Use of an external SDRAM (IS42S16320F) with STM32H753

[Gregory3]

Hello!

I'm trying to use an external SDRAM (IS42S16320F) with an STM32H753 but no luck till now.

Could please anyone check if my settings are correct because I don't know if I made a bug here.

 

 

For that I have attached the FMC configuration and the schematic parts with the SDRAM and uC.

I would be very greatefull for that.

Regards,

Gregor

[Gregory3]

Hi!

Here some update for the topic.

I was trying to change the refresh rate according to the proposal to 400:

#define REFRESH_COUNT                    ((uint32_t)0x0190)   /* SDRAM refresh counter (100Mhz SD clock) */

which is set by the last step in the initialization function:

  /* Step 6: Set the refresh rate counter */
  /* Set the device refresh rate */
  HAL_SDRAM_ProgramRefreshRate(hsdram, REFRESH_COUNT);

that runs this one:

HAL_StatusTypeDef FMC_SDRAM_ProgramRefreshRate(FMC_SDRAM_TypeDef *Device, uint32_t RefreshRate)
{
  /* Check the parameters */
  assert_param(IS_FMC_SDRAM_DEVICE(Device));
  assert_param(IS_FMC_REFRESH_RATE(RefreshRate));
 
  /* Set the refresh rate in command register */
  MODIFY_REG(Device->SDRTR, FMC_SDRTR_COUNT, (RefreshRate << FMC_SDRTR_COUNT_Pos));
 
  return HAL_OK;
}

So it should set the SDRTR register to the value 0x0190.

After setting a breakpoint just after this function, the register has a value of 0x0:

 

Now I' checking why this is so, but this dosen't supose to look like this...

[Gregory3]

Hello!

I have found the problem. The reason, why the register was not set, was very easy: I forgot to change in the SDRAM initialization function the number of the SDRAM to 2 (since I'm using the SDRAM2).

You can see here the sdramHandle is set to hsdram2 and everything works fine 🙂

void BSP_SDRAM_Init(void)
{
	sdramHandle = hsdram2;
 
    /* Program the SDRAM external device */
    SDRAM_Initialization_Sequence(&sdramHandle, &command);
 
 
}
 
 
/**
  * @brief  Perform the SDRAM external memory inialization sequence
  * @param  hsdram: SDRAM handle
  * @param  Command: Pointer to SDRAM command structure
  * @retval None
  */
void SDRAM_Initialization_Sequence(SDRAM_HandleTypeDef *hsdram, FMC_SDRAM_CommandTypeDef *Command)
{
  __IO uint32_t tmpmrd =0;
  /* Step 1:  Configure a clock configuration enable command */
  Command->CommandMode = FMC_SDRAM_CMD_CLK_ENABLE;
  Command->CommandTarget = FMC_SDRAM_CMD_TARGET_BANK2;;
  Command->AutoRefreshNumber = 1;
  Command->ModeRegisterDefinition = 0;
 
  /* Send the command */
  HAL_SDRAM_SendCommand(hsdram, Command, SDRAM_TIMEOUT);

I have checked the registers and they are set now correctly.

I also wrote a simple code to do a first test:

• fill Tx Buffer with some numbers
• write Tx_Buffer to SDRAM starting at 0xD000 0000
• read the SDRAM into a Rx_Buffer starting from 0xD000 0000

The result is fine in memory view and variable check:

Thank you all for all the help!

Now I can continue to write my test code.

Regards,

Gregor