path: root/boards/base/STM32F746-Discovery/stm32f746g_discovery_sdram.c

#include "../../../gfx.h"
#if GFX_COMPAT_V2 && GFX_COMPAT_OLDCOLORS
	#undef Red
	#undef Green
	#undef Blue
#endif
#include "stm32f746g_discovery_sdram.h"
#include "stm32f7xx_hal_rcc.h"
#include "stm32f7xx_hal_dma.h"
#include "stm32f7xx_hal_gpio.h"
#include "stm32f7xx_hal_sdram.h"

#if GFX_USE_OS_CHIBIOS
	#define HAL_GPIO_Init(port, ptr)	palSetGroupMode(port, (ptr)->Pin, 0, (ptr)->Mode|((ptr)->Speed<<3)|((ptr)->Pull<<5)|((ptr)->Alternate<<7))
#endif

#define SDRAM_MEMORY_WIDTH               FMC_SDRAM_MEM_BUS_WIDTH_16
#define SDCLOCK_PERIOD                   FMC_SDRAM_CLOCK_PERIOD_2
#define REFRESH_COUNT                    ((uint32_t)0x0603)   /* SDRAM refresh counter (100Mhz SD clock) */
#define SDRAM_TIMEOUT                    ((uint32_t)0xFFFF)

/* DMA definitions for SDRAM DMA transfer */
#define __DMAx_CLK_ENABLE                 __HAL_RCC_DMA2_CLK_ENABLE
#define SDRAM_DMAx_CHANNEL                DMA_CHANNEL_0
#define SDRAM_DMAx_STREAM                 DMA2_Stream0
#define SDRAM_DMAx_IRQn                   DMA2_Stream0_IRQn

/* FMC SDRAM Mode definition register defines */
#define SDRAM_MODEREG_BURST_LENGTH_1             ((uint16_t)0x0000)
#define SDRAM_MODEREG_BURST_LENGTH_2             ((uint16_t)0x0001)
#define SDRAM_MODEREG_BURST_LENGTH_4             ((uint16_t)0x0002)
#define SDRAM_MODEREG_BURST_LENGTH_8             ((uint16_t)0x0004)
#define SDRAM_MODEREG_BURST_TYPE_SEQUENTIAL      ((uint16_t)0x0000)
#define SDRAM_MODEREG_BURST_TYPE_INTERLEAVED     ((uint16_t)0x0008)
#define SDRAM_MODEREG_CAS_LATENCY_2              ((uint16_t)0x0020)
#define SDRAM_MODEREG_CAS_LATENCY_3              ((uint16_t)0x0030)
#define SDRAM_MODEREG_OPERATING_MODE_STANDARD    ((uint16_t)0x0000)
#define SDRAM_MODEREG_WRITEBURST_MODE_PROGRAMMED ((uint16_t)0x0000)
#define SDRAM_MODEREG_WRITEBURST_MODE_SINGLE     ((uint16_t)0x0200)

static void BSP_SDRAM_Initialization_sequence(SDRAM_HandleTypeDef *hsdram, uint32_t RefreshCount);
static void BSP_SDRAM_MspInit(SDRAM_HandleTypeDef  *hsdram);
static void _HAL_SDRAM_Init(SDRAM_HandleTypeDef *hsdram, FMC_SDRAM_TimingTypeDef *Timing);
static HAL_StatusTypeDef _FMC_SDRAM_Init(FMC_SDRAM_TypeDef *Device, FMC_SDRAM_InitTypeDef *Init);
static HAL_StatusTypeDef _FMC_SDRAM_Timing_Init(FMC_SDRAM_TypeDef *Device, FMC_SDRAM_TimingTypeDef *Timing, uint32_t Bank);
static HAL_StatusTypeDef _FMC_SDRAM_SendCommand(FMC_SDRAM_TypeDef *Device, FMC_SDRAM_CommandTypeDef *Command, uint32_t Timeout);
static HAL_StatusTypeDef _FMC_SDRAM_ProgramRefreshRate(FMC_SDRAM_TypeDef *Device, uint32_t RefreshRate);

static void _HAL_SDRAM_Init(SDRAM_HandleTypeDef *hsdram, FMC_SDRAM_TimingTypeDef *Timing)
{
  /* Check the SDRAM handle parameter */
  if(hsdram == NULL)
    return;

  if(hsdram->State == HAL_SDRAM_STATE_RESET)
  {
    /* Allocate lock resource and initialize it */
    hsdram->Lock = HAL_UNLOCKED;
  }

