Flash Sector Erase - STM32F207

[Anvi]

Hello, I currently have this code setup to erase a specific sector of the STM32F207 internal flash:

static void eraseSector(uint32_t sector)
{
    FLASH_EraseInitTypeDef eraseInitStruct = { 0 };
    HAL_StatusTypeDef status = HAL_OK;
 
    if( HAL_FLASH_Unlock() != HAL_OK )
    {
        printDebug("Error unlocking Flash\r\n");
    }
 
    eraseInitStruct.TypeErase = TYPEERASE_SECTORS;
    eraseInitStruct.VoltageRange = VOLTAGE_RANGE_3;
    eraseInitStruct.Sector = sector;
    eraseInitStruct.NbSectors = 1;
 
    status = HAL_FLASHEx_Erase_IT(&eraseInitStruct);
    if (status != HAL_OK)
    {
        print("Unable to erase Sector: %d\n", status);
    }
    else
    {
        print("Flash sector %d erased. Status: %d\n", sector, status);
    }
 
    /* Wait for the erase operation to complete */
    osSemaphoreWait(FlashOperation_sem, osWaitForever);
 
    if( HAL_FLASH_Lock() != HAL_OK )
    {
        print("Error locking Flash\n");
    }
}

When this code executes, the application resets whenever the FLASH_CR Start bit is set in the FLASH_Erase_Sector() (called from the HAL_FLASHEx_Erase_IT function). I've attempted this with multiple unused flash sectors and they all crash.

I've also attempted directly call the FLASH_Erase_Sector() and the same persists.

[Uwe Bonnes · Accepted solution]

Maybe some watchdog running?

[TDK]

After the chip resets unexpectedly, look in the RCC_CSR to see the reason for the reset.

[Anvi]

It was indeed the watchdog. Terrible oversight on my part. Thanks for the help!