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Senior II
September 21, 2025
Solved

Has ChatGPT bricked my NUCLEO-L433RC-P board :(

  • September 21, 2025
  • 2 replies
  • 1338 views

I wanted to do a full chip erase using STM32Programmer (I am trying to debug a custom bootloader) but kept getting the error "Mass erase operation failed.  Please verify flash protection".

I sent the following option byte screenshot to ChatGPT....

freeflyer_3-1758476281788.png

ChatGPT said...

 

Problem: PCROP Protection

In your PCROP Protection section:

  • PCROP1_STRT = 0xFFFF

  • PCROP1_END = 0x0000

  • PCROP_RDP is enabled

This is an invalid PCROP range: start at 0xFFFF, end at 0x0.
That effectively protects a huge chunk of flash against erase/program.

So even though WRP and RDP are fine, PCROP is blocking your erase.


Fix

  1. In STM32CubeProgrammer → Option Bytes → PCROP:

    • Set PCROP1_STRT = 0xFF

    • Set PCROP1_END = 0xFF

    • Uncheck PCROP_RDP unless you specifically need PCROP linked to readout protection.

  2. Apply changes (Program Option Bytes → Reset).

  3. Retry Full Chip Erase with ST-Link.

 
 

I did the suggested fix but it obviously didnt work.

But worse still, I cant even change the option bytes back to as they were because I get the following error....

18:45:49 : UPLOADING OPTION BYTES DATA ...
18:45:49 : Bank : 0x00
18:45:49 : Address : 0x40022020
18:45:49 : Size : 20 Bytes
18:45:49 : OPTION BYTE PROGRAMMING VERIFICATION:
18:45:49 : Error: Expected value for Option Byte "PCROP1_END": 0x0, found: 0xFF
18:45:49 : Error: Expected value for Option Byte "PCROP1_STRT": 0xFFFF, found: 0xFF
18:45:49 : Error: Option Byte Programming failed Or modified by application after OB_LAUNCH

I cant program or debug in STMCubeIDE either so Im worried my board is bricked.

Is it recoverable and if so how ?

Best answer by AScha.3

Before you give up - maybe last action:  to reset the pcrop...whatever its now....

AScha3_0-1758655426514.png

 

So try set : Uncheck PCROP_RDP + set RDP to level1 (protected) , 01  (or whatever, but NOT 0xCC !);

then restart/ power cycle and set Uncheck PCROP_RDP + RDP to 0xAA , to do regression;

AScha3_1-1758655692752.png

then apply....

AScha3_2-1758655825697.png

 

restart/ power cycle....and we know.

 

+

btw

The AI should know , how its done and not tell silly stories, except ...AI =Artificial I.d.i.o.t.

2 replies

MNapi
Senior II
September 21, 2025

connect your boot PIN to VCC then power your board, now you should be able to erase the chip.

freeflyerAuthor
Senior II
September 21, 2025

I connected BOOT0 pin to +3.3V and did a reset.

Then connected to STM32Programmer via STLINK and tried a full chip erase, but still got the same error "Mass erase operation failed. Please verify flash protection".

I also tried a power reset but the result is the same

MNapi
Senior II
September 21, 2025

I have no idea what you actually did.

You keep the PIN to VCC and keep connected when powering up and connect STM32programmr.

You do not do any reset power down or whatever you did and then connect STM32 programmer.

 

  • BOOT0 = 0 (Low): Normal operation, code execution from Flash memory.

  • BOOT0 = 1 (High): Enter bootloader mode for firmware update or debugging.

 

 

 

MNapi
Senior II
September 22, 2025

click on the icon OB you might have write protection active

freeflyerAuthor
Senior II
September 22, 2025

Write protection is set to level 0 (0xAA) as shown in the OB in the screenshot in the original post

MNapi
Senior II
September 22, 2025

SPRMOD is enabled uncheck and click apply