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B-U585-IOT-2A Flash Write Protection

PJose.4
Senior

Hi @ community
I am working around the flash lock protection that was somehow enabled in my development board(B-U585-IOT2A) while testing the TF-M SBSFU Application and now i am unable to do a flash erase on my chip. The cube programmer is showing the following error message while doing a full chip erase:

PJose4_0-1688387786716.png

As per the inputs received(referred from st tutorial video),  I have tried the following sequences to deactivate the TF-M with no valid secure code:
1. Boot from RSS(Boot 0 pin connected to VDD).
2. Power on Reset.
3. Separate power given to the development board(usb c supply with change in jumper position JP4) in addition to ST Link supply.
4. Connected to Cube Programmer in Hot plug and SWD mode.
5. Enabled the TZEN bit and did power reset.
6. Changed the RDP Level to DC and did power on reset.
7. Changed RDP from DC to level AA and TZEN=0 at the same time.
8. after power on reset checked the chip erase functionality. it is returning the same error message.

I checked the option bytes WRP1A, WRP1B and WRP2A WRP2B. it is showing as unlocked as shown in the figure:

PJose4_1-1688388102857.pngPJose4_2-1688388129681.png

I am unable to understand the issue. i am stuck here and want to test some programs and due to the flash lock i am unable to proceed any further. I request urgent attention in this regard so as to move any proceed. Please let me know if any other methods that i have to follow so as to unlock the secure set of the memory. 
One more doubt - when execution of TF-M is the secure memory lock being applied to the controller(that means any sort of WRP - write protections).
Thanks for the support in advance.
PJose

 

1 REPLY 1
Jocelyn RICARD
ST Employee

Hello @PJose.4,

As you could see, I already answered in other thread:

https://community.st.com/t5/security-mcu/reverting-option-byte-configuration-after-tf-m-testing-in/m-p/571049#M5817

Again sorry for late answer

Best regards

Jocelyn