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stm32基于RTos的boot跳转问题,中断向量表的修改时机

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tpgf|  楼主 | 2024-3-13 13:06 | 只看该作者 回帖奖励 |倒序浏览 |阅读模式
1.如果使用的是stm32芯片,且App带了操作系统,如RTOS,并且使用了boot

因为boot跳转App后,需要重新定位中断向量表和重新打开全局中断,这个时候,如果打开时机不对,就会出现 osErrorISR 的报错,这个错误明显是和中断相关的。具体是因为在汇编程序startup_stm32h7b0xx.s中,在跳转main函数之前,会调用SystemInit函数,而在这个函数调用时就应该把中断初始化了,而不是像以前裸机那样,在main函数中重定向中断向量表

先看一般情况下我们的跳转后的向量表和中断开关操作:在main函数中完成

int main(void)
{
    /*中断向量表的重新定义和打开全局中断*/
    SCB->VTOR = 0x08000000 | 0x8000;
    __enable_irq();

    /*******/
}
再看startup_stm32h7b0xx.s中对SystemInit的调用,下面代码的最后一句

  .section  .text.Reset_Handler
  .weak  Reset_Handler
  .type  Reset_Handler, %function
Reset_Handler:  
  ldr   sp, =_estack      /* set stack pointer */

/* Call the clock system initialization function.*/
  bl  SystemInit
如果在这个函数中不重定向中断向量表,而在main函数中定向,在程序执行到main之前,发生中断,就会可能导致出错。

解决办法如下:

1.找到system_stm32h7xx.c这个文件,在文件中找到SystemInit函数,函数的最后两句如下

#if defined(USER_VECT_TAB_ADDRESS)
  SCB->VTOR = VECT_TAB_BASE_ADDRESS | VECT_TAB_OFFSET;
#endif /* USER_VECT_TAB_ADDRESS */

注释:/* Vector Table Relocation in Internal D1 AXI-RAM or in Internal FLASH */

意思为重新定位中断向量表,但是这个重新定位被全局宏USER_VECT_TAB_ADDRESS管控

void SystemInit (void)
{
#if defined (DATA_IN_D2_SRAM)
__IO uint32_t tmpreg;
#endif /* DATA_IN_D2_SRAM */

  /* FPU settings ------------------------------------------------------------*/
  #if (__FPU_PRESENT == 1) && (__FPU_USED == 1)
    SCB->CPACR |= ((3UL << (10*2))|(3UL << (11*2)));  /* set CP10 and CP11 Full Access */
  #endif
  /* Reset the RCC clock configuration to the default reset state ------------*/

   /* Increasing the CPU frequency */
  if(FLASH_LATENCY_DEFAULT  > (READ_BIT((FLASH->ACR), FLASH_ACR_LATENCY)))
  {
    /* Program the new number of wait states to the LATENCY bits in the FLASH_ACR register */
    MODIFY_REG(FLASH->ACR, FLASH_ACR_LATENCY, (uint32_t)(FLASH_LATENCY_DEFAULT));
  }

  /* Set HSION bit */
  RCC->CR |= RCC_CR_HSION;

  /* Reset CFGR register */
  RCC->CFGR = 0x00000000;

  /* Reset HSEON, HSECSSON, CSION, HSI48ON, CSIKERON, PLL1ON, PLL2ON and PLL3ON bits */
  RCC->CR &= 0xEAF6ED7FU;

   /* Decreasing the number of wait states because of lower CPU frequency */
  if(FLASH_LATENCY_DEFAULT  < (READ_BIT((FLASH->ACR), FLASH_ACR_LATENCY)))
  {
    /* Program the new number of wait states to the LATENCY bits in the FLASH_ACR register */
    MODIFY_REG(FLASH->ACR, FLASH_ACR_LATENCY, (uint32_t)(FLASH_LATENCY_DEFAULT));
  }

#if defined(D3_SRAM_BASE)
  /* Reset D1CFGR register */
  RCC->D1CFGR = 0x00000000;

  /* Reset D2CFGR register */
  RCC->D2CFGR = 0x00000000;

  /* Reset D3CFGR register */
  RCC->D3CFGR = 0x00000000;
#else
  /* Reset CDCFGR1 register */
  RCC->CDCFGR1 = 0x00000000;

