sync/core/system_stm32f4xx.c

/**
 ******************************************************************************
 * @file    system_stm32f4xx.c
 * @author  MCD Application Team
 * @version V1.8.1
 * @date    27-January-2022
 * @brief   CMSIS Cortex-M4 Device Peripheral Access Layer System Source File.
 *          This file contains the system clock configuration for STM32F4xx devices.
 *
 * 1.  This file provides two functions and one global variable to be called from
 *     user application:
 *      - SystemInit(): Setups the system clock (System clock source, PLL Multiplier
 *                      and Divider factors, AHB/APBx prescalers and Flash settings),
 *                      depending on the configuration made in the clock xls tool.
 *                      This function is called at startup just after reset and
 *                      before branch to main program. This call is made inside
 *                      the "startup_stm32f4xx.s" file.
 *
 *      - SystemCoreClock variable: Contains the core clock (HCLK), 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.
 *
 * 2. After each device reset the HSI (16 MHz) is used as system clock source.
 *    Then SystemInit() function is called, in "startup_stm32f4xx.s" file, to
 *    configure the system clock before to branch to main program.
 *
 * 3. If the system clock source selected by user fails to startup, the SystemInit()
 *    function will do nothing and HSI still used as system clock source. User can
 *    add some code to deal with this issue inside the SetSysClock() function.
 *
 * 4. The default value of HSE crystal is set to 25MHz, refer to "HSE_VALUE" define
 *    in "stm32f4xx.h" file. When HSE is used as system clock source, directly or
 *    through PLL, and you are using different crystal you have to adapt the HSE
 *    value to your own configuration.
 *
 * 5. This file configures the system clock as follows:
 *=============================================================================
 *=============================================================================
 *                    Supported STM32F40xxx/41xxx devices
 *-----------------------------------------------------------------------------
 *        System Clock source                    | PLL (HSE)
 *-----------------------------------------------------------------------------
 *        SYSCLK(Hz)                             | 168000000
 *-----------------------------------------------------------------------------
 *        HCLK(Hz)                               | 168000000
 *-----------------------------------------------------------------------------
 *        AHB Prescaler                          | 1
 *-----------------------------------------------------------------------------
 *        APB1 Prescaler                         | 4
 *-----------------------------------------------------------------------------
 *        APB2 Prescaler                         | 2
 *-----------------------------------------------------------------------------
 *        HSE Frequency(Hz)                      | 25000000
 *-----------------------------------------------------------------------------
 *        PLL_M                                  | 25
 *-----------------------------------------------------------------------------
 *        PLL_N                                  | 336
 *-----------------------------------------------------------------------------
 *        PLL_P                                  | 2
 *-----------------------------------------------------------------------------
 *        PLL_Q                                  | 7
 *-----------------------------------------------------------------------------
 *        PLLI2S_N                               | NA
 *-----------------------------------------------------------------------------
 *        PLLI2S_R                               | NA
 *-----------------------------------------------------------------------------
 *        I2S input clock                        | NA
 *-----------------------------------------------------------------------------
 *        VDD(V)                                 | 3.3
 *-----------------------------------------------------------------------------
 *        Main regulator output voltage          | Scale1 mode
 *-----------------------------------------------------------------------------
 *        Flash Latency(WS)                      | 5
 *-----------------------------------------------------------------------------
 *        Prefetch Buffer                        | ON
 *-----------------------------------------------------------------------------
 *        Instruction cache                      | ON
 *-----------------------------------------------------------------------------
 *        Data cache                             | ON
 *-----------------------------------------------------------------------------
 *        Require 48MHz for USB OTG FS,          | Disabled
 *        SDIO and RNG clock                     |
 *-----------------------------------------------------------------------------
 *=============================================================================
 *=============================================================================
 *                    Supported STM32F42xxx/43xxx devices
 *-----------------------------------------------------------------------------
 *        System Clock source                    | PLL (HSE)
 *-----------------------------------------------------------------------------
 *        SYSCLK(Hz)                             | 180000000
 *-----------------------------------------------------------------------------
 *        HCLK(Hz)                               | 180000000
 *-----------------------------------------------------------------------------
 *        AHB Prescaler                          | 1
 *-----------------------------------------------------------------------------
 *        APB1 Prescaler                         | 4
 *-----------------------------------------------------------------------------
 *        APB2 Prescaler                         | 2
 *-----------------------------------------------------------------------------
 *        HSE Frequency(Hz)                      | 25000000
 *-----------------------------------------------------------------------------
 *        PLL_M                                  | 25
 *-----------------------------------------------------------------------------
 *        PLL_N                                  | 360
 *-----------------------------------------------------------------------------
 *        PLL_P                                  | 2
 *-----------------------------------------------------------------------------
 *        PLL_Q                                  | 7
 *-----------------------------------------------------------------------------
 *        PLLI2S_N                               | NA
 *-----------------------------------------------------------------------------
 *        PLLI2S_R                               | NA
 *-----------------------------------------------------------------------------
 *        I2S input clock                        | NA
 *-----------------------------------------------------------------------------
 *        VDD(V)                                 | 3.3
 *-----------------------------------------------------------------------------
 *        Main regulator output voltage          | Scale1 mode
 *-----------------------------------------------------------------------------
 *        Flash Latency(WS)                      | 5
 *-----------------------------------------------------------------------------
 *        Prefetch Buffer                        | ON
 *-----------------------------------------------------------------------------
 *        Instruction cache                      | ON
 *-----------------------------------------------------------------------------
 *        Data cache                             | ON
 *-----------------------------------------------------------------------------
 *        Require 48MHz for USB OTG FS,          | Disabled
 *        SDIO and RNG clock                     |
 *-----------------------------------------------------------------------------
 *=============================================================================
 *=============================================================================
 *                         Supported STM32F401xx devices
 *-----------------------------------------------------------------------------
 *        System Clock source                    | PLL (HSE)
 *-----------------------------------------------------------------------------
 *        SYSCLK(Hz)                             | 84000000
 *-----------------------------------------------------------------------------
 *        HCLK(Hz)                               | 84000000
 *-----------------------------------------------------------------------------
 *        AHB Prescaler                          | 1
 *-----------------------------------------------------------------------------
 *        APB1 Prescaler                         | 2
 *-----------------------------------------------------------------------------
 *        APB2 Prescaler                         | 1
 *-----------------------------------------------------------------------------
 *        HSE Frequency(Hz)                      | 25000000
 *-----------------------------------------------------------------------------
 *        PLL_M                                  | 25
 *-----------------------------------------------------------------------------
 *        PLL_N                                  | 336
 *-----------------------------------------------------------------------------
 *        PLL_P                                  | 4
 *-----------------------------------------------------------------------------
 *        PLL_Q                                  | 7
 *-----------------------------------------------------------------------------
 *        PLLI2S_N                               | NA
 *-----------------------------------------------------------------------------
 *        PLLI2S_R                               | NA
 *-----------------------------------------------------------------------------
 *        I2S input clock                        | NA
 *-----------------------------------------------------------------------------
 *        VDD(V)                                 | 3.3
 *-----------------------------------------------------------------------------
 *        Main regulator output voltage          | Scale1 mode
 *-----------------------------------------------------------------------------
 *        Flash Latency(WS)                      | 2
 *-----------------------------------------------------------------------------
 *        Prefetch Buffer                        | ON
 *-----------------------------------------------------------------------------
 *        Instruction cache                      | ON
 *-----------------------------------------------------------------------------
 *        Data cache                             | ON
 *-----------------------------------------------------------------------------
 *        Require 48MHz for USB OTG FS,          | Disabled
 *        SDIO and RNG clock                     |
 *-----------------------------------------------------------------------------
 *=============================================================================
 *=============================================================================
 *                Supported STM32F411xx/STM32F410xx devices
 *-----------------------------------------------------------------------------
 *        System Clock source                    | PLL (HSI)
 *-----------------------------------------------------------------------------
 *        SYSCLK(Hz)                             | 100000000
 *-----------------------------------------------------------------------------
 *        HCLK(Hz)                               | 100000000
 *-----------------------------------------------------------------------------
 *        AHB Prescaler                          | 1
 *-----------------------------------------------------------------------------
 *        APB1 Prescaler                         | 2
 *-----------------------------------------------------------------------------
 *        APB2 Prescaler                         | 1
 *-----------------------------------------------------------------------------
 *        HSI Frequency(Hz)                      | 16000000
 *-----------------------------------------------------------------------------
 *        PLL_M                                  | 16
 *-----------------------------------------------------------------------------
 *        PLL_N                                  | 400
 *-----------------------------------------------------------------------------
 *        PLL_P                                  | 4
 *-----------------------------------------------------------------------------
 *        PLL_Q                                  | 7
 *-----------------------------------------------------------------------------
 *        PLLI2S_N                               | NA
 *-----------------------------------------------------------------------------
 *        PLLI2S_R                               | NA
 *-----------------------------------------------------------------------------
 *        I2S input clock                        | NA
 *-----------------------------------------------------------------------------
 *        VDD(V)                                 | 3.3
 *-----------------------------------------------------------------------------
 *        Main regulator output voltage          | Scale1 mode
 *-----------------------------------------------------------------------------
 *        Flash Latency(WS)                      | 3
 *-----------------------------------------------------------------------------
 *        Prefetch Buffer                        | ON
 *-----------------------------------------------------------------------------
 *        Instruction cache                      | ON
 *-----------------------------------------------------------------------------
 *        Data cache                             | ON
 *-----------------------------------------------------------------------------
 *        Require 48MHz for USB OTG FS,          | Disabled
 *        SDIO and RNG clock                     |
 *-----------------------------------------------------------------------------
 *=============================================================================
 *=============================================================================
 *                         Supported STM32F446xx devices
 *-----------------------------------------------------------------------------
 *        System Clock source                    | PLL (HSE)
 *-----------------------------------------------------------------------------
 *        SYSCLK(Hz)                             | 180000000
 *-----------------------------------------------------------------------------
 *        HCLK(Hz)                               | 180000000
 *-----------------------------------------------------------------------------
 *        AHB Prescaler                          | 1
 *-----------------------------------------------------------------------------
 *        APB1 Prescaler                         | 4
 *-----------------------------------------------------------------------------
 *        APB2 Prescaler                         | 2
 *-----------------------------------------------------------------------------
 *        HSE Frequency(Hz)                      | 8000000
 *-----------------------------------------------------------------------------
 *        PLL_M                                  | 8
 *-----------------------------------------------------------------------------
 *        PLL_N                                  | 360
 *-----------------------------------------------------------------------------
 *        PLL_P                                  | 2
 *-----------------------------------------------------------------------------
 *        PLL_Q                                  | 7
 *-----------------------------------------------------------------------------
 *        PLL_R                                  | NA
 *-----------------------------------------------------------------------------
 *        PLLI2S_M                               | NA
 *-----------------------------------------------------------------------------
 *        PLLI2S_N                               | NA
 *-----------------------------------------------------------------------------
 *        PLLI2S_P                               | NA
 *-----------------------------------------------------------------------------
 *        PLLI2S_Q                               | NA
 *-----------------------------------------------------------------------------
 *        PLLI2S_R                               | NA
 *-----------------------------------------------------------------------------
 *        I2S input clock                        | NA
 *-----------------------------------------------------------------------------
 *        VDD(V)                                 | 3.3
 *-----------------------------------------------------------------------------
 *        Main regulator output voltage          | Scale1 mode
 *-----------------------------------------------------------------------------
 *        Flash Latency(WS)                      | 5
 *-----------------------------------------------------------------------------
 *        Prefetch Buffer                        | ON
 *-----------------------------------------------------------------------------
 *        Instruction cache                      | ON
 *-----------------------------------------------------------------------------
 *        Data cache                             | ON
 *-----------------------------------------------------------------------------
 *        Require 48MHz for USB OTG FS,          | Disabled
 *        SDIO and RNG clock                     |
 *-----------------------------------------------------------------------------
 *=============================================================================
 ******************************************************************************
 * @attention
 *
 * Copyright (c) 2016 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 stm32f4xx_system
 * @{
 */