  /* Initialize the SDRAM controller state */
  hsdram->State = HAL_SDRAM_STATE_BUSY;

  /* Initialize SDRAM control Interface */
  _FMC_SDRAM_Init(hsdram->Instance, &(hsdram->Init));

  /* Initialize SDRAM timing Interface */
  _FMC_SDRAM_Timing_Init(hsdram->Instance, Timing, hsdram->Init.SDBank);

  /* Update the SDRAM controller state */
  hsdram->State = HAL_SDRAM_STATE_READY;
}

static HAL_StatusTypeDef _FMC_SDRAM_Init(FMC_SDRAM_TypeDef *Device, FMC_SDRAM_InitTypeDef *Init)
{
  uint32_t tmpr1 = 0;
  uint32_t tmpr2 = 0;

  /* Set SDRAM bank configuration parameters */
  if (Init->SDBank != FMC_SDRAM_BANK2)
  {
    tmpr1 = Device->SDCR[FMC_SDRAM_BANK1];

    /* Clear NC, NR, MWID, NB, CAS, WP, SDCLK, RBURST, and RPIPE bits */
    tmpr1 &= ((uint32_t)~(FMC_SDCR1_NC  | FMC_SDCR1_NR | FMC_SDCR1_MWID | \
                         FMC_SDCR1_NB  | FMC_SDCR1_CAS | FMC_SDCR1_WP | \
                         FMC_SDCR1_SDCLK | FMC_SDCR1_RBURST | FMC_SDCR1_RPIPE));

    tmpr1 |= (uint32_t)(Init->ColumnBitsNumber   |\
                        Init->RowBitsNumber      |\
                        Init->MemoryDataWidth    |\
                        Init->InternalBankNumber |\
                        Init->CASLatency         |\
                        Init->WriteProtection    |\
                        Init->SDClockPeriod      |\
                        Init->ReadBurst          |\
                        Init->ReadPipeDelay
                        );
    Device->SDCR[FMC_SDRAM_BANK1] = tmpr1;
  }
  else /* FMC_Bank2_SDRAM */
  {
    tmpr1 = Device->SDCR[FMC_SDRAM_BANK1];

    /* Clear NC, NR, MWID, NB, CAS, WP, SDCLK, RBURST, and RPIPE bits */
    tmpr1 &= ((uint32_t)~(FMC_SDCR1_NC  | FMC_SDCR1_NR | FMC_SDCR1_MWID | \
                          FMC_SDCR1_NB  | FMC_SDCR1_CAS | FMC_SDCR1_WP | \
                          FMC_SDCR1_SDCLK | FMC_SDCR1_RBURST | FMC_SDCR1_RPIPE));

    tmpr1 |= (uint32_t)(Init->SDClockPeriod      |\
                        Init->ReadBurst          |\
                        Init->ReadPipeDelay);

    tmpr2 = Device->SDCR[FMC_SDRAM_BANK2];

    /* Clear NC, NR, MWID, NB, CAS, WP, SDCLK, RBURST, and RPIPE bits */
    tmpr2 &= ((uint32_t)~(FMC_SDCR1_NC  | FMC_SDCR1_NR | FMC_SDCR1_MWID | \
                          FMC_SDCR1_NB  | FMC_SDCR1_CAS | FMC_SDCR1_WP | \
                          FMC_SDCR1_SDCLK | FMC_SDCR1_RBURST | FMC_SDCR1_RPIPE));

    tmpr2 |= (uint32_t)(Init->ColumnBitsNumber   |\
                       Init->RowBitsNumber      |\
                       Init->MemoryDataWidth    |\
                       Init->InternalBankNumber |\
                       Init->CASLatency         |\
                       Init->WriteProtection);

    Device->SDCR[FMC_SDRAM_BANK1] = tmpr1;
    Device->SDCR[FMC_SDRAM_BANK2] = tmpr2;
  }

  return HAL_OK;
}

static HAL_StatusTypeDef _FMC_SDRAM_Timing_Init(FMC_SDRAM_TypeDef *Device, FMC_SDRAM_TimingTypeDef *Timing, uint32_t Bank)
{
  uint32_t tmpr1 = 0;
  uint32_t tmpr2 = 0;