  /* Reset CDCFGR2 register */
  RCC->CDCFGR2 = 0x00000000;

  /* Reset SRDCFGR register */
  RCC->SRDCFGR = 0x00000000;
#endif
  /* Reset PLLCKSELR register */
  RCC->PLLCKSELR = 0x02020200;

  /* Reset PLLCFGR register */
  RCC->PLLCFGR = 0x01FF0000;
  /* Reset PLL1DIVR register */
  RCC->PLL1DIVR = 0x01010280;
  /* Reset PLL1FRACR register */
  RCC->PLL1FRACR = 0x00000000;

  /* Reset PLL2DIVR register */
  RCC->PLL2DIVR = 0x01010280;

  /* Reset PLL2FRACR register */

  RCC->PLL2FRACR = 0x00000000;
  /* Reset PLL3DIVR register */
  RCC->PLL3DIVR = 0x01010280;

  /* Reset PLL3FRACR register */
  RCC->PLL3FRACR = 0x00000000;

  /* Reset HSEBYP bit */
  RCC->CR &= 0xFFFBFFFFU;

  /* Disable all interrupts */
  RCC->CIER = 0x00000000;

#if (STM32H7_DEV_ID == 0x450UL)
  /* dual core CM7 or single core line */
  if((DBGMCU->IDCODE & 0xFFFF0000U) < 0x20000000U)
  {
    /* if stm32h7 revY*/
    /* Change  the switch matrix read issuing capability to 1 for the AXI SRAM target (Target 7) */
    *((__IO uint32_t*)0x51008108) = 0x000000001U;
  }
#endif /* STM32H7_DEV_ID */

#if defined(DATA_IN_D2_SRAM)
  /* in case of initialized data in D2 SRAM (AHB SRAM), enable the D2 SRAM clock (AHB SRAM clock) */
#if defined(RCC_AHB2ENR_D2SRAM3EN)
  RCC->AHB2ENR |= (RCC_AHB2ENR_D2SRAM1EN | RCC_AHB2ENR_D2SRAM2EN | RCC_AHB2ENR_D2SRAM3EN);
#elif defined(RCC_AHB2ENR_D2SRAM2EN)
  RCC->AHB2ENR |= (RCC_AHB2ENR_D2SRAM1EN | RCC_AHB2ENR_D2SRAM2EN);
#else
  RCC->AHB2ENR |= (RCC_AHB2ENR_AHBSRAM1EN | RCC_AHB2ENR_AHBSRAM2EN);
#endif /* RCC_AHB2ENR_D2SRAM3EN */

  tmpreg = RCC->AHB2ENR;
  (void) tmpreg;
#endif /* DATA_IN_D2_SRAM */

#if defined(DUAL_CORE) && defined(CORE_CM4)
  /* Configure the Vector Table location add offset address for cortex-M4 ------------------*/
#if defined(USER_VECT_TAB_ADDRESS)
  SCB->VTOR = VECT_TAB_BASE_ADDRESS | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal D2 AXI-RAM or in Internal FLASH */
#endif /* USER_VECT_TAB_ADDRESS */

#else
  /*
   * Disable the FMC bank1 (enabled after reset).
   * This, prevents CPU speculation access on this bank which blocks the use of FMC during
   * 24us. During this time the others FMC master (such as LTDC) cannot use it!
   */
  FMC_Bank1_R->BTCR[0] = 0x000030D2;

  /* Configure the Vector Table location -------------------------------------*/
#if defined(USER_VECT_TAB_ADDRESS)
  SCB->VTOR = VECT_TAB_BASE_ADDRESS | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal D1 AXI-RAM or in Internal FLASH */
#endif /* USER_VECT_TAB_ADDRESS */

#endif /*DUAL_CORE && CORE_CM4*/
}

2.只需要打开这USER_VECT_TAB_ADDRESS宏即可

继续在这个文件中的前面找到被注释的这个宏,然后修改重定位的偏移VECT_TAB_OFFSET即可,下面的代码是我修改后的,VECT_TAB_OFFSET根据自己的实际情况修改

/************************* Miscellaneous Configuration ************************/
/*!< Uncomment the following line if you need to use initialized data in D2 domain SRAM (AHB SRAM) */
/* #define DATA_IN_D2_SRAM */