/** @addtogroup STM32F4xx_System_Private_Includes
 * @{
 */

#include "stm32f4xx.h"

/**
 * @}
 */

/** @addtogroup STM32F4xx_System_Private_TypesDefinitions
 * @{
 */

/**
 * @}
 */

/** @addtogroup STM32F4xx_System_Private_Defines
 * @{
 */

/************************* Miscellaneous Configuration ************************/
/*!< Uncomment the following line if you need to use external SRAM or SDRAM mounted
     on STM324xG_EVAL/STM324x7I_EVAL/STM324x9I_EVAL boards as data memory  */
#if defined(STM32F40_41xxx) || defined(STM32F427_437xx) || defined(STM32F429_439xx) || defined(STM32F469_479xx) || defined(STM32F413_423xx)
/* #define DATA_IN_ExtSRAM */
#endif /* STM32F40_41xxx || STM32F427_437x || STM32F429_439xx || STM32F469_479xx || STM32F413_423xx */

#if defined(STM32F427_437xx) || defined(STM32F429_439xx) || defined(STM32F446xx) || defined(STM32F469_479xx)
/* #define DATA_IN_ExtSDRAM */
#endif /* STM32F427_437x || STM32F429_439xx || STM32F446xx || STM32F469_479xx */

#if defined(STM32F410xx) || defined(STM32F411xE)
/*!< Uncomment the following line if you need to clock the STM32F410xx/STM32F411xE by HSE Bypass
     through STLINK MCO pin of STM32F103 microcontroller. The frequency cannot be changed
     and is fixed at 8 MHz.
     Hardware configuration needed for Nucleo Board:
     – SB54, SB55 OFF
     – R35 removed
     – SB16, SB50 ON */
/* #define USE_HSE_BYPASS */

#if defined(USE_HSE_BYPASS)
#define HSE_BYPASS_INPUT_FREQUENCY 8000000
#endif /* USE_HSE_BYPASS */
#endif /* STM32F410xx || STM32F411xE */

/*!< Uncomment the following line if you need to relocate your vector Table in
     Internal SRAM. */
/* #define VECT_TAB_SRAM */
#define VECT_TAB_OFFSET 0x80000 /*!< Vector Table base offset field. \
                                  This value must be a multiple of 0x200. */
/******************************************************************************/

/************************* PLL Parameters *************************************/
#if defined(STM32F40_41xxx) || defined(STM32F427_437xx) || defined(STM32F429_439xx) || defined(STM32F401xx) || defined(STM32F469_479xx)
/* PLL_VCO = (HSE_VALUE or HSI_VALUE / PLL_M) * PLL_N */
#define PLL_M 8
#elif defined(STM32F412xG) || defined(STM32F413_423xx) || defined(STM32F446xx)
#define PLL_M 8
#elif defined(STM32F410xx) || defined(STM32F411xE)
#if defined(USE_HSE_BYPASS)
#define PLL_M 8
#else /* !USE_HSE_BYPASS */
#define PLL_M 16
#endif /* USE_HSE_BYPASS */
#else
#endif /* STM32F40_41xxx || STM32F427_437xx || STM32F429_439xx || STM32F401xx || STM32F469_479xx */

/* USB OTG FS, SDIO and RNG Clock =  PLL_VCO / PLLQ */
#define PLL_Q 4

#if defined(STM32F446xx)
/* PLL division factor for I2S, SAI, SYSTEM and SPDIF: Clock =  PLL_VCO / PLLR */
#define PLL_R 7
#elif defined(STM32F412xG) || defined(STM32F413_423xx)
#define PLL_R 2
#else
#endif /* STM32F446xx */