  /* Set SDRAM device timing parameters */
  if (Bank != FMC_SDRAM_BANK2)
  {
    tmpr1 = Device->SDTR[FMC_SDRAM_BANK1];

    /* Clear TMRD, TXSR, TRAS, TRC, TWR, TRP and TRCD bits */
    tmpr1 &= ((uint32_t)~(FMC_SDTR1_TMRD  | FMC_SDTR1_TXSR | FMC_SDTR1_TRAS | \
                          FMC_SDTR1_TRC  | FMC_SDTR1_TWR | FMC_SDTR1_TRP | \
                          FMC_SDTR1_TRCD));

    tmpr1 |= (uint32_t)(((Timing->LoadToActiveDelay)-1)           |\
                       (((Timing->ExitSelfRefreshDelay)-1) << 4) |\
                       (((Timing->SelfRefreshTime)-1) << 8)      |\
                       (((Timing->RowCycleDelay)-1) << 12)       |\
                       (((Timing->WriteRecoveryTime)-1) <<16)    |\
                       (((Timing->RPDelay)-1) << 20)             |\
                       (((Timing->RCDDelay)-1) << 24));
    Device->SDTR[FMC_SDRAM_BANK1] = tmpr1;
  }
  else /* FMC_Bank2_SDRAM */
  {
    tmpr1 = Device->SDTR[FMC_SDRAM_BANK2];

    /* Clear TMRD, TXSR, TRAS, TRC, TWR, TRP and TRCD bits */
    tmpr1 &= ((uint32_t)~(FMC_SDTR1_TMRD  | FMC_SDTR1_TXSR | FMC_SDTR1_TRAS | \
                          FMC_SDTR1_TRC  | FMC_SDTR1_TWR | FMC_SDTR1_TRP | \
                          FMC_SDTR1_TRCD));

    tmpr1 |= (uint32_t)(((Timing->LoadToActiveDelay)-1)           |\
                       (((Timing->ExitSelfRefreshDelay)-1) << 4) |\
                       (((Timing->SelfRefreshTime)-1) << 8)      |\
                       (((Timing->WriteRecoveryTime)-1) <<16)    |\
                       (((Timing->RCDDelay)-1) << 24));

    tmpr2 = Device->SDTR[FMC_SDRAM_BANK1];

    /* Clear TMRD, TXSR, TRAS, TRC, TWR, TRP and TRCD bits */
    tmpr2 &= ((uint32_t)~(FMC_SDTR1_TMRD  | FMC_SDTR1_TXSR | FMC_SDTR1_TRAS | \
                          FMC_SDTR1_TRC  | FMC_SDTR1_TWR | FMC_SDTR1_TRP | \
                          FMC_SDTR1_TRCD));
    tmpr2 |= (uint32_t)((((Timing->RowCycleDelay)-1) << 12)       |\
                        (((Timing->RPDelay)-1) << 20));

    Device->SDTR[FMC_SDRAM_BANK2] = tmpr1;
    Device->SDTR[FMC_SDRAM_BANK1] = tmpr2;
  }

  return HAL_OK;
}

/**
  * @brief  Initializes the SDRAM device.
  * @retval SDRAM status
  */
void BSP_SDRAM_Init(void)
{ 
  SDRAM_HandleTypeDef sdramHandle;
  FMC_SDRAM_TimingTypeDef Timing;

  /* SDRAM device configuration */
  sdramHandle.Instance = FMC_SDRAM_DEVICE;
    
  /* Timing configuration for 100Mhz as SD clock frequency (System clock is up to 200Mhz) */
  Timing.LoadToActiveDelay    = 2;
  Timing.ExitSelfRefreshDelay = 7;
  Timing.SelfRefreshTime      = 4;
  Timing.RowCycleDelay        = 7;
  Timing.WriteRecoveryTime    = 2;
  Timing.RPDelay              = 2;
  Timing.RCDDelay             = 2;
  
  sdramHandle.Init.SDBank             = FMC_SDRAM_BANK1;
  sdramHandle.Init.ColumnBitsNumber   = FMC_SDRAM_COLUMN_BITS_NUM_8;
  sdramHandle.Init.RowBitsNumber      = FMC_SDRAM_ROW_BITS_NUM_12;
  sdramHandle.Init.MemoryDataWidth    = SDRAM_MEMORY_WIDTH;
  sdramHandle.Init.InternalBankNumber = FMC_SDRAM_INTERN_BANKS_NUM_4;
  sdramHandle.Init.CASLatency         = FMC_SDRAM_CAS_LATENCY_2;
  sdramHandle.Init.WriteProtection    = FMC_SDRAM_WRITE_PROTECTION_DISABLE;
  sdramHandle.Init.SDClockPeriod      = SDCLOCK_PERIOD;
  sdramHandle.Init.ReadBurst          = FMC_SDRAM_RBURST_ENABLE;
  sdramHandle.Init.ReadPipeDelay      = FMC_SDRAM_RPIPE_DELAY_0;
  