/* Note: Following vector table addresses must be defined in line with linker
         configuration. */
/*!< Uncomment the following line if you need to relocate the vector table
     anywhere in FLASH BANK1 or AXI SRAM, else the vector table is kept at the automatic
     remap of boot address selected */
#define USER_VECT_TAB_ADDRESS

#if defined(USER_VECT_TAB_ADDRESS)
#if defined(DUAL_CORE) && defined(CORE_CM4)
/*!< Uncomment the following line if you need to relocate your vector Table
     in D2 AXI SRAM else user remap will be done in FLASH BANK2. */
/* #define VECT_TAB_SRAM */
#if defined(VECT_TAB_SRAM)
#define VECT_TAB_BASE_ADDRESS   D2_AXISRAM_BASE   /*!< Vector Table base address field.
                                                       This value must be a multiple of 0x400. */
#define VECT_TAB_OFFSET         0x00000000U       /*!< Vector Table base offset field.
                                                       This value must be a multiple of 0x400. */
#else
#define VECT_TAB_BASE_ADDRESS   FLASH_BANK2_BASE  /*!< Vector Table base address field.
                                                       This value must be a multiple of 0x400. */
#define VECT_TAB_OFFSET         0x00000000U       /*!< Vector Table base offset field.
                                                       This value must be a multiple of 0x400. */
#endif /* VECT_TAB_SRAM */
#else
/*!< Uncomment the following line if you need to relocate your vector Table
     in D1 AXI SRAM else user remap will be done in FLASH BANK1. */
/* #define VECT_TAB_SRAM */
#if defined(VECT_TAB_SRAM)
#define VECT_TAB_BASE_ADDRESS   D1_AXISRAM_BASE   /*!< Vector Table base address field.
                                                       This value must be a multiple of 0x400. */
#define VECT_TAB_OFFSET         0x00000000U       /*!< Vector Table base offset field.
                                                       This value must be a multiple of 0x400. */
#else
#define VECT_TAB_BASE_ADDRESS   FLASH_BANK1_BASE  /*!< Vector Table base address field.
                                                       This value must be a multiple of 0x400. */
#define VECT_TAB_OFFSET         0x00008000U       /*!< Vector Table base offset field.
                                                       This value must be a multiple of 0x400. */
#endif /* VECT_TAB_SRAM */
#endif /* DUAL_CORE && CORE_CM4 */
#endif /* USER_VECT_TAB_ADDRESS */
/******************************************************************************/

3.修改中断向量表之后,即可打开中断

在SystemInit函数的最后一句添加__enable_irq();

整个文件修改后如下,仅供参靠。

/**
  ******************************************************************************
  * @file    system_stm32h7xx.c
  * @author  MCD Application Team
  * @brief   CMSIS Cortex-Mx Device Peripheral Access Layer System Source File.
  *
  *   This file provides two functions and one global variable to be called from
  *   user application:
  *      - SystemInit(): This function is called at startup just after reset and
  *                      before branch to main program. This call is made inside
  *                      the "startup_stm32h7xx.s" file.
  *
  *      - SystemCoreClock variable: Contains the core clock, it can be used
  *                                  by the user application to setup the SysTick
  *                                  timer or configure other parameters.
  *
  *      - SystemCoreClockUpdate(): Updates the variable SystemCoreClock and must
  *                                 be called whenever the core clock is changed
  *                                 during program execution.
  *
  *
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2017 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */

/** @addtogroup CMSIS
  * @{
  */

/** @addtogroup stm32h7xx_system
  * @{
  */

/** @addtogroup STM32H7xx_System_Private_Includes
  * @{
  */

#include "stm32h7xx.h"
#include <math.h>

#if !defined  (HSE_VALUE)
#define HSE_VALUE    ((uint32_t)25000000) /*!< Value of the External oscillator in Hz */
#endif /* HSE_VALUE */

#if !defined  (CSI_VALUE)
  #define CSI_VALUE    ((uint32_t)4000000) /*!< Value of the Internal oscillator in Hz*/
#endif /* CSI_VALUE */

#if !defined  (HSI_VALUE)
  #define HSI_VALUE    ((uint32_t)64000000) /*!< Value of the Internal oscillator in Hz*/
#endif /* HSI_VALUE */