#if defined(STM32F427_437xx) || defined(STM32F429_439xx) || defined(STM32F446xx) || defined(STM32F469_479xx)
#define PLL_N 160
/* SYSCLK = PLL_VCO / PLL_P */
#define PLL_P 2
#endif /* STM32F427_437x || STM32F429_439xx || STM32F446xx || STM32F469_479xx */

#if defined(STM32F40_41xxx)
#define PLL_N 336
/* SYSCLK = PLL_VCO / PLL_P */
#define PLL_P 2
#endif /* STM32F40_41xxx */

#if defined(STM32F401xx)
#define PLL_N 336
/* SYSCLK = PLL_VCO / PLL_P */
#define PLL_P 4
#endif /* STM32F401xx */

#if defined(STM32F410xx) || defined(STM32F411xE) || defined(STM32F412xG) || defined(STM32F413_423xx)
#define PLL_N 400
/* SYSCLK = PLL_VCO / PLL_P */
#define PLL_P 4
#endif /* STM32F410xx || STM32F411xE || STM32F412xG || STM32F413_423xx */

/******************************************************************************/

/**
 * @}
 */

/** @addtogroup STM32F4xx_System_Private_Macros
 * @{
 */

/**
 * @}
 */

/** @addtogroup STM32F4xx_System_Private_Variables
 * @{
 */

#if defined(STM32F40_41xxx)
uint32_t SystemCoreClock = 168000000;
#endif /* STM32F40_41xxx */

#if defined(STM32F427_437xx) || defined(STM32F429_439xx) || defined(STM32F446xx) || defined(STM32F469_479xx)
uint32_t SystemCoreClock = 180000000;
#endif /* STM32F427_437x || STM32F429_439xx || STM32F446xx || STM32F469_479xx */

#if defined(STM32F401xx)
uint32_t SystemCoreClock = 84000000;
#endif /* STM32F401xx */

#if defined(STM32F410xx) || defined(STM32F411xE) || defined(STM32F412xG) || defined(STM32F413_423xx)
uint32_t SystemCoreClock = 100000000;
#endif /* STM32F410xx || STM32F401xE || STM32F412xG || STM32F413_423xx */

__I uint8_t AHBPrescTable[16] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9};

/**
 * @}
 */

/** @addtogroup STM32F4xx_System_Private_FunctionPrototypes
 * @{
 */

static void SetSysClock(void);

#if defined(DATA_IN_ExtSRAM) || defined(DATA_IN_ExtSDRAM)
static void SystemInit_ExtMemCtl(void);
#endif /* DATA_IN_ExtSRAM || DATA_IN_ExtSDRAM */

/**
 * @}
 */

/** @addtogroup STM32F4xx_System_Private_Functions
 * @{
 */

/**
 * @brief  Setup the microcontroller system
 *         Initialize the Embedded Flash Interface, the PLL and update the
 *         SystemFrequency variable.
 * @param  None
 * @retval None
 */
void SystemInit(void)
{
/* 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 ------------*/
  /* Set HSION bit */
  RCC->CR |= (uint32_t)0x00000001;

  /* Reset CFGR register */
  RCC->CFGR = 0x00000000;
  // // MCO1(12.288MHz)
  // RCC->CFGR |= 0x03 << 21; // add by zhoutao(2023-09-19)
  // RCC->CFGR |= 0x06 << 24; // add by zhoutao(2023-09-19)
  // MCO2(12.288MHz)
  RCC->CFGR |= 0x01 << 30; // add by zhoutao(2023-09-19)
  RCC->CFGR |= 0x07 << 27; // add by zhoutao(2023-09-19)

  /* Reset HSEON, CSSON and PLLON bits */
  RCC->CR &= (uint32_t)0xFEF6FFFF;

  /* Reset PLLCFGR register */
  RCC->PLLCFGR = 0x24003010;

  /* Reset HSEBYP bit */
  RCC->CR &= (uint32_t)0xFFFBFFFF;

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

#if defined(DATA_IN_ExtSRAM) || defined(DATA_IN_ExtSDRAM)
  SystemInit_ExtMemCtl();
#endif /* DATA_IN_ExtSRAM || DATA_IN_ExtSDRAM */

  /* Configure the System clock source, PLL Multiplier and Divider factors,
     AHB/APBx prescalers and Flash settings ----------------------------------*/
  SetSysClock();

  /* Configure the Vector Table location add offset address ------------------*/
#ifdef VECT_TAB_SRAM
  SCB->VTOR = SRAM_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal SRAM */
#else
  SCB->VTOR = FLASH_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal FLASH */
#endif
}

/**
 * @brief  Update SystemCoreClock variable according to Clock Register Values.
 *         The SystemCoreClock variable contains the core clock (HCLK), it can
 *         be used by the user application to setup the SysTick timer or configure
 *         other parameters.
 *
 * @note   Each time the core clock (HCLK) 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 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 HSE_VALUE(**)
 *             or HSI_VALUE(*) multiplied/divided by the PLL factors.
 *
 *         (*) HSI_VALUE is a constant defined in stm32f4xx.h file (default value
 *             16 MHz) but the real value may vary depending on the variations
 *             in voltage and temperature.
 *
 *         (**) HSE_VALUE is a constant defined in stm32f4xx.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 tmp = 0, pllvco = 0, pllp = 2, pllsource = 0, pllm = 2;
#if defined(STM32F412xG) || defined(STM32F413_423xx) || defined(STM32F446xx)
  uint32_t pllr = 2;
#endif /* STM32F412xG || STM32F413_423xx || STM32F446xx */
  /* Get SYSCLK source -------------------------------------------------------*/
  tmp = RCC->CFGR & RCC_CFGR_SWS;

  switch (tmp)
  {
  case 0x00: /* HSI used as system clock source */
    SystemCoreClock = HSI_VALUE;
    break;
  case 0x04: /* HSE used as system clock source */
    SystemCoreClock = HSE_VALUE;
    break;
  case 0x08: /* PLL P used as system clock source */
             /* PLL_VCO = (HSE_VALUE or HSI_VALUE / PLL_M) * PLL_N
               SYSCLK = PLL_VCO / PLL_P
               */
    pllsource = (RCC->PLLCFGR & RCC_PLLCFGR_PLLSRC) >> 22;
    pllm = RCC->PLLCFGR & RCC_PLLCFGR_PLLM;

#if defined(STM32F40_41xxx) || defined(STM32F427_437xx) || defined(STM32F429_439xx) || defined(STM32F401xx) || defined(STM32F412xG) || defined(STM32F413_423xx) || defined(STM32F446xx) || defined(STM32F469_479xx)
    if (pllsource != 0)
    {
      /* HSE used as PLL clock source */
      pllvco = (HSE_VALUE / pllm) * ((RCC->PLLCFGR & RCC_PLLCFGR_PLLN) >> 6);
    }
    else
    {
      /* HSI used as PLL clock source */
      pllvco = (HSI_VALUE / pllm) * ((RCC->PLLCFGR & RCC_PLLCFGR_PLLN) >> 6);
    }
#elif defined(STM32F410xx) || defined(STM32F411xE)
#if defined(USE_HSE_BYPASS)
    if (pllsource != 0)
    {
      /* HSE used as PLL clock source */
      pllvco = (HSE_BYPASS_INPUT_FREQUENCY / pllm) * ((RCC->PLLCFGR & RCC_PLLCFGR_PLLN) >> 6);
    }
#else
    if (pllsource == 0)
    {
      /* HSI used as PLL clock source */
      pllvco = (HSI_VALUE / pllm) * ((RCC->PLLCFGR & RCC_PLLCFGR_PLLN) >> 6);
    }
#endif /* USE_HSE_BYPASS */
#endif /* STM32F40_41xxx || STM32F427_437xx || STM32F429_439xx || STM32F401xx || STM32F412xG || STM32F413_423xx ||  STM32F446xx || STM32F469_479xx */
    pllp = (((RCC->PLLCFGR & RCC_PLLCFGR_PLLP) >> 16) + 1) * 2;
    SystemCoreClock = pllvco / pllp;
    break;
#if defined(STM32F412xG) || defined(STM32F413_423xx) || defined(STM32F446xx)
  case 0x0C: /* PLL R used as system clock source */
             /* PLL_VCO = (HSE_VALUE or HSI_VALUE / PLL_M) * PLL_N
               SYSCLK = PLL_VCO / PLL_R
               */
    pllsource = (RCC->PLLCFGR & RCC_PLLCFGR_PLLSRC) >> 22;
    pllm = RCC->PLLCFGR & RCC_PLLCFGR_PLLM;
    if (pllsource != 0)
    {
      /* HSE used as PLL clock source */
      pllvco = (HSE_VALUE / pllm) * ((RCC->PLLCFGR & RCC_PLLCFGR_PLLN) >> 6);
    }
    else
    {
      /* HSI used as PLL clock source */
      pllvco = (HSI_VALUE / pllm) * ((RCC->PLLCFGR & RCC_PLLCFGR_PLLN) >> 6);
    }

