For STM32C562RE, why can CubeProgrammer validate the OEM key and report "RDP2 unlocked successfully", while does not erase existing user flash?

[Vishalpandey]

For STM32C562RE, why can CubeProgrammer validate the OEM key and report "RDP2 unlocked successfully", while the RDP regression does not erase the existing user flash and flash erase remains prohibited? Is this a known CubeProgrammer/ST-LINK limitation or does this indicate that the device was provisioned with a non-regressible security configuration?

Device: STM32C562RETx / NUCLEO-C562RE
CubeProgrammer: v2.22.0
ST-LINK: V3J17M11

SWD connection works.
Device ID: 0x44E.

OEM key is available.

RDP unlock operation sometimes reports:
"Validation Status: 3"
followed by:
"RDP2 unlocked successfully"

After physical power removal and restoration:

RDP_level = 0xFF (Unknown Value)

Flash still contains:
0x08000000 : 200007C8 08000671 0800073D 08000735

Mass erase:
Error: Mass erase operation failed. Please verify flash protection

Programming:
Erasing internal memory sector 0
Error: failed to erase memory

[Amine_Jridi]

Hello ​@Vishalpandey,

I am not able to reproduce the issue using STM32C562RE. Could you send you options bytes configuration ?

Also, I recommend switching to the latest version of STM32CubeProgrammer v2.23.

Thanks,

Amine.

[Vishalpandey]

Hi ​@Amine_Jridi 
Yeah sure, I am attaching a SS of option bytes of that board

and first, I was at the latest version v2.23.0 but I was not able to connect with ST-Link and the error was can not identify the device. I am attaching the SS of that also in 184225.png
So, if anything with latest info, just help me out!

Thanks & Regards!

[Amine_Jridi]

Hello ​@Vishalpandey,

The only difference I can observe is that you are using an old cut chip with no bootloader version (0xFFF), and that can explain the error in v2.23. Could you try with a new chip?

Thnaks,

Amine.

[Vishalpandey]

OK ​@Amine_Jridi,

I will try with the new chip!

Thanks & Regards
Vishal