/**
  * @}
  */

/** @addtogroup STM32H7xx_System_Private_TypesDefinitions
  * @{
  */

/**
  * @}
  */

/** @addtogroup STM32H7xx_System_Private_Defines
  * @{
  */

/************************* Miscellaneous Configuration ************************/
/*!< Uncomment the following line if you need to use initialized data in D2 domain SRAM (AHB SRAM) */
/* #define DATA_IN_D2_SRAM */

/* Note: Following vector table addresses must be defined in line with linker
         configuration. */
/*!< Uncomment the following line if you need to relocate the vector table
     anywhere in FLASH BANK1 or AXI SRAM, else the vector table is kept at the automatic
     remap of boot address selected */
#define USER_VECT_TAB_ADDRESS

#if defined(USER_VECT_TAB_ADDRESS)
#if defined(DUAL_CORE) && defined(CORE_CM4)
/*!< Uncomment the following line if you need to relocate your vector Table
     in D2 AXI SRAM else user remap will be done in FLASH BANK2. */
/* #define VECT_TAB_SRAM */
#if defined(VECT_TAB_SRAM)
#define VECT_TAB_BASE_ADDRESS   D2_AXISRAM_BASE   /*!< Vector Table base address field.
                                                       This value must be a multiple of 0x400. */
#define VECT_TAB_OFFSET         0x00000000U       /*!< Vector Table base offset field.
                                                       This value must be a multiple of 0x400. */
#else
#define VECT_TAB_BASE_ADDRESS   FLASH_BANK2_BASE  /*!< Vector Table base address field.
                                                       This value must be a multiple of 0x400. */
#define VECT_TAB_OFFSET         0x00000000U       /*!< Vector Table base offset field.
                                                       This value must be a multiple of 0x400. */
#endif /* VECT_TAB_SRAM */
#else
/*!< Uncomment the following line if you need to relocate your vector Table
     in D1 AXI SRAM else user remap will be done in FLASH BANK1. */
/* #define VECT_TAB_SRAM */
#if defined(VECT_TAB_SRAM)
#define VECT_TAB_BASE_ADDRESS   D1_AXISRAM_BASE   /*!< Vector Table base address field.
                                                       This value must be a multiple of 0x400. */
#define VECT_TAB_OFFSET         0x00000000U       /*!< Vector Table base offset field.
                                                       This value must be a multiple of 0x400. */
#else
#define VECT_TAB_BASE_ADDRESS   FLASH_BANK1_BASE  /*!< Vector Table base address field.
                                                       This value must be a multiple of 0x400. */
#define VECT_TAB_OFFSET         0x00008000U       /*!< Vector Table base offset field.
                                                       This value must be a multiple of 0x400. */
#endif /* VECT_TAB_SRAM */
#endif /* DUAL_CORE && CORE_CM4 */
#endif /* USER_VECT_TAB_ADDRESS */
/******************************************************************************/

/**
  * @}
  */

/** @addtogroup STM32H7xx_System_Private_Macros
  * @{
  */

/**
  * @}
  */

/** @addtogroup STM32H7xx_System_Private_Variables
  * @{
  */
  /* This variable is updated in three ways:
      1) by calling CMSIS function SystemCoreClockUpdate()
      2) by calling HAL API function HAL_RCC_GetHCLKFreq()
      3) each time HAL_RCC_ClockConfig() is called to configure the system clock frequency
         Note: If you use this function to configure the system clock; then there
               is no need to call the 2 first functions listed above, since SystemCoreClock
               variable is updated automatically.
  */
  uint32_t SystemCoreClock = 64000000;
  uint32_t SystemD2Clock = 64000000;
  const  uint8_t D1CorePrescTable[16] = {0, 0, 0, 0, 1, 2, 3, 4, 1, 2, 3, 4, 6, 7, 8, 9};

/**
  * @}
  */

/** @addtogroup STM32H7xx_System_Private_FunctionPrototypes
  * @{
  */

/**
  * @}
  */

/** @addtogroup STM32H7xx_System_Private_Functions
  * @{
  */

/**
  * @brief  Setup the microcontroller system
  *         Initialize the FPU setting and  vector table location
  *         configuration.
  * @param  None
  * @retval None
  */
void SystemInit (void)
{
#if defined (DATA_IN_D2_SRAM)
__IO uint32_t tmpreg;
#endif /* DATA_IN_D2_SRAM */