    pllr = (((RCC->PLLCFGR & RCC_PLLCFGR_PLLR) >> 28) + 1) * 2;
    SystemCoreClock = pllvco / pllr;
    break;
#endif /* STM32F412xG || STM32F413_423xx || STM32F446xx */
  default:
    SystemCoreClock = HSI_VALUE;
    break;
  }
  /* Compute HCLK frequency --------------------------------------------------*/
  /* Get HCLK prescaler */
  tmp = AHBPrescTable[((RCC->CFGR & RCC_CFGR_HPRE) >> 4)];
  /* HCLK frequency */
  SystemCoreClock >>= tmp;
}

/**
 * @brief  Configures the System clock source, PLL Multiplier and Divider factors,
 *         AHB/APBx prescalers and Flash settings
 * @Note   This function should be called only once the RCC clock configuration
 *         is reset to the default reset state (done in SystemInit() function).
 * @param  None
 * @retval None
 */
static void SetSysClock(void)
{
#if defined(STM32F40_41xxx) || defined(STM32F427_437xx) || defined(STM32F429_439xx) || defined(STM32F401xx) || defined(STM32F412xG) || defined(STM32F413_423xx) || defined(STM32F446xx) || defined(STM32F469_479xx)
  /******************************************************************************/
  /*            PLL (clocked by HSE) used as System clock source                */
  /******************************************************************************/
  __IO uint32_t StartUpCounter = 0, HSEStatus = 0;

  /* 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)
  {
    /* Select regulator voltage output Scale 1 mode */
    RCC->APB1ENR |= RCC_APB1ENR_PWREN;
    PWR->CR |= PWR_CR_VOS_1; // PWR_CR_VOS;//ģʽ3

    /* HCLK = SYSCLK / 1*/
    RCC->CFGR |= RCC_CFGR_HPRE_DIV1;

#if defined(STM32F40_41xxx) || defined(STM32F427_437xx) || defined(STM32F429_439xx) || defined(STM32F412xG) || defined(STM32F446xx) || defined(STM32F469_479xx)
    /* PCLK2 = HCLK / 2*/
    RCC->CFGR |= RCC_CFGR_PPRE2_DIV2;

    /* PCLK1 = HCLK / 4*/
    RCC->CFGR |= RCC_CFGR_PPRE1_DIV4;
#endif /* STM32F40_41xxx || STM32F427_437x || STM32F429_439xx  || STM32F412xG || STM32F446xx || STM32F469_479xx */

#if defined(STM32F401xx) || defined(STM32F413_423xx)
    /* PCLK2 = HCLK / 1*/
    RCC->CFGR |= RCC_CFGR_PPRE2_DIV1;

    /* PCLK1 = HCLK / 2*/
    RCC->CFGR |= RCC_CFGR_PPRE1_DIV2;
#endif /* STM32F401xx || STM32F413_423xx */

#if defined(STM32F40_41xxx) || defined(STM32F427_437xx) || defined(STM32F429_439xx) || defined(STM32F401xx) || defined(STM32F469_479xx)
    /* Configure the main PLL */
    RCC->PLLCFGR = PLL_M | (PLL_N << 6) | (((PLL_P >> 1) - 1) << 16) |
                   (RCC_PLLCFGR_PLLSRC_HSE) | (PLL_Q << 24);
#endif /* STM32F40_41xxx || STM32F401xx || STM32F427_437x || STM32F429_439xx || STM32F469_479xx */

#if defined(STM32F412xG) || defined(STM32F413_423xx) || defined(STM32F446xx)
    /* Configure the main PLL */
    RCC->PLLCFGR = PLL_M | (PLL_N << 6) | (((PLL_P >> 1) - 1) << 16) |
                   (RCC_PLLCFGR_PLLSRC_HSE) | (PLL_Q << 24) | (PLL_R << 28);
#endif /* STM32F412xG || STM32F413_423xx || STM32F446xx */
    /* Enable the main PLL */
    RCC->CR |= RCC_CR_PLLON;

    /* Wait till the main PLL is ready */
    while ((RCC->CR & RCC_CR_PLLRDY) == 0)
    {
    }

#if defined(STM32F427_437xx) || defined(STM32F429_439xx) || defined(STM32F446xx) || defined(STM32F469_479xx)
    /* Enable the Over-drive to extend the clock frequency to 180 Mhz */
    PWR->CR |= PWR_CR_ODEN;
    while ((PWR->CSR & PWR_CSR_ODRDY) == 0)
    {
    }
    PWR->CR |= PWR_CR_ODSWEN;
    while ((PWR->CSR & PWR_CSR_ODSWRDY) == 0)
    {
    }
    /* Configure Flash prefetch, Instruction cache, Data cache and wait state */
    FLASH->ACR = FLASH_ACR_PRFTEN | FLASH_ACR_ICEN | FLASH_ACR_DCEN | FLASH_ACR_LATENCY_5WS;
#endif /* STM32F427_437x || STM32F429_439xx || STM32F446xx || STM32F469_479xx */

#if defined(STM32F40_41xxx) || defined(STM32F412xG)
    /* Configure Flash prefetch, Instruction cache, Data cache and wait state */
    FLASH->ACR = FLASH_ACR_PRFTEN | FLASH_ACR_ICEN | FLASH_ACR_DCEN | FLASH_ACR_LATENCY_5WS;
#endif /* STM32F40_41xxx  || STM32F412xG */

#if defined(STM32F413_423xx)
    /* Configure Flash prefetch, Instruction cache, Data cache and wait state */
    FLASH->ACR = FLASH_ACR_PRFTEN | FLASH_ACR_ICEN | FLASH_ACR_DCEN | FLASH_ACR_LATENCY_3WS;
#endif /* STM32F413_423xx */

#if defined(STM32F401xx)
    /* Configure Flash prefetch, Instruction cache, Data cache and wait state */
    FLASH->ACR = FLASH_ACR_PRFTEN | FLASH_ACR_ICEN | FLASH_ACR_DCEN | FLASH_ACR_LATENCY_2WS;
#endif /* STM32F401xx */

    /* Select the main PLL as system clock source */
    RCC->CFGR &= (uint32_t)((uint32_t) ~(RCC_CFGR_SW));
    RCC->CFGR |= RCC_CFGR_SW_PLL;

    /* Wait till the main PLL is used as system clock source */
    while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS) != RCC_CFGR_SWS_PLL)
      ;
    {
    }
  }
  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 */
  }
#elif defined(STM32F410xx) || defined(STM32F411xE)
#if defined(USE_HSE_BYPASS)
  /******************************************************************************/
  /*            PLL (clocked by HSE) used as System clock source                */
  /******************************************************************************/
  __IO uint32_t StartUpCounter = 0, HSEStatus = 0;

  /* Enable HSE and HSE BYPASS */
  RCC->CR |= ((uint32_t)RCC_CR_HSEON | RCC_CR_HSEBYP);

