HAL_InitTick函数我们总共调用两次

• 第一次是在HAL_Init时，那时我们还是用的HSI-64M
• 第二次就是在这里，这是我们的时钟就是HSE了，具体频率看配置400/480

至此基础初始化完成

验证：相关变量的查看

在这里：

• SystemCoreClock由最开始定义的64M变成了480M
• SysTick->LOAD 变成了 ( 480M/1000-1 )
• SysTick->VAL值改变看不出来，由于不是us定时，我们在下面测

我们换个代码专门测一下Systick->VAL的变化

可以看到延时500us，嘀嗒定时器的值减少了一半，是符合预期的

版权声明：本文为CSDN博主「gxt_kt」的原创文章，遵循CC 4.0 BY-SA版权协议，转载请附上原文出处链接及本声明。
原文链接：https://blog.csdn.net/my_id_kt/article/details/122975133

stm32 HAL初始化分析

时钟初始化HAL_Init

首先运行初始化，代码再stm32h7xx_hal.c中

stm32h7xx_hal.c

HAL_StatusTypeDef HAL_Init(void)
{
uint32_t common_system_clock;
由于使用h7，部分型号带双核，这个是双核时的条件编译
#if defined(DUAL_CORE) && defined(CORE_CM4)
   /* Configure Cortex-M4 Instruction cache through ART accelerator */
   __HAL_RCC_ART_CLK_ENABLE();                   /* Enable the Cortex-M4 ART Clock */
   __HAL_ART_CONFIG_BASE_ADDRESS(0x08100000UL);  /* Configure the Cortex-M4 ART Base address to the Flash Bank 2 : */
   __HAL_ART_ENABLE();                           /* Enable the Cortex-M4 ART */
#endif /* DUAL_CORE &&  CORE_CM4 */

//设置中断优先级分组4，抢占0~15，子0
  /* Set Interrupt Group Priority */
  HAL_NVIC_SetPriorityGrouping(NVIC_PRIORITYGROUP_4);

//更新全局变量
  /* Update the SystemCoreClock global variable */
#if defined(RCC_D1CFGR_D1CPRE)
  common_system_clock = HAL_RCC_GetSysClockFreq() >> ((D1CorePrescTable[(RCC->D1CFGR & RCC_D1CFGR_D1CPRE)>> RCC_D1CFGR_D1CPRE_Pos]) & 0x1FU);
#else
  common_system_clock = HAL_RCC_GetSysClockFreq() >> ((D1CorePrescTable[(RCC->CDCFGR1 & RCC_CDCFGR1_CDCPRE)>> RCC_CDCFGR1_CDCPRE_Pos]) & 0x1FU);
#endif

//更新时钟全局变量SystemCoreClock
  /* Update the SystemD2Clock global variable */
#if defined(RCC_D1CFGR_HPRE)
  SystemD2Clock = (common_system_clock >> ((D1CorePrescTable[(RCC->D1CFGR & RCC_D1CFGR_HPRE)>> RCC_D1CFGR_HPRE_Pos]) & 0x1FU));
#else
  SystemD2Clock = (common_system_clock >> ((D1CorePrescTable[(RCC->CDCFGR1 & RCC_CDCFGR1_HPRE)>> RCC_CDCFGR1_HPRE_Pos]) & 0x1FU));
#endif

#if defined(DUAL_CORE) && defined(CORE_CM4)
  SystemCoreClock = SystemD2Clock;
#else
  SystemCoreClock = common_system_clock;
#endif /* DUAL_CORE && CORE_CM4 */

//关键在于HAL_InitTick(TICK_INT_PRIORITY)函数，初始化嘀嗒定时器
  /* Use systick as time base source and configure 1ms tick (default clock after Reset is HSI) */
  if(HAL_InitTick(TICK_INT_PRIORITY) != HAL_OK)
  {
    return HAL_ERROR;
  }

  /* Init the low level hardware */
  HAL_MspInit();

  /* Return function status */
  return HAL_OK;
}
//*********************************************************************
__weak HAL_StatusTypeDef HAL_InitTick(uint32_t TickPriority)
{
  /* Check uwTickFreq for MisraC 2012 (even if uwTickFreq is a enum type that don't take the value zero)*/
  if((uint32_t)uwTickFreq == 0UL)
  {
    return HAL_ERROR;
  }

    /* Configure the SysTick to have interrupt in 1ms time basis*/
    if (HAL_SYSTICK_Config(SystemCoreClock / (1000UL / (uint32_t)uwTickFreq)) > 0U)
    {
      return HAL_ERROR;
    }

  /* Configure the SysTick IRQ priority */
  if (TickPriority < (1UL << __NVIC_PRIO_BITS))
  {
    HAL_NVIC_SetPriority(SysTick_IRQn, TickPriority, 0U);
    uwTickPrio = TickPriority;
  }
  else
  {
    return HAL_ERROR;
  }

  /* Return function status */
  return HAL_OK;
}

stm32h7xx_hal_cortex.c

uint32_t HAL_SYSTICK_Config(uint32_t TicksNumb)
{
   return SysTick_Config(TicksNumb);
}

core_cm7.h

__STATIC_INLINE uint32_t SysTick_Config(uint32_t ticks)
{
  if ((ticks - 1UL) > SysTick_LOAD_RELOAD_Msk)
  {
    return (1UL);                                                   /* Reload value impossible */
  }

