CODEWITHSUNDEEP
stm32f4
Marcin Gajewski
Marcin Gajewski

Reputation: 61

STM32F429 FMC SDRAM issue when column adress > 8bit

I have the issue with FMC controller when interfacing 64MB IS42S16400J-7BLI. I'm using the CubeMX to set base configuration

static void MX_FMC_Init(void)
{
  FMC_SDRAM_TimingTypeDef SdramTiming;

  /** Perform the SDRAM1 memory initialization sequence
  */
  hsdram1.Instance = FMC_SDRAM_DEVICE;
  /* hsdram1.Init */
  hsdram1.Init.SDBank = FMC_SDRAM_BANK1;
  hsdram1.Init.ColumnBitsNumber = FMC_SDRAM_COLUMN_BITS_NUM_11;
  hsdram1.Init.RowBitsNumber = FMC_SDRAM_ROW_BITS_NUM_12;
  hsdram1.Init.MemoryDataWidth = FMC_SDRAM_MEM_BUS_WIDTH_16;
  hsdram1.Init.InternalBankNumber = FMC_SDRAM_INTERN_BANKS_NUM_4;
  hsdram1.Init.CASLatency = FMC_SDRAM_CAS_LATENCY_3;
  hsdram1.Init.WriteProtection = FMC_SDRAM_WRITE_PROTECTION_DISABLE;
  hsdram1.Init.SDClockPeriod = FMC_SDRAM_CLOCK_PERIOD_2;
  hsdram1.Init.ReadBurst = FMC_SDRAM_RBURST_DISABLE;
  hsdram1.Init.ReadPipeDelay = FMC_SDRAM_RPIPE_DELAY_0;
  /* SdramTiming */
  SdramTiming.LoadToActiveDelay = 2;
  SdramTiming.ExitSelfRefreshDelay = 7;
  SdramTiming.SelfRefreshTime = 4;
  SdramTiming.RowCycleDelay = 7;
  SdramTiming.WriteRecoveryTime = 3;
  SdramTiming.RPDelay = 2;
  SdramTiming.RCDDelay = 2;

  if (HAL_SDRAM_Init(&hsdram1, &SdramTiming) != HAL_OK)
  {
    Error_Handler();
  }

}

and config the memory

void SDRAM_Initialization_Sequence(SDRAM_HandleTypeDef* hsdram, FMC_SDRAM_CommandTypeDef* Command)
{
    __IO uint32_t tmpmrd = 0;
    /* Step 3:  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, 0x1000);

    /* Step 4: Insert 100 ms delay */
    HAL_Delay(100);

    /* Step 5: 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, 0x1000);

    /* Step 6 : Configure a Auto-Refresh command */
    Command->CommandMode           = FMC_SDRAM_CMD_AUTOREFRESH_MODE;
    Command->CommandTarget         = FMC_SDRAM_CMD_TARGET_BANK1;
    Command->AutoRefreshNumber     = 4;
    Command->ModeRegisterDefinition = 0;

    /* Send the command */
    HAL_SDRAM_SendCommand(hsdram, Command, 0x1000);

    /* Step 7: Program the external memory mode register */
    tmpmrd = (uint32_t)SDRAM_MODEREG_BURST_LENGTH_2          |
             SDRAM_MODEREG_BURST_TYPE_SEQUENTIAL   |
             SDRAM_MODEREG_CAS_LATENCY_3           |
             SDRAM_MODEREG_OPERATING_MODE_STANDARD |
             SDRAM_MODEREG_WRITEBURST_MODE_SINGLE;

    Command->CommandMode = FMC_SDRAM_CMD_LOAD_MODE;
    Command->CommandTarget         = FMC_SDRAM_CMD_TARGET_BANK1;
    Command->AutoRefreshNumber     = 1;
    Command->ModeRegisterDefinition = tmpmrd;

    /* Send the command */
    HAL_SDRAM_SendCommand(hsdram, Command, 0x1000);

    /* Step 8: Set the refresh rate counter */
    /* (15.62 us x Freq) - 20 */
    /* Set the device refresh counter */
    HAL_SDRAM_ProgramRefreshRate(hsdram, REFRESH_COUNT);
}

The memory and micro are connected according to the schematicSTM32F429 and SDRAM physical connection I can use only 8bit of addressing. In this configuration everything is perfect, i.e. I can read/write values and observe them in debug window. It limits me though to only 8MB of memory.

When I modify in settings 8bits up to 9/10/11bits to have more memory available it starts malfunctioning,i.e. garbage in some memory area. 8bit adressing vs 11bit adressing

I made customized board, but the same issue you going find on the STM32F429-disco board. So I reject rather the connections. I tried to play with the time delays like "Row to column delay" and increase all delays possible, but not luck. Any help would be appreciated.

Upvotes: 0

Views: 2723

Answers (1)

Konstantin Sachkov
Konstantin Sachkov

Reputation: 21

From IS42S16400J-7BLI datasheet:

Internally configured as a quad-bank DRAM with a synchronous interface. Each 16,777,216-bit bank is organized as 4,096 rows by 256 columns by 16 bits.

So, you should use 8 bit in ColumnBitsNumber. And you'll get 8 Mbytes (64 MBits/8) of memory.

Upvotes: 2

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