problem while programming Option Bytes to configure brown out

[DAUSILI]

Hi,

after I try to program option byte to configure brown out I can't  anymore reach the micro.

I'm working with a STM32G071KBU3.

I also try to connect to the micro using CUBE programmer. I get the error "target not found". Below my code.

The instruction that cause the fault was HAL_FLASH_OB_Launch();

How can I get my micro out of this fault? Which is the error on the code below.

Thankyou

 

static void BrownOut_Init(void)

{

 

FLASH_OBInitStruct.WRPArea = OB_WRPAREA_ZONE_A;

 

HAL_FLASHEx_OBGetConfig(&FLASH_OBInitStruct);

 

// unlock FLASH control register access

HAL_FLASH_Unlock();

// unlock FLASH Option Bytes Registers access

HAL_FLASH_OB_Unlock();

 

FLASH_OBInitStruct.OptionType = OPTIONBYTE_USER;

FLASH_OBInitStruct.USERType = OB_USER_BOR_EN | OB_USER_BOR_LEV;

FLASH_OBInitStruct.USERConfig = OB_BOR_ENABLE | OB_BOR_LEVEL_FALLING_0 | OB_BOR_LEVEL_RISING_0;

 

HAL_FLASHEx_OBProgram(&FLASH_OBInitStruct);

 

/* Launch the option byte loading */

HAL_FLASH_OB_Launch();

 

// lock del FLASH Option Bytes Registers access

HAL_FLASH_OB_Lock();

// lock del FLASH control register access

HAL_FLASH_Lock();

}

[Diane POMABIA]

Hello @DAUSILI 

What was state of BOOT_LOCK before trying to programm your OB?

Regards

Diane

[DAUSILI]

Hi Diane,

the Flash memory address: 0x1FFF 7870 where is located BOOT_LOCK was 0x0000 0000 (as ST production value).
thank you for your support.

[DAUSILI]

Hi,

any other suggestions please?

Reading in other forum thread about this topic someone suggest to use ST-link Utility tool to reload the option bytes to their default value. But also with this tool I can't reach the micro.

Despite this my main problem now is to have a BOR config procedure working.
In my application I haven't an extern reset circuit.
what could I have done wrong on my code?
Regards.