  /* SDRAM controller initialization */

  BSP_SDRAM_MspInit(&sdramHandle);

  _HAL_SDRAM_Init(&sdramHandle, &Timing);
  
  /* SDRAM initialization sequence */
  BSP_SDRAM_Initialization_sequence(&sdramHandle, REFRESH_COUNT);
}

static HAL_StatusTypeDef _HAL_SDRAM_SendCommand(SDRAM_HandleTypeDef *hsdram, FMC_SDRAM_CommandTypeDef *Command, uint32_t Timeout)
{
  /* Check the SDRAM controller state */
  if(hsdram->State == HAL_SDRAM_STATE_BUSY)
  {
    return HAL_BUSY;
  }

  /* Update the SDRAM state */
  hsdram->State = HAL_SDRAM_STATE_BUSY;

  /* Send SDRAM command */
  _FMC_SDRAM_SendCommand(hsdram->Instance, Command, Timeout);

  /* Update the SDRAM controller state state */
  if(Command->CommandMode == FMC_SDRAM_CMD_PALL)
  {
    hsdram->State = HAL_SDRAM_STATE_PRECHARGED;
  }
  else
  {
    hsdram->State = HAL_SDRAM_STATE_READY;
  }

  return HAL_OK;
}

static HAL_StatusTypeDef _FMC_SDRAM_SendCommand(FMC_SDRAM_TypeDef *Device, FMC_SDRAM_CommandTypeDef *Command, uint32_t Timeout)
{
  __IO uint32_t tmpr = 0;
  systemticks_t tickstart = 0;

  /* Set command register */
  tmpr = (uint32_t)((Command->CommandMode)                  |\
                    (Command->CommandTarget)                |\
                    (((Command->AutoRefreshNumber)-1) << 5) |\
                    ((Command->ModeRegisterDefinition) << 9)
                    );

  Device->SDCMR = tmpr;

  /* Get tick */
  tickstart = gfxSystemTicks();

  /* wait until command is send */
  while(HAL_IS_BIT_SET(Device->SDSR, FMC_SDSR_BUSY))
  {
    /* Check for the Timeout */
    if(Timeout != HAL_MAX_DELAY)
    {
      if((Timeout == 0)||((gfxSystemTicks() - tickstart ) > Timeout))
      {
        return HAL_TIMEOUT;
      }
    }

    return HAL_ERROR;
  }

  return HAL_OK;
}

static HAL_StatusTypeDef _HAL_SDRAM_ProgramRefreshRate(SDRAM_HandleTypeDef *hsdram, uint32_t RefreshRate)
{
  /* Check the SDRAM controller state */
  if(hsdram->State == HAL_SDRAM_STATE_BUSY)
  {
    return HAL_BUSY;
  }

  /* Update the SDRAM state */
  hsdram->State = HAL_SDRAM_STATE_BUSY;

  /* Program the refresh rate */
  _FMC_SDRAM_ProgramRefreshRate(hsdram->Instance ,RefreshRate);

  /* Update the SDRAM state */
  hsdram->State = HAL_SDRAM_STATE_READY;

  return HAL_OK;
}

static HAL_StatusTypeDef _FMC_SDRAM_ProgramRefreshRate(FMC_SDRAM_TypeDef *Device, uint32_t RefreshRate)
{
  /* Set the refresh rate in command register */
  Device->SDRTR |= (RefreshRate<<1);

  return HAL_OK;
}

static HAL_StatusTypeDef _HAL_DMA_Init(DMA_HandleTypeDef *hdma)
{
  uint32_t tmp = 0;

  /* Check the DMA peripheral state */
  if(hdma == NULL)
  {
    return HAL_ERROR;
  }

  /* Change DMA peripheral state */
  hdma->State = HAL_DMA_STATE_BUSY;

  /* Get the CR register value */
  tmp = hdma->Instance->CR;