  /* FPU settings ------------------------------------------------------------*/
  #if (__FPU_PRESENT == 1) && (__FPU_USED == 1)
    SCB->CPACR |= ((3UL << (10*2))|(3UL << (11*2)));  /* set CP10 and CP11 Full Access */
  #endif
  /* Reset the RCC clock configuration to the default reset state ------------*/

   /* Increasing the CPU frequency */
  if(FLASH_LATENCY_DEFAULT  > (READ_BIT((FLASH->ACR), FLASH_ACR_LATENCY)))
  {
    /* Program the new number of wait states to the LATENCY bits in the FLASH_ACR register */
    MODIFY_REG(FLASH->ACR, FLASH_ACR_LATENCY, (uint32_t)(FLASH_LATENCY_DEFAULT));
  }

  /* Set HSION bit */
  RCC->CR |= RCC_CR_HSION;

  /* Reset CFGR register */
  RCC->CFGR = 0x00000000;

  /* Reset HSEON, HSECSSON, CSION, HSI48ON, CSIKERON, PLL1ON, PLL2ON and PLL3ON bits */
  RCC->CR &= 0xEAF6ED7FU;

   /* Decreasing the number of wait states because of lower CPU frequency */
  if(FLASH_LATENCY_DEFAULT  < (READ_BIT((FLASH->ACR), FLASH_ACR_LATENCY)))
  {
    /* Program the new number of wait states to the LATENCY bits in the FLASH_ACR register */
    MODIFY_REG(FLASH->ACR, FLASH_ACR_LATENCY, (uint32_t)(FLASH_LATENCY_DEFAULT));
  }

#if defined(D3_SRAM_BASE)
  /* Reset D1CFGR register */
  RCC->D1CFGR = 0x00000000;

  /* Reset D2CFGR register */
  RCC->D2CFGR = 0x00000000;

  /* Reset D3CFGR register */
  RCC->D3CFGR = 0x00000000;
#else
  /* Reset CDCFGR1 register */
  RCC->CDCFGR1 = 0x00000000;

  /* Reset CDCFGR2 register */
  RCC->CDCFGR2 = 0x00000000;

  /* Reset SRDCFGR register */
  RCC->SRDCFGR = 0x00000000;
#endif
  /* Reset PLLCKSELR register */
  RCC->PLLCKSELR = 0x02020200;

  /* Reset PLLCFGR register */
  RCC->PLLCFGR = 0x01FF0000;
  /* Reset PLL1DIVR register */
  RCC->PLL1DIVR = 0x01010280;
  /* Reset PLL1FRACR register */
  RCC->PLL1FRACR = 0x00000000;

  /* Reset PLL2DIVR register */
  RCC->PLL2DIVR = 0x01010280;

  /* Reset PLL2FRACR register */

  RCC->PLL2FRACR = 0x00000000;
  /* Reset PLL3DIVR register */
  RCC->PLL3DIVR = 0x01010280;

  /* Reset PLL3FRACR register */
  RCC->PLL3FRACR = 0x00000000;

  /* Reset HSEBYP bit */
  RCC->CR &= 0xFFFBFFFFU;

  /* Disable all interrupts */
  RCC->CIER = 0x00000000;

#if (STM32H7_DEV_ID == 0x450UL)
  /* dual core CM7 or single core line */
  if((DBGMCU->IDCODE & 0xFFFF0000U) < 0x20000000U)
  {
    /* if stm32h7 revY*/
    /* Change  the switch matrix read issuing capability to 1 for the AXI SRAM target (Target 7) */
    *((__IO uint32_t*)0x51008108) = 0x000000001U;
  }
#endif /* STM32H7_DEV_ID */

#if defined(DATA_IN_D2_SRAM)
  /* in case of initialized data in D2 SRAM (AHB SRAM), enable the D2 SRAM clock (AHB SRAM clock) */
#if defined(RCC_AHB2ENR_D2SRAM3EN)
  RCC->AHB2ENR |= (RCC_AHB2ENR_D2SRAM1EN | RCC_AHB2ENR_D2SRAM2EN | RCC_AHB2ENR_D2SRAM3EN);
#elif defined(RCC_AHB2ENR_D2SRAM2EN)
  RCC->AHB2ENR |= (RCC_AHB2ENR_D2SRAM1EN | RCC_AHB2ENR_D2SRAM2EN);
#else
  RCC->AHB2ENR |= (RCC_AHB2ENR_AHBSRAM1EN | RCC_AHB2ENR_AHBSRAM2EN);
#endif /* RCC_AHB2ENR_D2SRAM3EN */

