STM32CubeProgrammer cannot connect to board using ST-LINK V3

[SedCore]

Hi, I get the below error when trying to connect to my B-U585I-IOT02A board in "Hot plug" and "Hardware reset" modes, whatever is the frequency. I get the same error even with BOOT0 High.

I'm using STM32Cube Programmer v2.17.0

Connection is successful only when I keep on pressing the reset button, but there is no option byte set and any attempt to set option bytes fails.

Thanks in advance for your support.

[AScha.3]

Hi,

try with these settings:

SWD...software reset, debug in low power mode..

[SedCore]

Still this error:

 

[AScha.3]

Hmmm...

Was it working before ?

Did you set some protection or debug authent. ?

Power consumption ...normal ? Gets something hot ?

[SedCore]

Whether BOOT0 is high or low, the behavior is the same, I have to keep the reset button pressed down.

Could it be that the STM32U5 is continuously resetting?

[TDK]

That's a strong possibility. Here are other things that would cause what you're seeing:

• Chip constantly resetting (NRST going low).
• Chip performs FLASH operation immediately on startup.
• Chip goes into low-power mode.
• Chip re-initializes the SWD pins.

Booting into the bootloader will prevent any of these from happening, but of course you need a way to actually do that.

[SedCore]

Ok, I see. But yet the problem is about being able to boot into the bootloader. I don't have idea on how to do so.