  /* Clear CHSEL, MBURST, PBURST, PL, MSIZE, PSIZE, MINC, PINC, CIRC, DIR, CT and DBM bits */
  tmp &= ((uint32_t)~(DMA_SxCR_CHSEL | DMA_SxCR_MBURST | DMA_SxCR_PBURST | \
                      DMA_SxCR_PL    | DMA_SxCR_MSIZE  | DMA_SxCR_PSIZE  | \
                      DMA_SxCR_MINC  | DMA_SxCR_PINC   | DMA_SxCR_CIRC   | \
                      DMA_SxCR_DIR   | DMA_SxCR_CT     | DMA_SxCR_DBM));

  /* Prepare the DMA Stream configuration */
  tmp |=  hdma->Init.Channel             | hdma->Init.Direction        |
          hdma->Init.PeriphInc           | hdma->Init.MemInc           |
          hdma->Init.PeriphDataAlignment | hdma->Init.MemDataAlignment |
          hdma->Init.Mode                | hdma->Init.Priority;

  /* the Memory burst and peripheral burst are not used when the FIFO is disabled */
  if(hdma->Init.FIFOMode == DMA_FIFOMODE_ENABLE)
  {
    /* Get memory burst and peripheral burst */
    tmp |=  hdma->Init.MemBurst | hdma->Init.PeriphBurst;
  }

  /* Write to DMA Stream CR register */
  hdma->Instance->CR = tmp;

  /* Get the FCR register value */
  tmp = hdma->Instance->FCR;

  /* Clear Direct mode and FIFO threshold bits */
  tmp &= (uint32_t)~(DMA_SxFCR_DMDIS | DMA_SxFCR_FTH);

  /* Prepare the DMA Stream FIFO configuration */
  tmp |= hdma->Init.FIFOMode;

  /* the FIFO threshold is not used when the FIFO mode is disabled */
  if(hdma->Init.FIFOMode == DMA_FIFOMODE_ENABLE)
  {
    /* Get the FIFO threshold */
    tmp |= hdma->Init.FIFOThreshold;
  }

  /* Write to DMA Stream FCR */
  hdma->Instance->FCR = tmp;

  /* Initialize the error code */
  hdma->ErrorCode = HAL_DMA_ERROR_NONE;

  /* Initialize the DMA state */
  hdma->State = HAL_DMA_STATE_READY;

  return HAL_OK;
}

/**
  * @brief  DeInitializes the DMA peripheral
  * @param  hdma: pointer to a DMA_HandleTypeDef structure that contains
  *               the configuration information for the specified DMA Stream.
  * @retval HAL status
  */
static HAL_StatusTypeDef _HAL_DMA_DeInit(DMA_HandleTypeDef *hdma)
{
  /* Check the DMA peripheral state */
  if(hdma == NULL)
  {
    return HAL_ERROR;
  }

  /* Check the DMA peripheral state */
  if(hdma->State == HAL_DMA_STATE_BUSY)
  {
     return HAL_ERROR;
  }

  /* Disable the selected DMA Streamx */
  __HAL_DMA_DISABLE(hdma);

  /* Reset DMA Streamx control register */
  hdma->Instance->CR   = 0;

  /* Reset DMA Streamx number of data to transfer register */
  hdma->Instance->NDTR = 0;

  /* Reset DMA Streamx peripheral address register */
  hdma->Instance->PAR  = 0;

  /* Reset DMA Streamx memory 0 address register */
  hdma->Instance->M0AR = 0;

  /* Reset DMA Streamx memory 1 address register */
  hdma->Instance->M1AR = 0;

  /* Reset DMA Streamx FIFO control register */
  hdma->Instance->FCR  = (uint32_t)0x00000021;

  /* Clear all flags */
  __HAL_DMA_CLEAR_FLAG(hdma, __HAL_DMA_GET_DME_FLAG_INDEX(hdma));
  __HAL_DMA_CLEAR_FLAG(hdma, __HAL_DMA_GET_TC_FLAG_INDEX(hdma));
  __HAL_DMA_CLEAR_FLAG(hdma, __HAL_DMA_GET_TE_FLAG_INDEX(hdma));
  __HAL_DMA_CLEAR_FLAG(hdma, __HAL_DMA_GET_FE_FLAG_INDEX(hdma));
  __HAL_DMA_CLEAR_FLAG(hdma, __HAL_DMA_GET_HT_FLAG_INDEX(hdma));