  tmpreg = RCC->AHB2ENR;
  (void) tmpreg;
#endif /* DATA_IN_D2_SRAM */

#if defined(DUAL_CORE) && defined(CORE_CM4)
  /* Configure the Vector Table location add offset address for cortex-M4 ------------------*/
#if defined(USER_VECT_TAB_ADDRESS)
  SCB->VTOR = VECT_TAB_BASE_ADDRESS | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal D2 AXI-RAM or in Internal FLASH */
#endif /* USER_VECT_TAB_ADDRESS */

#else
  /*
   * Disable the FMC bank1 (enabled after reset).
   * This, prevents CPU speculation access on this bank which blocks the use of FMC during
   * 24us. During this time the others FMC master (such as LTDC) cannot use it!
   */
  FMC_Bank1_R->BTCR[0] = 0x000030D2;

  /* Configure the Vector Table location -------------------------------------*/
#if defined(USER_VECT_TAB_ADDRESS)
  SCB->VTOR = VECT_TAB_BASE_ADDRESS | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal D1 AXI-RAM or in Internal FLASH */
  __enable_irq();
#endif /* USER_VECT_TAB_ADDRESS */

#endif /*DUAL_CORE && CORE_CM4*/
}

/**
   * @brief  Update SystemCoreClock variable according to Clock Register Values.
  *         The SystemCoreClock variable contains the core clock , it can
  *         be used by the user application to setup the SysTick timer or configure
  *         other parameters.
  *
  * @NOTE   Each time the core clock changes, this function must be called
  *         to update SystemCoreClock variable value. Otherwise, any configuration
  *         based on this variable will be incorrect.
  *
  * @note   - The system frequency computed by this function is not the real
  *           frequency in the chip. It is calculated based on the predefined
  *           constant and the selected clock source:
  *
  *           - If SYSCLK source is CSI, SystemCoreClock will contain the CSI_VALUE(*)
  *           - If SYSCLK source is HSI, SystemCoreClock will contain the HSI_VALUE(**)
  *           - If SYSCLK source is HSE, SystemCoreClock will contain the HSE_VALUE(***)
  *           - If SYSCLK source is PLL, SystemCoreClock will contain the CSI_VALUE(*),
  *             HSI_VALUE(**) or HSE_VALUE(***) multiplied/divided by the PLL factors.
  *
  *         (*) CSI_VALUE is a constant defined in stm32h7xx_hal.h file (default value
  *             4 MHz) but the real value may vary depending on the variations
  *             in voltage and temperature.
  *         (**) HSI_VALUE is a constant defined in stm32h7xx_hal.h file (default value
  *             64 MHz) but the real value may vary depending on the variations
  *             in voltage and temperature.
  *
  *         (***)HSE_VALUE is a constant defined in stm32h7xx_hal.h file (default value
  *              25 MHz), user has to ensure that HSE_VALUE is same as the real
  *              frequency of the crystal used. Otherwise, this function may
  *              have wrong result.
  *
  *         - The result of this function could be not correct when using fractional
  *           value for HSE crystal.
  * @param  None
  * @retval None
  */
void SystemCoreClockUpdate (void)
{
  uint32_t pllp, pllsource, pllm, pllfracen, hsivalue, tmp;
  uint32_t common_system_clock;
  float_t fracn1, pllvco;


  /* Get SYSCLK source -------------------------------------------------------*/

  switch (RCC->CFGR & RCC_CFGR_SWS)
  {
  case RCC_CFGR_SWS_HSI:  /* HSI used as system clock source */
    common_system_clock = (uint32_t) (HSI_VALUE >> ((RCC->CR & RCC_CR_HSIDIV)>> 3));
    break;

  case RCC_CFGR_SWS_CSI:  /* CSI used as system clock  source */
    common_system_clock = CSI_VALUE;
    break;

  case RCC_CFGR_SWS_HSE:  /* HSE used as system clock  source */
    common_system_clock = HSE_VALUE;
    break;

