text: /**
    ******************************************************************************
    * @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 0x200. */
  #define VECT_TAB_OFFSET         0x00000000U       /*!< Vector Table base offset field.
                                                         This value must be a multiple of 0x200. */
  #else
  #define VECT_TAB_BASE_ADDRESS   FLASH_BANK2_BASE  /*!< Vector Table base address field.
                                                         This value must be a multiple of 0x200. */
  #define VECT_TAB_OFFSET         0x00000000U       /*!< Vector Table base offset field.
                                                         This value must be a multiple of 0x200. */
  #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 0x200. */
  #define VECT_TAB_OFFSET         0x00000000U       /*!< Vector Table base offset field.
                                                         This value must be a multiple of 0x200. */
  #else
  #define VECT_TAB_BASE_ADDRESS   FLASH_BANK1_BASE  /*!< Vector Table base address field.
                                                         This value must be a multiple of 0x200. */
  #define VECT_TAB_OFFSET         0x00000000U       /*!< Vector Table base offset field.
                                                         This value must be a multiple of 0x200. */
  #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
  
  #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*/
  
  }
  
  /**
     * @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 */
  }
  
  
  /**
    * @}
    */
  
  /**
    * @}
    */
  
  /**
    * @}
    */
  