  /* 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)
  {
    /* Select regulator voltage output Scale 1 mode */
    RCC->APB1ENR |= RCC_APB1ENR_PWREN;
    PWR->CR |= PWR_CR_VOS;

    /* HCLK = SYSCLK / 1*/
    RCC->CFGR |= RCC_CFGR_HPRE_DIV1;

    /* PCLK2 = HCLK / 2*/
    RCC->CFGR |= RCC_CFGR_PPRE2_DIV1;

    /* PCLK1 = HCLK / 4*/
    RCC->CFGR |= RCC_CFGR_PPRE1_DIV2;

    /* Configure the main PLL */
    RCC->PLLCFGR = PLL_M | (PLL_N << 6) | (((PLL_P >> 1) - 1) << 16) |
                   (RCC_PLLCFGR_PLLSRC_HSE) | (PLL_Q << 24);

    /* Enable the main PLL */
    RCC->CR |= RCC_CR_PLLON;

    /* Wait till the main PLL is ready */
    while ((RCC->CR & RCC_CR_PLLRDY) == 0)
    {
    }

    /* Configure Flash prefetch, Instruction cache, Data cache and wait state */
    FLASH->ACR = FLASH_ACR_PRFTEN | FLASH_ACR_ICEN | FLASH_ACR_DCEN | FLASH_ACR_LATENCY_3WS;

    /* Select the main PLL as system clock source */
    RCC->CFGR &= (uint32_t)((uint32_t) ~(RCC_CFGR_SW));
    RCC->CFGR |= RCC_CFGR_SW_PLL;

    /* Wait till the main PLL is used as system clock source */
    while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS) != RCC_CFGR_SWS_PLL)
      ;
    {
    }
  }
  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 */
  }
#else  /* HSI will be used as PLL clock source */
  /* Select regulator voltage output Scale 1 mode */
  RCC->APB1ENR |= RCC_APB1ENR_PWREN;
  PWR->CR |= PWR_CR_VOS;

  /* HCLK = SYSCLK / 1*/
  RCC->CFGR |= RCC_CFGR_HPRE_DIV1;

  /* PCLK2 = HCLK / 2*/
  RCC->CFGR |= RCC_CFGR_PPRE2_DIV1;

  /* PCLK1 = HCLK / 4*/
  RCC->CFGR |= RCC_CFGR_PPRE1_DIV2;

  /* Configure the main PLL */
  RCC->PLLCFGR = PLL_M | (PLL_N << 6) | (((PLL_P >> 1) - 1) << 16) | (PLL_Q << 24);

  /* Enable the main PLL */
  RCC->CR |= RCC_CR_PLLON;

  /* Wait till the main PLL is ready */
  while ((RCC->CR & RCC_CR_PLLRDY) == 0)
  {
  }

  /* Configure Flash prefetch, Instruction cache, Data cache and wait state */
  FLASH->ACR = FLASH_ACR_PRFTEN | FLASH_ACR_ICEN | FLASH_ACR_DCEN | FLASH_ACR_LATENCY_3WS;

  /* Select the main PLL as system clock source */
  RCC->CFGR &= (uint32_t)((uint32_t) ~(RCC_CFGR_SW));
  RCC->CFGR |= RCC_CFGR_SW_PLL;

  /* Wait till the main PLL is used as system clock source */
  while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS) != RCC_CFGR_SWS_PLL)
    ;
  {
  }
#endif /* USE_HSE_BYPASS */
#endif /* STM32F40_41xxx || STM32F427_437xx || STM32F429_439xx || STM32F401xx || STM32F469_479xx */
}
#if defined(DATA_IN_ExtSRAM) && defined(DATA_IN_ExtSDRAM)
#if defined(STM32F427xx) || defined(STM32F437xx) || defined(STM32F429xx) || defined(STM32F439xx) || \
    defined(STM32F469xx) || defined(STM32F479xx)
/**
 * @brief  Setup the external memory controller.
 *         Called in startup_stm32f4xx.s before jump to main.
 *         This function configures the external memories (SRAM/SDRAM)
 *         This SRAM/SDRAM will be used as program data memory (including heap and stack).
 * @param  None
 * @retval None
 */
void SystemInit_ExtMemCtl(void)
{
  __IO uint32_t tmp = 0x00;

  register uint32_t tmpreg = 0, timeout = 0xFFFF;
  register uint32_t index;

  /* Enable GPIOC, GPIOD, GPIOE, GPIOF, GPIOG, GPIOH and GPIOI interface clock */
  RCC->AHB1ENR |= 0x000001F8;

  /* Delay after an RCC peripheral clock enabling */
  tmp = READ_BIT(RCC->AHB1ENR, RCC_AHB1ENR_GPIOCEN);

  /* Connect PDx pins to FMC Alternate function */
  GPIOD->AFR[0] = 0x00CCC0CC;
  GPIOD->AFR[1] = 0xCCCCCCCC;
  /* Configure PDx pins in Alternate function mode */
  GPIOD->MODER = 0xAAAA0A8A;
  /* Configure PDx pins speed to 100 MHz */
  GPIOD->OSPEEDR = 0xFFFF0FCF;
  /* Configure PDx pins Output type to push-pull */
  GPIOD->OTYPER = 0x00000000;
  /* No pull-up, pull-down for PDx pins */
  GPIOD->PUPDR = 0x00000000;

  /* Connect PEx pins to FMC Alternate function */
  GPIOE->AFR[0] = 0xC00CC0CC;
  GPIOE->AFR[1] = 0xCCCCCCCC;
  /* Configure PEx pins in Alternate function mode */
  GPIOE->MODER = 0xAAAA828A;
  /* Configure PEx pins speed to 100 MHz */
  GPIOE->OSPEEDR = 0xFFFFC3CF;
  /* Configure PEx pins Output type to push-pull */
  GPIOE->OTYPER = 0x00000000;
  /* No pull-up, pull-down for PEx pins */
  GPIOE->PUPDR = 0x00000000;

  /* Connect PFx pins to FMC Alternate function */
  GPIOF->AFR[0] = 0xCCCCCCCC;
  GPIOF->AFR[1] = 0xCCCCCCCC;
  /* Configure PFx pins in Alternate function mode */
  GPIOF->MODER = 0xAA800AAA;
  /* Configure PFx pins speed to 50 MHz */
  GPIOF->OSPEEDR = 0xAA800AAA;
  /* Configure PFx pins Output type to push-pull */
  GPIOF->OTYPER = 0x00000000;
  /* No pull-up, pull-down for PFx pins */
  GPIOF->PUPDR = 0x00000000;

  /* Connect PGx pins to FMC Alternate function */
  GPIOG->AFR[0] = 0xCCCCCCCC;
  GPIOG->AFR[1] = 0xCCCCCCCC;
  /* Configure PGx pins in Alternate function mode */
  GPIOG->MODER = 0xAAAAAAAA;
  /* Configure PGx pins speed to 50 MHz */
  GPIOG->OSPEEDR = 0xAAAAAAAA;
  /* Configure PGx pins Output type to push-pull */
  GPIOG->OTYPER = 0x00000000;
  /* No pull-up, pull-down for PGx pins */
  GPIOG->PUPDR = 0x00000000;

  /* Connect PHx pins to FMC Alternate function */
  GPIOH->AFR[0] = 0x00C0CC00;
  GPIOH->AFR[1] = 0xCCCCCCCC;
  /* Configure PHx pins in Alternate function mode */
  GPIOH->MODER = 0xAAAA08A0;
  /* Configure PHx pins speed to 50 MHz */
  GPIOH->OSPEEDR = 0xAAAA08A0;
  /* Configure PHx pins Output type to push-pull */
  GPIOH->OTYPER = 0x00000000;
  /* No pull-up, pull-down for PHx pins */
  GPIOH->PUPDR = 0x00000000;

