Does it possible to write a byte of values to the flash memory of STM32F030CC

[PB.4]

Hello all,

Can anyone in his forum to let me know whether can be write a byte in to the flash memory of the STM32F030CC uC, it always asking to increment the the write size as '4' bytes, if I hchange the code to write as a byte or even a two bytes the uC enter into hard fault handler, why? The code is below:

uint32_t Flash_Write_Data (uint32_t StartPageAddress, uint32_t *Data, uint16_t numberofwords)
{
	static FLASH_EraseInitTypeDef EraseInitStruct;
	uint32_t PAGEError;
	int sofar = 0;
 
	/* Unlock the Flash to enable the flash control register access *************/
	HAL_FLASH_Unlock();
 
	/* Erase the user Flash area*/
	uint32_t StartPage = GetPage(StartPageAddress);
	uint32_t EndPageAdress = StartPageAddress + numberofwords*4;
	uint32_t EndPage = GetPage(EndPageAdress);
 
	/* Fill EraseInit structure*/
	EraseInitStruct.TypeErase   = FLASH_TYPEERASE_PAGES;
	EraseInitStruct.PageAddress = StartPage;
	EraseInitStruct.NbPages     = ((EndPage - StartPage)/FLASH_PAGE_SIZE) +1;
 
 
	   if (HAL_FLASHEx_Erase(&EraseInitStruct, &PAGEError) != HAL_OK)
	   {
		 /*Error occurred while page erase.*/
		  return HAL_FLASH_GetError ();
	   }
 
	   /* Program the user Flash area word by word*/
 
	   while (sofar < numberofwords)
	   {
		 if (HAL_FLASH_Program(FLASH_TYPEPROGRAM_WORD, StartPageAddress, Data[sofar]) == HAL_OK)
		 {
			 StartPageAddress += 4;  // use StartPageAddress += 2 for half word and 8 for double word
			 sofar++;
		 }
		 else
		 {
		   /* Error occurred while writing data in Flash memory*/
			 return HAL_FLASH_GetError ();
		 }
	   }
 
	   /* Lock the Flash to disable the flash control register access (recommended
		  to protect the FLASH memory against possible unwanted operation) *********/
	   HAL_FLASH_Lock();
 
	   return 0;
}

[KnarfB]

The reference manual says:

"The main Flash memory can be programmed 16 bits at a time. The program operation is started when the CPU writes a half-word into a main Flash memory address with the PG bit of the FLASH_CR register set. Any attempt to write data that are not half-word long will result in a bus error generating a Hard Fault interrupt."

Programming 16 Bits work if you use FLASH_TYPEPROGRAM_HALFWORD in your above code.

If you have to write several small pieces of data repeatedly, you might want to look into eeprom emulation code.

hth

KnarfB

[Tesla DeLorean]

Cortex-M0 will fault if you do unaligned reads or writes.

`Write structures as blocks of words, or come up with a different strategy to write/journal data into Flash sector(s)