STM32G070KB with RDP set to level 1 with J-Flash kills the device.

[Zed]

Hi!

Can someone explain to me why this code:

// Is FLASH_CR register locked for writing?
if (FLASH->CR & FLASH_CR_LOCK)
{
	// Unlocking FLASH_CR register
	FLASH->KEYR = KEY1;
	FLASH->KEYR = KEY2;
}
 
// Unlocking FLASH option register
if (FLASH->CR & FLASH_CR_OPTLOCK)
{
	FLASH->OPTKEYR = OPTKEY1;
	FLASH->OPTKEYR = OPTKEY2;
}   
 
// Setting RDP level to 1
FLASH->OPTR &= ~FLASH_OPTR_RDP;
FLASH->OPTR |= 0xBB;  // Any value except 0xAA and 0xCC
 
while (FLASH->SR & FLASH_SR_BSY1);
 
FLASH->CR |= FLASH_CR_OPTSTRT;
 
while (FLASH->SR & FLASH_SR_BSY1);
 
// Updating option bytes by resetting of the device
FLASH->CR |= FLASH_CR_OBL_LAUNCH;

kills STM32G070KB device, when was written with J-Flash, but works great with STM32G071CB with the same Errata note for RDP protection.

Same code works great for both MCUs when were written with Segger Embedded Studio.

PS: I'm also posting this question on Segger's forum.

Thank you!

[Uwe Bonnes]

What do you mean by "kill"? Does the "magic smoke" excape from the chip.

[MM..1]

Why you waste time AND MONEY when ST LINK exist and woirk..??

[Zed]

The device doesn't respond anymore.

[Zed]

It wasn't my decision, but until this moment everything was working great.

[vamsi]

I too had problem writing 0xBB, and lost few boards. This RDP level 1 doesn't seem to be working. This is on STM32G030C8

[MM..1]

Maybe you can try BOOT pin and system bootloader UART clear RDP back to normal...

[Tesla DeLorean]

Doesn't seem to be working, or locking out access for people to touch and access device internals?

Does the code running internally on the chip continue running? Did you implement a method to recover / mass-erase?

As MM indicates some of these devices need to be walked out of the protection modes via the ROM loader. Segger used to have specific recovery tools

[vamsi]

It works, but we want to deliver the products with RDP Level 1 to customer. Now I'm skeptical is this RDP Level 2 flawless?

[MM..1]

Why you mean no. When you change RDP back chip is erased = data is protected