  case RCC_CFGR_SWS_PLL1:  /* PLL1 used as system clock  source */

    /* PLL_VCO = (HSE_VALUE or HSI_VALUE or CSI_VALUE/ PLLM) * PLLN
    SYSCLK = PLL_VCO / PLLR
    */
    pllsource = (RCC->PLLCKSELR & RCC_PLLCKSELR_PLLSRC);
    pllm = ((RCC->PLLCKSELR & RCC_PLLCKSELR_DIVM1)>> 4)  ;
    pllfracen = ((RCC->PLLCFGR & RCC_PLLCFGR_PLL1FRACEN)>>RCC_PLLCFGR_PLL1FRACEN_Pos);
    fracn1 = (float_t)(uint32_t)(pllfracen* ((RCC->PLL1FRACR & RCC_PLL1FRACR_FRACN1)>> 3));

    if (pllm != 0U)
    {
      switch (pllsource)
      {
        case RCC_PLLCKSELR_PLLSRC_HSI:  /* HSI used as PLL clock source */

        hsivalue = (HSI_VALUE >> ((RCC->CR & RCC_CR_HSIDIV)>> 3)) ;
        pllvco = ( (float_t)hsivalue / (float_t)pllm) * ((float_t)(uint32_t)(RCC->PLL1DIVR & RCC_PLL1DIVR_N1) + (fracn1/(float_t)0x2000) +(float_t)1 );

        break;

        case RCC_PLLCKSELR_PLLSRC_CSI:  /* CSI used as PLL clock source */
          pllvco = ((float_t)CSI_VALUE / (float_t)pllm) * ((float_t)(uint32_t)(RCC->PLL1DIVR & RCC_PLL1DIVR_N1) + (fracn1/(float_t)0x2000) +(float_t)1 );
        break;

        case RCC_PLLCKSELR_PLLSRC_HSE:  /* HSE used as PLL clock source */
          pllvco = ((float_t)HSE_VALUE / (float_t)pllm) * ((float_t)(uint32_t)(RCC->PLL1DIVR & RCC_PLL1DIVR_N1) + (fracn1/(float_t)0x2000) +(float_t)1 );
        break;

      default:
          hsivalue = (HSI_VALUE >> ((RCC->CR & RCC_CR_HSIDIV)>> 3)) ;
          pllvco = ((float_t)hsivalue / (float_t)pllm) * ((float_t)(uint32_t)(RCC->PLL1DIVR & RCC_PLL1DIVR_N1) + (fracn1/(float_t)0x2000) +(float_t)1 );
        break;
      }
      pllp = (((RCC->PLL1DIVR & RCC_PLL1DIVR_P1) >>9) + 1U ) ;
      common_system_clock =  (uint32_t)(float_t)(pllvco/(float_t)pllp);
    }
    else
    {
      common_system_clock = 0U;
    }
    break;

  default:
    common_system_clock = (uint32_t) (HSI_VALUE >> ((RCC->CR & RCC_CR_HSIDIV)>> 3));
    break;
  }

  /* Compute SystemClock frequency --------------------------------------------------*/
#if defined (RCC_D1CFGR_D1CPRE)
  tmp = D1CorePrescTable[(RCC->D1CFGR & RCC_D1CFGR_D1CPRE)>> RCC_D1CFGR_D1CPRE_Pos];

  /* common_system_clock frequency : CM7 CPU frequency  */
  common_system_clock >>= tmp;

  /* SystemD2Clock frequency : CM4 CPU, AXI and AHBs Clock frequency  */
  SystemD2Clock = (common_system_clock >> ((D1CorePrescTable[(RCC->D1CFGR & RCC_D1CFGR_HPRE)>> RCC_D1CFGR_HPRE_Pos]) & 0x1FU));

#else
  tmp = D1CorePrescTable[(RCC->CDCFGR1 & RCC_CDCFGR1_CDCPRE)>> RCC_CDCFGR1_CDCPRE_Pos];

  /* common_system_clock frequency : CM7 CPU frequency  */
  common_system_clock >>= tmp;

  /* SystemD2Clock frequency : AXI and AHBs Clock frequency  */
  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 */
}


/**
  * @}
  */

/**
  * @}
  */

/**
  * @}
  */

————————————————

                            版权声明:本文为博主原创文章,遵循 CC 4.0 BY-SA 版权协议,转载请附上原文出处链接和本声明。

原文链接:https://blog.csdn.net/qq_44074966/article/details/136184909

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