  /* Connect PIx pins to FMC Alternate function */
  GPIOI->AFR[0] = 0xCCCCCCCC;
  GPIOI->AFR[1] = 0x00000CC0;
  /* Configure PIx pins in Alternate function mode */
  GPIOI->MODER = 0x0028AAAA;
  /* Configure PIx pins speed to 50 MHz */
  GPIOI->OSPEEDR = 0x0028AAAA;
  /* Configure PIx pins Output type to push-pull */
  GPIOI->OTYPER = 0x00000000;
  /* No pull-up, pull-down for PIx pins */
  GPIOI->PUPDR = 0x00000000;

  /*-- FMC Configuration -------------------------------------------------------*/
  /* Enable the FMC interface clock */
  RCC->AHB3ENR |= 0x00000001;
  /* Delay after an RCC peripheral clock enabling */
  tmp = READ_BIT(RCC->AHB3ENR, RCC_AHB3ENR_FMCEN);

  FMC_Bank5_6->SDCR[0] = 0x000019E4;
  FMC_Bank5_6->SDTR[0] = 0x01115351;

  /* SDRAM initialization sequence */
  /* Clock enable command */
  FMC_Bank5_6->SDCMR = 0x00000011;
  tmpreg = FMC_Bank5_6->SDSR & 0x00000020;
  while ((tmpreg != 0) && (timeout-- > 0))
  {
    tmpreg = FMC_Bank5_6->SDSR & 0x00000020;
  }

  /* Delay */
  for (index = 0; index < 1000; index++)
    ;

  /* PALL command */
  FMC_Bank5_6->SDCMR = 0x00000012;
  timeout = 0xFFFF;
  while ((tmpreg != 0) && (timeout-- > 0))
  {
    tmpreg = FMC_Bank5_6->SDSR & 0x00000020;
  }

  /* Auto refresh command */
  FMC_Bank5_6->SDCMR = 0x00000073;
  timeout = 0xFFFF;
  while ((tmpreg != 0) && (timeout-- > 0))
  {
    tmpreg = FMC_Bank5_6->SDSR & 0x00000020;
  }

  /* MRD register program */
  FMC_Bank5_6->SDCMR = 0x00046014;
  timeout = 0xFFFF;
  while ((tmpreg != 0) && (timeout-- > 0))
  {
    tmpreg = FMC_Bank5_6->SDSR & 0x00000020;
  }

  /* Set refresh count */
  tmpreg = FMC_Bank5_6->SDRTR;
  FMC_Bank5_6->SDRTR = (tmpreg | (0x0000027C << 1));

  /* Disable write protection */
  tmpreg = FMC_Bank5_6->SDCR[0];
  FMC_Bank5_6->SDCR[0] = (tmpreg & 0xFFFFFDFF);

#if defined(STM32F427xx) || defined(STM32F437xx) || defined(STM32F429xx) || defined(STM32F439xx)
  /* Configure and enable Bank1_SRAM2 */
  FMC_Bank1->BTCR[2] = 0x00001011;
  FMC_Bank1->BTCR[3] = 0x00000201;
  FMC_Bank1E->BWTR[2] = 0x0fffffff;
#endif /* STM32F427xx || STM32F437xx || STM32F429xx || STM32F439xx */
#if defined(STM32F469xx) || defined(STM32F479xx)
  /* Configure and enable Bank1_SRAM2 */
  FMC_Bank1->BTCR[2] = 0x00001091;
  FMC_Bank1->BTCR[3] = 0x00110212;
  FMC_Bank1E->BWTR[2] = 0x0fffffff;
#endif /* STM32F469xx || STM32F479xx */

  (void)(tmp);
}
#endif /* STM32F427xx || STM32F437xx || STM32F429xx || STM32F439xx || STM32F469xx || STM32F479xx */
#elif defined(DATA_IN_ExtSRAM)
/**
 * @brief  Setup the external memory controller. Called in startup_stm32f4xx.s
 *          before jump to __main
 * @param  None
 * @retval None
 */
/**
 * @brief  Setup the external memory controller.
 *         Called in startup_stm32f4xx.s before jump to main.
 *         This function configures the external SRAM mounted on STM324xG_EVAL/STM324x7I boards
 *         This SRAM will be used as program data memory (including heap and stack).
 * @param  None
 * @retval None
 */
void SystemInit_ExtMemCtl(void)
{
  /*-- GPIOs Configuration -----------------------------------------------------*/
  /*
   +-------------------+--------------------+------------------+--------------+
   +                       SRAM pins assignment                               +
   +-------------------+--------------------+------------------+--------------+
   | PD0  <-> FMC_D2  | PE0  <-> FMC_NBL0 | PF0  <-> FMC_A0 | PG0 <-> FMC_A10 |
   | PD1  <-> FMC_D3  | PE1  <-> FMC_NBL1 | PF1  <-> FMC_A1 | PG1 <-> FMC_A11 |
   | PD4  <-> FMC_NOE | PE3  <-> FMC_A19  | PF2  <-> FMC_A2 | PG2 <-> FMC_A12 |
   | PD5  <-> FMC_NWE | PE4  <-> FMC_A20  | PF3  <-> FMC_A3 | PG3 <-> FMC_A13 |
   | PD8  <-> FMC_D13 | PE7  <-> FMC_D4   | PF4  <-> FMC_A4 | PG4 <-> FMC_A14 |
   | PD9  <-> FMC_D14 | PE8  <-> FMC_D5   | PF5  <-> FMC_A5 | PG5 <-> FMC_A15 |
   | PD10 <-> FMC_D15 | PE9  <-> FMC_D6   | PF12 <-> FMC_A6 | PG9 <-> FMC_NE2 |
   | PD11 <-> FMC_A16 | PE10 <-> FMC_D7   | PF13 <-> FMC_A7 |-----------------+
   | PD12 <-> FMC_A17 | PE11 <-> FMC_D8   | PF14 <-> FMC_A8 |
   | PD13 <-> FMC_A18 | PE12 <-> FMC_D9   | PF15 <-> FMC_A9 |
   | PD14 <-> FMC_D0  | PE13 <-> FMC_D10  |-----------------+
   | PD15 <-> FMC_D1  | PE14 <-> FMC_D11  |
   |                  | PE15 <-> FMC_D12  |
   +------------------+------------------+
  */
  /* Enable GPIOD, GPIOE, GPIOF and GPIOG interface clock */
  RCC->AHB1ENR |= 0x00000078;

  /* Connect PDx pins to FMC Alternate function */
  GPIOD->AFR[0] = 0x00cc00cc;
  GPIOD->AFR[1] = 0xcccccccc;
  /* Configure PDx pins in Alternate function mode */
  GPIOD->MODER = 0xaaaa0a0a;
  /* Configure PDx pins speed to 100 MHz */
  GPIOD->OSPEEDR = 0xffff0f0f;
  /* Configure PDx pins Output type to push-pull */
  GPIOD->OTYPER = 0x00000000;
  /* No pull-up, pull-down for PDx pins */
  GPIOD->PUPDR = 0x00000000;

  /* Connect PEx pins to FMC Alternate function */
  GPIOE->AFR[0] = 0xcccccccc;
  GPIOE->AFR[1] = 0xcccccccc;
  /* Configure PEx pins in Alternate function mode */
  GPIOE->MODER = 0xaaaaaaaa;
  /* Configure PEx pins speed to 100 MHz */
  GPIOE->OSPEEDR = 0xffffffff;
  /* Configure PEx pins Output type to push-pull */
  GPIOE->OTYPER = 0x00000000;
  /* No pull-up, pull-down for PEx pins */
  GPIOE->PUPDR = 0x00000000;

  /* Connect PFx pins to FMC Alternate function */
  GPIOF->AFR[0] = 0x00cccccc;
  GPIOF->AFR[1] = 0xcccc0000;
  /* Configure PFx pins in Alternate function mode */
  GPIOF->MODER = 0xaa000aaa;
  /* Configure PFx pins speed to 100 MHz */
  GPIOF->OSPEEDR = 0xff000fff;
  /* Configure PFx pins Output type to push-pull */
  GPIOF->OTYPER = 0x00000000;
  /* No pull-up, pull-down for PFx pins */
  GPIOF->PUPDR = 0x00000000;

