Can't program/connect STM32WL55CC unless Hot Plug, why?

[LEdou.1]

Hi,

I have new custom board on STM32WL55CCU7. I can't flash/program with STM32CubeIDE.

And when i try to connect with STM32CubeProgrammer with "Normal'" mode I have this error :

"Error: Cannot connect to access port 1! If you are trying to connect to a device with TrsutZone enabled please try to connect with HotPlug Mode"

 14:23:09 : ST-LINK SN : 002900213431511631343632

 14:23:09 : ST-LINK FW : V3J10M3

 14:23:09 : Board      : STLINK-V3MINIE

 14:23:09 : Voltage    : 1,78V

 14:23:09 : Error: Cannot connect to access port 1! If you are trying to connect to a device with TrustZone enabled please try to connect with HotPlug mode.

And if i try to connect with "Hot Plug" mode I have this :

 14:19:28 : ST-LINK SN : 002900213431511631343632

 14:19:28 : ST-LINK FW : V3J10M3

 14:19:28 : Board      : STLINK-V3MINIE

 14:19:28 : Voltage    : 1,79V

 14:19:28 : SWD freq   : 1000 KHz

 14:19:28 : Connect mode: Hot Plug

 14:19:28 : Reset mode : Hardware reset

 14:19:28 : Device ID  : 0x497

 14:19:28 : Revision ID : Rev Y

 14:19:28 : UPLOADING OPTION BYTES DATA ...

 14:19:28 :  Bank         : 0x00

 14:19:28 :  Address      : 0x58004020

 14:19:28 :  Size         : 96 Bytes

 14:19:28 :  Bank         : 0x01

 14:19:28 :  Address      : 0x58004080

 14:19:28 :  Size         : 8 Bytes

 14:19:28 : UPLOADING ...

 14:19:28 :  Size         : 1024 Bytes

 14:19:28 :  Address      : 0x8000000

 14:19:28 : Read progress:

 14:19:28 : Data read successfully

But I can't do a Mass erase, i have this error :

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

Any idea why please ?

[Bubbles]

Hi @LEdou.1​,

seeing the OB values would help with accurate reply. STM32WL is dual core, with some aspects of the TrustZone features (not really TrustZone, but quite a lot in common). In this sense, the M4 core is regarded as non-secure and the M0+ core is the "secure". If the product is configured for secure boot with M0+ core, it's impossible to connect normally, only hot-plug. Then the M0+ security protection will also prevent mass erase.

But you may still attempt regression to wipe the MCU.

BR,

J

[LEdou.1]

Ok thanks !

Here this what I have on OB Menu. RDP is set to 00, on SDK we have AA.

If i try to change to AA, STM32CubeProgrammer get stuck and crash on Linux (version v2.12.0) and STLIN-V3MINIE (version V3J10M3 STM32 Debug + VCP)

I have never program it, and all my board are in this state.

[Bubbles]

Hi @LEdou.1​,

the OB don't look healthy. It looks like the tools read all zeroes, which is not a default state and not even a valid state.

You are correctly trying to get the RDP to 0xAA value, this should normally trigger the regression and put the product to RDP0. Reading 0 in the RDP OB should be interpreted as RDP level 1, which should allow regression. I'm not aware of any exception.

I never encountered a situation where the STM32CubeProgrammer would crash, so this is really unknown territory for me. In your place it'd probably try using alternative tools. For example STlink v2, Windows machine, even the legacy ST-link Utility, the predecessor of STM32CubeProgrammer should support STM32WL (but probably not stlink v3).

Then there is possibility that you received defective or even counterfeit parts.

BR,

J

[LEdou.1 · Accepted solution]

I found the error/solution. It seem that our ESD diode on NRST was on the wrong side !

That why Hot plug, was the only one responding, and CubeProgrammer waiting for reset/read bit.

Thanks for your help @JHOUD