  SysTick->LOAD  = (uint32_t)(ticks - 1UL);                         /* set reload register */
  NVIC_SetPriority (SysTick_IRQn, (1UL << __NVIC_PRIO_BITS) - 1UL); /* set Priority for Systick Interrupt */
  SysTick->VAL   = 0UL;                                             /* Load the SysTick Counter Value */
  SysTick->CTRL  = SysTick_CTRL_CLKSOURCE_Msk |
                   SysTick_CTRL_TICKINT_Msk   |
                   SysTick_CTRL_ENABLE_Msk;                         /* Enable SysTick IRQ and SysTick Timer */
  return (0UL);                                                     /* Function successful */
}

分析：
由HAL_InitTick函数会一步步到SysTick_Config，其中SysTick_Config再对应的内核文件core_cm7.h中，并且SysTick_Config会将嘀嗒定时器配置为1kHz。
会配置优先级HAL_NVIC_SetPriority(SysTick_IRQn, TickPriority, 0U);其中TickPriority的参数TICK_INT_PRIORITY是宏定义，在stm32h7xx_hal_conf.h文件内可以找到

初始化代码继续讲解

前面SystemCoreClock一直使用内部高速时钟HSI–64M，并且初始化了嘀嗒定时器
后面开始各种PLL时钟初始化SystemClock_Config函数

void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Supply configuration update enable
  */
  HAL_PWREx_ConfigSupply(PWR_LDO_SUPPLY);
  /** Configure the main internal regulator output voltage
  */
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE0);

  while(!__HAL_PWR_GET_FLAG(PWR_FLAG_VOSRDY)) {}
  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI48|RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.HSI48State = RCC_HSI48_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLM = 5;
  RCC_OscInitStruct.PLL.PLLN = 192;
  RCC_OscInitStruct.PLL.PLLP = 2;
  RCC_OscInitStruct.PLL.PLLQ = 2;
  RCC_OscInitStruct.PLL.PLLR = 2;
  RCC_OscInitStruct.PLL.PLLRGE = RCC_PLL1VCIRANGE_2;
  RCC_OscInitStruct.PLL.PLLVCOSEL = RCC_PLL1VCOWIDE;
  RCC_OscInitStruct.PLL.PLLFRACN = 0;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }
  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2
                              |RCC_CLOCKTYPE_D3PCLK1|RCC_CLOCKTYPE_D1PCLK1;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.SYSCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_HCLK_DIV2;
  RCC_ClkInitStruct.APB3CLKDivider = RCC_APB3_DIV2;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_APB1_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_APB2_DIV2;
  RCC_ClkInitStruct.APB4CLKDivider = RCC_APB4_DIV2;

	//重点
  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4) != HAL_OK)
  {
    Error_Handler();
  }
}

重点在函数HAL_RCC_ClockConfig中，在文件stm32h7xx_hal_rcc.c中可以找到，由于函数太长，就不全放了
其中重点在下面这段

  /* Update the SystemCoreClock global variable */
#if defined(RCC_D1CFGR_D1CPRE)
  common_system_clock = HAL_RCC_GetSysClockFreq() >> ((D1CorePrescTable[(RCC->D1CFGR & RCC_D1CFGR_D1CPRE)>> RCC_D1CFGR_D1CPRE_Pos]) & 0x1FU);
#else
  common_system_clock = HAL_RCC_GetSysClockFreq() >> ((D1CorePrescTable[(RCC->CDCFGR1 & RCC_CDCFGR1_CDCPRE)>> RCC_CDCFGR1_CDCPRE_Pos]) & 0x1FU);
#endif

#if defined(RCC_D1CFGR_HPRE)
  SystemD2Clock = (common_system_clock >> ((D1CorePrescTable[(RCC->D1CFGR & RCC_D1CFGR_HPRE)>> RCC_D1CFGR_HPRE_Pos]) & 0x1FU));
#else
  SystemD2Clock = (common_system_clock >> ((D1CorePrescTable[(RCC->CDCFGR1 & RCC_CDCFGR1_HPRE)>> RCC_CDCFGR1_HPRE_Pos]) & 0x1FU));
#endif

#if defined(DUAL_CORE) && defined(CORE_CM4)
  SystemCoreClock = SystemD2Clock;
#else
  SystemCoreClock = common_system_clock;
#endif /* DUAL_CORE && CORE_CM4 */

  /* Configure the source of time base considering new system clocks settings*/
  halstatus = HAL_InitTick (uwTickPrio);

在这里我们更新了系统时钟SystemCoreClock变量，并且再次调用HAL_InitTick函数进行更新

注意：HAL_InitTick函数我们总共调用两次

• 第一次是在HAL_Init时，那时我们还是用的HSI-64M
• 第二次就是在这里，这是我们的时钟就是HSE了，具体频率看配置400/480

至此基础初始化完成

验证：相关变量的查看

在这里：

• SystemCoreClock由最开始定义的64M变成了480M
• SysTick->LOAD 变成了 ( 480M/1000-1 )
• SysTick->VAL值改变看不出来，由于不是us定时，我们在下面测

我们换个代码专门测一下Systick->VAL的变化

可以看到延时500us，嘀嗒定时器的值减少了一半，是符合预期的

版权声明：本文为CSDN博主「gxt_kt」的原创文章，遵循CC 4.0 BY-SA版权协议，转载请附上原文出处链接及本声明。
原文链接：https://blog.csdn.net/my_id_kt/article/details/122975133