  /* Connect PGx pins to FMC Alternate function */
  GPIOG->AFR[0] = 0x00cccccc;
  GPIOG->AFR[1] = 0x000000c0;
  /* Configure PGx pins in Alternate function mode */
  GPIOG->MODER = 0x00080aaa;
  /* Configure PGx pins speed to 100 MHz */
  GPIOG->OSPEEDR = 0x000c0fff;
  /* Configure PGx pins Output type to push-pull */
  GPIOG->OTYPER = 0x00000000;
  /* No pull-up, pull-down for PGx pins */
  GPIOG->PUPDR = 0x00000000;

  /*-- FMC Configuration ------------------------------------------------------*/
  /* Enable the FMC/FSMC interface clock */
  RCC->AHB3ENR |= 0x00000001;

#if defined(STM32F427_437xx) || defined(STM32F429_439xx) || defined(STM32F446xx) || defined(STM32F469_479xx)
  /* Configure and enable Bank1_SRAM2 */
  FMC_Bank1->BTCR[2] = 0x00001011;
  FMC_Bank1->BTCR[3] = 0x00000201;
  FMC_Bank1E->BWTR[2] = 0x0fffffff;
#endif /* STM32F427_437xx || STM32F429_439xx || STM32F446xx || STM32F469_479xx */

#if defined(STM32F40_41xxx)
  /* Configure and enable Bank1_SRAM2 */
  FSMC_Bank1->BTCR[2] = 0x00001011;
  FSMC_Bank1->BTCR[3] = 0x00000201;
  FSMC_Bank1E->BWTR[2] = 0x0fffffff;
#endif /* STM32F40_41xxx */

  /*
    Bank1_SRAM2 is configured as follow:
    In case of FSMC configuration
    NORSRAMTimingStructure.FSMC_AddressSetupTime = 1;
    NORSRAMTimingStructure.FSMC_AddressHoldTime = 0;
    NORSRAMTimingStructure.FSMC_DataSetupTime = 2;
    NORSRAMTimingStructure.FSMC_BusTurnAroundDuration = 0;
    NORSRAMTimingStructure.FSMC_CLKDivision = 0;
    NORSRAMTimingStructure.FSMC_DataLatency = 0;
    NORSRAMTimingStructure.FSMC_AccessMode = FMC_AccessMode_A;

    FSMC_NORSRAMInitStructure.FSMC_Bank = FSMC_Bank1_NORSRAM2;
    FSMC_NORSRAMInitStructure.FSMC_DataAddressMux = FSMC_DataAddressMux_Disable;
    FSMC_NORSRAMInitStructure.FSMC_MemoryType = FSMC_MemoryType_SRAM;
    FSMC_NORSRAMInitStructure.FSMC_MemoryDataWidth = FSMC_MemoryDataWidth_16b;
    FSMC_NORSRAMInitStructure.FSMC_BurstAccessMode = FSMC_BurstAccessMode_Disable;
    FSMC_NORSRAMInitStructure.FSMC_AsynchronousWait = FSMC_AsynchronousWait_Disable;
    FSMC_NORSRAMInitStructure.FSMC_WaitSignalPolarity = FSMC_WaitSignalPolarity_Low;
    FSMC_NORSRAMInitStructure.FSMC_WrapMode = FSMC_WrapMode_Disable;
    FSMC_NORSRAMInitStructure.FSMC_WaitSignalActive = FSMC_WaitSignalActive_BeforeWaitState;
    FSMC_NORSRAMInitStructure.FSMC_WriteOperation = FSMC_WriteOperation_Enable;
    FSMC_NORSRAMInitStructure.FSMC_WaitSignal = FSMC_WaitSignal_Disable;
    FSMC_NORSRAMInitStructure.FSMC_ExtendedMode = FSMC_ExtendedMode_Disable;
    FSMC_NORSRAMInitStructure.FSMC_WriteBurst = FSMC_WriteBurst_Disable;
    FSMC_NORSRAMInitStructure.FSMC_ReadWriteTimingStruct = &NORSRAMTimingStructure;
    FSMC_NORSRAMInitStructure.FSMC_WriteTimingStruct = &NORSRAMTimingStructure;

    In case of FMC configuration
    NORSRAMTimingStructure.FMC_AddressSetupTime = 1;
    NORSRAMTimingStructure.FMC_AddressHoldTime = 0;
    NORSRAMTimingStructure.FMC_DataSetupTime = 2;
    NORSRAMTimingStructure.FMC_BusTurnAroundDuration = 0;
    NORSRAMTimingStructure.FMC_CLKDivision = 0;
    NORSRAMTimingStructure.FMC_DataLatency = 0;
    NORSRAMTimingStructure.FMC_AccessMode = FMC_AccessMode_A;

    FMC_NORSRAMInitStructure.FMC_Bank = FMC_Bank1_NORSRAM2;
    FMC_NORSRAMInitStructure.FMC_DataAddressMux = FMC_DataAddressMux_Disable;
    FMC_NORSRAMInitStructure.FMC_MemoryType = FMC_MemoryType_SRAM;
    FMC_NORSRAMInitStructure.FMC_MemoryDataWidth = FMC_MemoryDataWidth_16b;
    FMC_NORSRAMInitStructure.FMC_BurstAccessMode = FMC_BurstAccessMode_Disable;
    FMC_NORSRAMInitStructure.FMC_AsynchronousWait = FMC_AsynchronousWait_Disable;
    FMC_NORSRAMInitStructure.FMC_WaitSignalPolarity = FMC_WaitSignalPolarity_Low;
    FMC_NORSRAMInitStructure.FMC_WrapMode = FMC_WrapMode_Disable;
    FMC_NORSRAMInitStructure.FMC_WaitSignalActive = FMC_WaitSignalActive_BeforeWaitState;
    FMC_NORSRAMInitStructure.FMC_WriteOperation = FMC_WriteOperation_Enable;
    FMC_NORSRAMInitStructure.FMC_WaitSignal = FMC_WaitSignal_Disable;
    FMC_NORSRAMInitStructure.FMC_ExtendedMode = FMC_ExtendedMode_Disable;
    FMC_NORSRAMInitStructure.FMC_WriteBurst = FMC_WriteBurst_Disable;
    FMC_NORSRAMInitStructure.FMC_ContinousClock = FMC_CClock_SyncOnly;
    FMC_NORSRAMInitStructure.FMC_ReadWriteTimingStruct = &NORSRAMTimingStructure;
    FMC_NORSRAMInitStructure.FMC_WriteTimingStruct = &NORSRAMTimingStructure;
  */
}
#elif defined(DATA_IN_ExtSDRAM)
/**
 * @brief  Setup the external memory controller.
 *         Called in startup_stm32f4xx.s before jump to main.
 *         This function configures the external SDRAM mounted on STM324x9I_EVAL board
 *         This SDRAM will be used as program data memory (including heap and stack).
 * @param  None
 * @retval None
 */
void SystemInit_ExtMemCtl(void)
{
  register uint32_t tmpreg = 0, timeout = 0xFFFF;
  register uint32_t index;

  /* Enable GPIOC, GPIOD, GPIOE, GPIOF, GPIOG, GPIOH and GPIOI interface
      clock */
  RCC->AHB1ENR |= 0x000001FC;

  /* Connect PCx pins to FMC Alternate function */
  GPIOC->AFR[0] = 0x0000000c;
  GPIOC->AFR[1] = 0x00007700;
  /* Configure PCx pins in Alternate function mode */
  GPIOC->MODER = 0x00a00002;
  /* Configure PCx pins speed to 50 MHz */
  GPIOC->OSPEEDR = 0x00a00002;
  /* Configure PCx pins Output type to push-pull */
  GPIOC->OTYPER = 0x00000000;
  /* No pull-up, pull-down for PCx pins */
  GPIOC->PUPDR = 0x00500000;

