FLASH is Zeroed Automatically!

here is a snippet

in main() I read my values

HAL_FLASH_Unlock();
EE_Init();
EE_ReadVariable(CAL_L_m3_FLASH,&flash_buffer_r[CAL_L_m3_FLASH]);

for writing, first I try to erase the whole page using this code

uint32_t PAGEError = 0;
/*Variable used for Erase procedure*/
static FLASH_EraseInitTypeDef EraseInitStruct;
EraseInitStruct.TypeErase = FLASH_TYPEERASE_PAGES;
EraseInitStruct.PageAddress = EEPROM_START_ADDRESS;
EraseInitStruct.NbPages = 1;
											HAL_FLASHEx_Erase(&EraseInitStruct, &PAGEError);

and then in write I use this code

EE_WriteVariable(CAL_L_m3_FLASH,cal_l_m3_d);

which in detail is

uint16_t EE_WriteVariable(uint16_t VirtAddress, volatile uint32_t Data)
{
 uint16_t Status = 0;
	
 /* Write the variable virtual address and value in the EEPROM */
 Status = EE_VerifyPageFullWriteVariable(VirtAddress, Data);
 
 /* In case the EEPROM active page is full */
 if (Status == PAGE_FULL)
 {
 /* Perform Page transfer */
 Status = EE_PageTransfer(VirtAddress, Data);
 }
 
 /* Return last operation status */
 return Status;
}

more detail

static uint16_t EE_VerifyPageFullWriteVariable(uint16_t VirtAddress, uint16_t Data)
{
 HAL_StatusTypeDef flashstatus = HAL_OK;
 uint16_t validpage = PAGE0;
 uint32_t address = EEPROM_START_ADDRESS, pageendaddress = EEPROM_START_ADDRESS+PAGE_SIZE;
 
 /* Get valid Page for write operation */
 validpage = EE_FindValidPage(WRITE_IN_VALID_PAGE);
 
 /* Check if there is no valid page */
 if (validpage == NO_VALID_PAGE)
 {
 return NO_VALID_PAGE;
 }
 
 /* Get the valid Page start address */
 address = (uint32_t)(EEPROM_START_ADDRESS + (uint32_t)(validpage * PAGE_SIZE));
 
 /* Get the valid Page end address */
 pageendaddress = (uint32_t)((EEPROM_START_ADDRESS - 1) + (uint32_t)((validpage + 1) * PAGE_SIZE));
 
 /* Check each active page address starting from begining */
 while (address < pageendaddress)
 {
 /* Verify if address and address+2 contents are 0xFFFFFFFF */
 if ((*(__IO uint32_t*)address) == 0xFFFFFFFF)
 {
 /* Set variable data */
 flashstatus = HAL_FLASH_Program(FLASH_TYPEPROGRAM_HALFWORD, address, Data); 
 /* If program operation was failed, a Flash error code is returned */
 if (flashstatus != HAL_OK)
 {
 return flashstatus;
 }
 /* Set variable virtual address */
 flashstatus = HAL_FLASH_Program(FLASH_TYPEPROGRAM_HALFWORD, address + 2, VirtAddress); 
 /* Return program operation status */
 return flashstatus;
 }
 else
 {
 /* Next address location */
 address = address + 4;
 }
 }
 
 /* Return PAGE_FULL in case the valid page is full */
 return PAGE_FULL;
}

you're right, I should say 0

dear @TDK

yes it still shows 0. even with a restart. seems like when the addresses are 0, they are not 0xFFFFFFFF any more, so not able to write on them and read them 0 as they are zeroed

sounds good! I tried this and I cant recall any good out of it