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);

}

}