Minimal Write Single Byte to Flash EDATA on H533

[TG_APCD]

I am trying to write a single byte of data to the start of the EDATA area on the H533

I have the EDATA Sector 1 set to active via the option bytes.

static FLASH_EraseInitTypeDef EraseInitStruct;
uint32_t flash_sector_error;
EraseInitStruct.Banks = FLASH_BANK_1;
EraseInitStruct.TypeErase = FLASH_TYPEERASE_SECTORS;
EraseInitStruct.Sector        = 24;
EraseInitStruct.Banks     = FLASH_BANK_1;
EraseInitStruct.NbSectors     =1;

HAL_FLASH_Unlock();
if (HAL_FLASHEx_Erase(&EraseInitStruct, &flash_sector_error) != HAL_OK){
	SEND_STRING("FLASH ERASE FAIL\r\n");
}

//HARDFAULT OCCURS HERE |V|
if(HAL_FLASH_Program(FLASH_TYPEPROGRAM_WORD_EDATA, 0x08030000, (uint32_t ) 43210) != HAL_OK){
	SEND_STRING("FLASH WRITE FAIL\r\n");
}
HAL_FLASH_Lock();

 From my understanding in the reference manual the EDATA starts at 8030000 and is in sector 24 of bank 1. 

The erase option works fine, but the HAL_FLASH_Program operation always causes a hard fault.

Suggestions? Next Steps for debugging?

[Sarra.S]

Hello @TG_APCD, 

If you read a flash high-cycle data not previously written, a double ECC error is reported and only a word full of set bits is returned. The ECC correction reports a double-error detection (ECCD) and ECCD implies an NMI raised. 

Check this article: How to avoid a HardFault when ICACHE is enabled on the STM32H5 series

[TG_APCD]

Thanks, I'm not reading the region, I am erasing and then programming it. 

I read through the linked article, and based on that I went and checked all the FLASH error registers to see if there were any flags raised following the fault.

I checked the NSCR, SECCR, NSSR, and the ECCDETR registers and didn't see any error flags raised there.

This is the state of the FLASH registers immediately following the hard fault.

ACR			0x1 	
NSKEYR			0x0 	
SECKEYR			0x0 	
OPTKEYR			0x0 	
NSOBKKEYR			0x0 	
SECOBKKEYR			0x0 	
OPSR			0x0 	
OPTCR			0x1 	
NSSR			0x0 	
SECSR			0x0 	
NSCR			0x602 	
SECCR			0x0 	
NSCCR			0x0 	
SECCCR			0x0 	

	
PRIVCFGR			0x0 	
NSOBKCFGR			0x1ff0001 	
SECOBKCFGR			0x0 	
HDPEXTR			0x0 	
	
OPTSR_CUR			0x2d30edf8 	
OPTSR_PRG			0x2d30edf8 	

NSEPOCHR_CUR			0x1 	
NSEPOCHR_PRG			0x0 	
SECEPOCHR_CUR			0x1 	
SECEPOCHR_PRG			0x0 	
OPTSR2_CUR			0xc300015c 	
OPTSR2_PRG			0xc300015c 	


NSBOOTR_CUR			0x80000c3 	
NSBOOTR_PRG			0x80000c3 	
SECBOOTR_CUR			0x0 	
SECBOOTR_PRG			0x0 	
OTPBLR_CUR			0x0 	
OTPBLR_PRG			0x0 	

SECBB1R1			0x0 	
	
PRIVBB1R1			0x0 	

SECWM1R_CUR			0x7 	
SECWM1R_PRG			0x0 	
WRP1R_CUR			0xff 	
WRP1R_PRG			0xff 	
EDATA1R_CUR			0x0 	
EDATA1R_PRG			0x8000 	
HDP1R_CUR			0x1 	
HDP1R_PRG			0x1 	
ECCCORR			0x0 	
ECCDETR			0x0 	
ECCDR			0x0 	
	
SECBB2R1			0x0 	

PRIVBB2R1			0x0 	

SECWM2R_CUR			0x7 	
SECWM2R_PRG			0x0 	
WRP2R_CUR			0xff 	
WRP2R_PRG			0xff 	
EDATA2R_CUR			0x0 	
EDATA2R_PRG			0x0 	
HDP2R_CUR			0x1 	
HDP2R_PRG			0x1 	

 Also I realized there was another mistake in the code. I was not passing the pointer to the value to be written but the value itself, which I have fixed. 

But that has not resolved the hard fault.

See the updated code below:

static FLASH_EraseInitTypeDef EraseInitStruct;
uint32_t flash_sector_error;
EraseInitStruct.Banks = FLASH_BANK_1;
EraseInitStruct.TypeErase = FLASH_TYPEERASE_SECTORS;
EraseInitStruct.Sector        = 24;
EraseInitStruct.Banks     = FLASH_BANK_1;
EraseInitStruct.NbSectors     =1;
uint32_t data_to_be_written =43210;
if(HAL_FLASH_Unlock()==HAL_OK)
{
	SEND_STRING("FLASH UNLOCKED\r\n");
}
if (HAL_FLASHEx_Erase(&EraseInitStruct, &flash_sector_error) != HAL_OK){
	SEND_STRING("FLASH ERASE FAIL\r\n");
}
else
{
	SEND_STRING("FLASH ERASE OK\r\n");
}

//HARDFAULT OCCURS HERE |V|
if(HAL_FLASH_Program(FLASH_TYPEPROGRAM_WORD_EDATA, FLASH_ADDR, (uint32_t *)data_to_be_written) != HAL_OK){
	SEND_STRING("FLASH WRITE FAIL\r\n");
}
else
{
	SEND_STRING("FLASH WRITE OK\r\n");
}
HAL_FLASH_Lock();

Also for reference I am not using the ICACHE. 

[TG_APCD · Accepted solution]

I think I found the missing secret here.

I was missing the HAL_FLASH_OB_Launch(); call which sets the Option Start bit. 

//configure option bits
HAL_FLASHEx_OBProgram(&FLASH_OBInitStruct);
HAL_FLASH_OB_Launch(); //set the OPTSTART bit in OPTCR