Posted by nimishjain1000 on 2018-08-31 14:50

Hi all.
I am using stm32h743ii microcontroller and interfaced with an external sdram of 512mb ( micron - MT48LC64M8A2P) .
The initial code and configuration is done using cubeMx . Set the timing parameters by taking the reference of example provided with stm32h7 firmware and from the datasheet.

Initialization of fmc is as follows :
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_13;
hsdram1.Init.MemoryDataWidth = FMC_SDRAM_MEM_BUS_WIDTH_8;
hsdram1.Init.InternalBankNumber = FMC_SDRAM_INTERN_BANKS_NUM_4;
hsdram1.Init.CASLatency = FMC_SDRAM_CAS_LATENCY_2;
hsdram1.Init.WriteProtection = FMC_SDRAM_WRITE_PROTECTION_DISABLE;
hsdram1.Init.SDClockPeriod = FMC_SDRAM_CLOCK_PERIOD_2;
hsdram1.Init.ReadBurst = FMC_SDRAM_RBURST_ENABLE;
hsdram1.Init.ReadPipeDelay = FMC_SDRAM_RPIPE_DELAY_0;
/* SdramTiming */
SdramTiming.LoadToActiveDelay = 3; //2;
SdramTiming.ExitSelfRefreshDelay = 8;
SdramTiming.SelfRefreshTime = 5;
SdramTiming.RowCycleDelay = 7;
SdramTiming.WriteRecoveryTime = 3;
SdramTiming.RPDelay = 2;
SdramTiming.RCDDelay = 2;

if (HAL_SDRAM_Init(&hsdram1, &SdramTiming) != HAL_OK)
{
_Error_Handler(FILE, LINE);
}

}
After this sdram initialization :
static void BSP_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, SDRAM_TIMEOUT);

/* Step 4: Insert 100 us minimum delay */
/* Inserted delay is equal to 1 ms due to systick time base unit (ms) */
HAL_Delay(1);

/* 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, SDRAM_TIMEOUT);

/* Step 6 : Configure a 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 7: Program the external memory mode register */
tmpmrd = (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;

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, SDRAM_TIMEOUT);

/* Step 8: Set the refresh rate counter */
/* (15.62 us x Freq) - 20 */
/* Set the device refresh counter */
hsdram->Instance->SDRTR |= ((uint32_t)((1292)