F072 user data option bytes

[tje7415]

ive been trying to use the two option bytes available for the user. but i have not been able to get it to Write to them i code. 

editing the bytes via cubeProgrmmer then reading them with the following:

uint8_t userByte0 = HAL_FLASHEx_OBGetUserData(OB_DATA_ADDRESS_DATA0);
uint8_t userByte1 = HAL_FLASHEx_OBGetUserData(OB_DATA_ADDRESS_DATA1);

That works as expected. But trying to write to them does not work. 

	FLASH_OBProgramInitTypeDef obConfig;

	HAL_FLASHEx_OBGetConfig(&obConfig);

	obConfig.OptionType = OPTIONBYTE_USER;  // Specify we are modifying user option bytes
	obConfig.USERType = OB_USER_DATA0;      // Select User Data Byte 0
	obConfig.USERConfig = 0x55;             // Set the value (change as needed)
	HAL_FLASH_Unlock();
	HAL_FLASH_OB_Unlock();
	HAL_FLASHEx_OBProgram(&obConfig);
	HAL_FLASH_OB_Launch();

I tired to check the bytes via cubeProgrammer but does not seem to be present.

[Amel NASRI]

Hi @tje7415 ,

2 recommendations:

• Verify that HAL_FLASHEx_OBProgram returns HAL_OK to ensure that the programming operation was successful.
• Ensure that the Flash and Option Bytes are locked at the end: 

HAL_FLASH_OB_Lock();
HAL_FLASH_Lock();

-Amel