  /* Connect PDx pins to FMC Alternate function */
  GPIOD->AFR[0] = 0x000000CC;
  GPIOD->AFR[1] = 0xCC000CCC;
  /* Configure PDx pins in Alternate function mode */
  GPIOD->MODER = 0xA02A000A;
  /* Configure PDx pins speed to 50 MHz */
  GPIOD->OSPEEDR = 0xA02A000A;
  /* Configure PDx pins Output type to push-pull */
  GPIOD->OTYPER = 0x00000000;
  /* No pull-up, pull-down for PDx pins */
  GPIOD->PUPDR = 0x00000000;

  /* Connect PEx pins to FMC Alternate function */
  GPIOE->AFR[0] = 0xC00000CC;
  GPIOE->AFR[1] = 0xCCCCCCCC;
  /* Configure PEx pins in Alternate function mode */
  GPIOE->MODER = 0xAAAA800A;
  /* Configure PEx pins speed to 50 MHz */
  GPIOE->OSPEEDR = 0xAAAA800A;
  /* Configure PEx pins Output type to push-pull */
  GPIOE->OTYPER = 0x00000000;
  /* No pull-up, pull-down for PEx pins */
  GPIOE->PUPDR = 0x00000000;

  /* Connect PFx pins to FMC Alternate function */
  GPIOF->AFR[0] = 0xcccccccc;
  GPIOF->AFR[1] = 0xcccccccc;
  /* Configure PFx pins in Alternate function mode */
  GPIOF->MODER = 0xAA800AAA;
  /* Configure PFx pins speed to 50 MHz */
  GPIOF->OSPEEDR = 0xAA800AAA;
  /* Configure PFx pins Output type to push-pull */
  GPIOF->OTYPER = 0x00000000;
  /* No pull-up, pull-down for PFx pins */
  GPIOF->PUPDR = 0x00000000;

  /* Connect PGx pins to FMC Alternate function */
  GPIOG->AFR[0] = 0xcccccccc;
  GPIOG->AFR[1] = 0xcccccccc;
  /* Configure PGx pins in Alternate function mode */
  GPIOG->MODER = 0xaaaaaaaa;
  /* Configure PGx pins speed to 50 MHz */
  GPIOG->OSPEEDR = 0xaaaaaaaa;
  /* Configure PGx pins Output type to push-pull */
  GPIOG->OTYPER = 0x00000000;
  /* No pull-up, pull-down for PGx pins */
  GPIOG->PUPDR = 0x00000000;

  /* Connect PHx pins to FMC Alternate function */
  GPIOH->AFR[0] = 0x00C0CC00;
  GPIOH->AFR[1] = 0xCCCCCCCC;
  /* Configure PHx pins in Alternate function mode */
  GPIOH->MODER = 0xAAAA08A0;
  /* Configure PHx pins speed to 50 MHz */
  GPIOH->OSPEEDR = 0xAAAA08A0;
  /* Configure PHx pins Output type to push-pull */
  GPIOH->OTYPER = 0x00000000;
  /* No pull-up, pull-down for PHx pins */
  GPIOH->PUPDR = 0x00000000;

  /* Connect PIx pins to FMC Alternate function */
  GPIOI->AFR[0] = 0xCCCCCCCC;
  GPIOI->AFR[1] = 0x00000CC0;
  /* Configure PIx pins in Alternate function mode */
  GPIOI->MODER = 0x0028AAAA;
  /* Configure PIx pins speed to 50 MHz */
  GPIOI->OSPEEDR = 0x0028AAAA;
  /* Configure PIx pins Output type to push-pull */
  GPIOI->OTYPER = 0x00000000;
  /* No pull-up, pull-down for PIx pins */
  GPIOI->PUPDR = 0x00000000;

  /*-- FMC Configuration ------------------------------------------------------*/
  /* Enable the FMC interface clock */
  RCC->AHB3ENR |= 0x00000001;

  /* Configure and enable SDRAM bank1 */
  FMC_Bank5_6->SDCR[0] = 0x000039D0;
  FMC_Bank5_6->SDTR[0] = 0x01115351;

  /* SDRAM initialization sequence */
  /* Clock enable command */
  FMC_Bank5_6->SDCMR = 0x00000011;
  tmpreg = FMC_Bank5_6->SDSR & 0x00000020;
  while ((tmpreg != 0) & (timeout-- > 0))
  {
    tmpreg = FMC_Bank5_6->SDSR & 0x00000020;
  }

  /* Delay */
  for (index = 0; index < 1000; index++)
    ;

  /* PALL command */
  FMC_Bank5_6->SDCMR = 0x00000012;
  timeout = 0xFFFF;
  while ((tmpreg != 0) & (timeout-- > 0))
  {
    tmpreg = FMC_Bank5_6->SDSR & 0x00000020;
  }

  /* Auto refresh command */
  FMC_Bank5_6->SDCMR = 0x00000073;
  timeout = 0xFFFF;
  while ((tmpreg != 0) & (timeout-- > 0))
  {
    tmpreg = FMC_Bank5_6->SDSR & 0x00000020;
  }

  /* MRD register program */
  FMC_Bank5_6->SDCMR = 0x00046014;
  timeout = 0xFFFF;
  while ((tmpreg != 0) & (timeout-- > 0))
  {
    tmpreg = FMC_Bank5_6->SDSR & 0x00000020;
  }

  /* Set refresh count */
  tmpreg = FMC_Bank5_6->SDRTR;
  FMC_Bank5_6->SDRTR = (tmpreg | (0x0000027C << 1));

  /* Disable write protection */
  tmpreg = FMC_Bank5_6->SDCR[0];
  FMC_Bank5_6->SDCR[0] = (tmpreg & 0xFFFFFDFF);

  /*
    Bank1_SDRAM is configured as follow:

    FMC_SDRAMTimingInitStructure.FMC_LoadToActiveDelay = 2;
    FMC_SDRAMTimingInitStructure.FMC_ExitSelfRefreshDelay = 6;
    FMC_SDRAMTimingInitStructure.FMC_SelfRefreshTime = 4;
    FMC_SDRAMTimingInitStructure.FMC_RowCycleDelay = 6;
    FMC_SDRAMTimingInitStructure.FMC_WriteRecoveryTime = 2;
    FMC_SDRAMTimingInitStructure.FMC_RPDelay = 2;
    FMC_SDRAMTimingInitStructure.FMC_RCDDelay = 2;

    FMC_SDRAMInitStructure.FMC_Bank = SDRAM_BANK;
    FMC_SDRAMInitStructure.FMC_ColumnBitsNumber = FMC_ColumnBits_Number_8b;
    FMC_SDRAMInitStructure.FMC_RowBitsNumber = FMC_RowBits_Number_11b;
    FMC_SDRAMInitStructure.FMC_SDMemoryDataWidth = FMC_SDMemory_Width_16b;
    FMC_SDRAMInitStructure.FMC_InternalBankNumber = FMC_InternalBank_Number_4;
    FMC_SDRAMInitStructure.FMC_CASLatency = FMC_CAS_Latency_3;
    FMC_SDRAMInitStructure.FMC_WriteProtection = FMC_Write_Protection_Disable;
    FMC_SDRAMInitStructure.FMC_SDClockPeriod = FMC_SDClock_Period_2;
    FMC_SDRAMInitStructure.FMC_ReadBurst = FMC_Read_Burst_disable;
    FMC_SDRAMInitStructure.FMC_ReadPipeDelay = FMC_ReadPipe_Delay_1;
    FMC_SDRAMInitStructure.FMC_SDRAMTimingStruct = &FMC_SDRAMTimingInitStructure;
  */
}
#endif /* DATA_IN_ExtSDRAM && DATA_IN_ExtSRAM */

/**
 * @}
 */

/**
 * @}
 */

/**
 * @}
 */