About ST-Link Connection Method

[Y.Yamashita]

I am using the NUCLEO-U575ZI-Q board.
In ST32CubeProgrammer, the option byte TZEN is enabled.
In this state, when I changed the readout protection level from Level 0 to Level 1, I was no longer able to connect via ST-Link.
Please tell me how to recover so that ST-Link connection becomes possible again.

[Frantz LEFRERE]

Dear ​@Y.Yamashita 

If TZEN is enabled and you are in RDP1, connection is only possible if the MCU is in non-secure state.
This is explain in the following video.

The solution is describe in this video :
If before moving in RDP1, you have a code in the target that run a secure /non secure application, a connect without reset will be possible
If not, please activate the embedded bootloader connecting the BOOT0 pin to VDD.
Br,

Frantz 

[Y.Yamashita]

Dear Frantz-san,  

Thank you for your reply and comments.
I resolved this issue by activating the embedded bootloader and connecting the BOOT0 pin to VDD.  

Best regards,
Y.Yamashita