I am testing the boot mode of STM32G070 with Nucleo-G070RB board, using an IAR I-iet emulator. Thanks.

[CChen.16]

I try to use UART to download firmware to the board with STM32CubeProgrammer, UART 1 was connected to the PC. 

I added the following code trying to set the MCU to boot mode, but after run this code, my I-jet emulator stop working, cannot talk to the CPU any more. Now nothing works with the board, my questions are:

1. How can I recover? 

2. Is there any other way to check the status of the MCU? 

void set_to_boot_mode(void)

{

 FLASH_OBProgramInitTypeDef OBInit;

 uint32_t config = 0;

 /* Unlock tha User Flash area */

 HAL_FLASH_Unlock();

 HAL_FLASH_OB_Unlock();

 /* Get the Dual boot configuration status */

 HAL_FLASHEx_OBGetConfig(&OBInit);

 config = OBInit.USERConfig;

 OBInit.USERConfig = OB_BOOT0_FROM_OB | OB_BOOT1_SYSTEM | OB_nBOOT0_SET;

 HAL_FLASHEx_OBProgram(&OBInit);

 HAL_FLASH_OB_Launch();

 // reset

 HAL_NVIC_SystemReset();

}

[JVerv.948]

Hi, I appear to have done the same mistake you have. On my STM32G031 Nucleo-32 I configured the MCU to use the external Boot0 pin but now it does not appear to boot at all. It is no longer recognized by the onboard ST-Link and no matter if I set Boot0 to High or Low it does not appear to be running. Did you ever determine what you issue was and, if so, how to fix it?

[Antoine Odonne]

​Hello,

I am afraid that you don't keep the config of previsouly programmed user options.

And would then rewrite them with 0 in your sequence. (Leading to setup of RAM parity check and Hardware watchdog starting)

Using CubeProgrammer or ST-Link Utility you should be able to connect to target under reset, and modify those OB afterward back to default values.