  /* Initialize the error code */
  hdma->ErrorCode = HAL_DMA_ERROR_NONE;

  /* Initialize the DMA state */
  hdma->State = HAL_DMA_STATE_RESET;

  /* Release Lock */
  __HAL_UNLOCK(hdma);

  return HAL_OK;
}

/**
  * @brief  Programs the SDRAM device.
  * @param  RefreshCount: SDRAM refresh counter value 
  * @retval None
  */
static void BSP_SDRAM_Initialization_sequence(SDRAM_HandleTypeDef *hsdram, uint32_t RefreshCount)
{
  FMC_SDRAM_CommandTypeDef Command;
  
  /* Step 1: Configure a clock configuration enable command */
  Command.CommandMode            = FMC_SDRAM_CMD_CLK_ENABLE;
  Command.CommandTarget          = FMC_SDRAM_CMD_TARGET_BANK1;
  Command.AutoRefreshNumber      = 1;
  Command.ModeRegisterDefinition = 0;

  /* Send the command */
  _HAL_SDRAM_SendCommand(hsdram, &Command, SDRAM_TIMEOUT);

  /* Step 2: Insert 100 us minimum delay */ 
  /* Inserted delay is equal to 1 ms due to systick time base unit (ms) */
  gfxSleepMilliseconds(1);
    
  /* Step 3: Configure a PALL (precharge all) command */ 
  Command.CommandMode            = FMC_SDRAM_CMD_PALL;
  Command.CommandTarget          = FMC_SDRAM_CMD_TARGET_BANK1;
  Command.AutoRefreshNumber      = 1;
  Command.ModeRegisterDefinition = 0;

  /* Send the command */
  _HAL_SDRAM_SendCommand(hsdram, &Command, SDRAM_TIMEOUT);
  
  /* Step 4: Configure an Auto Refresh command */ 
  Command.CommandMode            = FMC_SDRAM_CMD_AUTOREFRESH_MODE;
  Command.CommandTarget          = FMC_SDRAM_CMD_TARGET_BANK1;
  Command.AutoRefreshNumber      = 8;
  Command.ModeRegisterDefinition = 0;

  /* Send the command */
  _HAL_SDRAM_SendCommand(hsdram, &Command, SDRAM_TIMEOUT);
  
  /* Step 5: Program the external memory mode register */
  Command.CommandMode            = FMC_SDRAM_CMD_LOAD_MODE;
  Command.CommandTarget          = FMC_SDRAM_CMD_TARGET_BANK1;
  Command.AutoRefreshNumber      = 1;
  Command.ModeRegisterDefinition = (uint32_t)SDRAM_MODEREG_BURST_LENGTH_1          |\
          	  	  	  	  	  	  	  	  	  SDRAM_MODEREG_BURST_TYPE_SEQUENTIAL   |\
          	  	  	  	  	  	  	  	  	  SDRAM_MODEREG_CAS_LATENCY_2           |\
          	  	  	  	  	  	  	  	  	  SDRAM_MODEREG_OPERATING_MODE_STANDARD |\
          	  	  	  	  	  	  	  	  	  SDRAM_MODEREG_WRITEBURST_MODE_SINGLE;;

  /* Send the command */
  _HAL_SDRAM_SendCommand(hsdram, &Command, SDRAM_TIMEOUT);
  
  /* Step 6: Set the refresh rate counter */
  /* Set the device refresh rate */
  _HAL_SDRAM_ProgramRefreshRate(hsdram, RefreshCount);
}

/**
  * @brief  Initializes SDRAM MSP.
  * @param  hsdram: SDRAM handle
  * @param  Params
  * @retval None
  */
static void BSP_SDRAM_MspInit(SDRAM_HandleTypeDef  *hsdram)
{  
  static DMA_HandleTypeDef dma_handle;
  GPIO_InitTypeDef gpio_init_structure;
  
  /* Enable FMC clock */
  __HAL_RCC_FMC_CLK_ENABLE();
  
  /* Enable chosen DMAx clock */
  __DMAx_CLK_ENABLE();

  /* Enable GPIOs clock */
  __HAL_RCC_GPIOC_CLK_ENABLE();
  __HAL_RCC_GPIOD_CLK_ENABLE();
  __HAL_RCC_GPIOE_CLK_ENABLE();
  __HAL_RCC_GPIOF_CLK_ENABLE();
  __HAL_RCC_GPIOG_CLK_ENABLE();
  __HAL_RCC_GPIOH_CLK_ENABLE();
  
