SDRAM on the STM32F429I-DISC

[DetlefS]

Hi,

I want to fly the STM32F429I-DISC with the 8 MB SDRAM. I use CubeIDE and selected the right board. All units are set to default. I commented out everything that had to do with os.

With help of ChatGPT I hacked together an initialization of the SDRAM and set up a SDRAM Test. That seems to work partly but with weird effects. In the following code: start/end 0x00/0xff or 0x100/0x1ff works fine, but start/end 0x00/0x101 reads out 0x100 at  address 0x0. Maybe it is an timing issue with precharged lines.

THX

Cheers

Detlef

#define SDRAM_BASE_ADDR ((uint32_t)0xD0000000)

void SDRAM_Test(void)

{

volatile uint16_t *p = (volatile uint16_t *)SDRAM_BASE_ADDR;

uint32_t i ;

uint32_t start = 0x100 ;

uint32_t end = 0x302 ;

for (i=start; i<end; i++) p[i] = i;

sprintf(buf,"start \r\n",i);

HAL_UART_Transmit(&huart1, (uint8_t *) buf, strlen(buf), HAL_MAX_DELAY);

while(1){

for (i=start; i<end;i++)

if (p[i] != i){

sprintf(buf,"no 0x%x 0x%x\r\n",i,p[i]);

HAL_UART_Transmit(&huart1, (uint8_t *) buf, strlen(buf), HAL_MAX_DELAY);

}

sprintf(buf,"end \r\n",i);

HAL_UART_Transmit(&huart1, (uint8_t *) buf, strlen(buf), HAL_MAX_DELAY);

}

}

[mƎALLEm]

Hello,

1- In next time please use </> to share a code. Please read How to write your question to maximize your chances to find a solution

I invite you to edit your post to comply with the rule.

Thank you for your understanding.

2- Better to inspire from the SDRAM driver implemented in the BSP : https://github.com/STMicroelectronics/32f429idiscovery-bsp/blob/d77779a2a4e950246752a4397e2adf40c25829f9/stm32f429i_discovery_sdram.c

[Ozone]

I never had a F429 Disco board.
However, I believe to remember it was around the time the first boards were "blessed" with Cube/HAL code instead of the legacy SPL.
I recommend to check if a SPL-based firmware package is available, those always contained driver or example code for onboard peripherals or units like SDRAMs, LCDs, MEMS or audio codecs.
And the SPL is much less awkward and easier to understand.

And even if you choose a new Cube-based example, the config settings of the SPL code can serve as a template.