  /* Common GPIO configuration - some are already setup by ChibiOS Init */
  gpio_init_structure.Mode      = GPIO_MODE_AF_PP;
  gpio_init_structure.Pull      = GPIO_PULLUP;
  gpio_init_structure.Speed     = GPIO_SPEED_FAST;
  gpio_init_structure.Alternate = GPIO_AF12_FMC;
  
  /* GPIOC configuration */
  gpio_init_structure.Pin   = GPIO_PIN_3;
  HAL_GPIO_Init(GPIOC, &gpio_init_structure);

  /* GPIOD configuration */
  gpio_init_structure.Pin   = GPIO_PIN_0 | GPIO_PIN_1 | GPIO_PIN_3 | GPIO_PIN_8 | GPIO_PIN_9 |
                              GPIO_PIN_10 | GPIO_PIN_14 | GPIO_PIN_15;
  HAL_GPIO_Init(GPIOD, &gpio_init_structure);

  /* GPIOE configuration */  
  gpio_init_structure.Pin   = GPIO_PIN_0 | GPIO_PIN_1 | GPIO_PIN_7| GPIO_PIN_8 | GPIO_PIN_9 |\
                              GPIO_PIN_10 | GPIO_PIN_11 | GPIO_PIN_12 | GPIO_PIN_13 | GPIO_PIN_14 |\
                              GPIO_PIN_15;
  HAL_GPIO_Init(GPIOE, &gpio_init_structure);
  
  /* GPIOF configuration */  
  gpio_init_structure.Pin   = GPIO_PIN_0 | GPIO_PIN_1 | GPIO_PIN_2| GPIO_PIN_3 | GPIO_PIN_4 |\
                              GPIO_PIN_5 | GPIO_PIN_11 | GPIO_PIN_12 | GPIO_PIN_13 | GPIO_PIN_14 |\
                              GPIO_PIN_15;
  HAL_GPIO_Init(GPIOF, &gpio_init_structure);
  
  /* GPIOG configuration */  
  gpio_init_structure.Pin   = GPIO_PIN_0 | GPIO_PIN_1 | GPIO_PIN_4| GPIO_PIN_5 | GPIO_PIN_8 |\
                              GPIO_PIN_15;
  HAL_GPIO_Init(GPIOG, &gpio_init_structure);

  /* GPIOH configuration */  
  gpio_init_structure.Pin   = GPIO_PIN_3 | GPIO_PIN_5;
  HAL_GPIO_Init(GPIOH, &gpio_init_structure); 
  
  /* Configure common DMA parameters */
  dma_handle.Init.Channel             = SDRAM_DMAx_CHANNEL;
  dma_handle.Init.Direction           = DMA_MEMORY_TO_MEMORY;
  dma_handle.Init.PeriphInc           = DMA_PINC_ENABLE;
  dma_handle.Init.MemInc              = DMA_MINC_ENABLE;
  dma_handle.Init.PeriphDataAlignment = DMA_PDATAALIGN_WORD;
  dma_handle.Init.MemDataAlignment    = DMA_MDATAALIGN_WORD;
  dma_handle.Init.Mode                = DMA_NORMAL;
  dma_handle.Init.Priority            = DMA_PRIORITY_HIGH;
  dma_handle.Init.FIFOMode            = DMA_FIFOMODE_DISABLE;         
  dma_handle.Init.FIFOThreshold       = DMA_FIFO_THRESHOLD_FULL;
  dma_handle.Init.MemBurst            = DMA_MBURST_SINGLE;
  dma_handle.Init.PeriphBurst         = DMA_PBURST_SINGLE; 
  
  dma_handle.Instance = SDRAM_DMAx_STREAM;
  
   /* Associate the DMA handle */
  __HAL_LINKDMA(hsdram, hdma, dma_handle);
  
  /* Deinitialize the stream for new transfer */
  _HAL_DMA_DeInit(&dma_handle);
  
  /* Configure the DMA stream */
  _HAL_DMA_Init(&dma_handle);
  
  /* NVIC configuration for DMA transfer complete interrupt */
  NVIC_SetPriority(SDRAM_DMAx_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(), 5, 0));
  /* Enable interrupt */
  NVIC_EnableIRQ(SDRAM_DMAx_IRQn);
}