STM32U575 chip short when JTAG Connected

[southernGB]

Hi all

I am trying to program an STM32U575RIT6 chip using a TAG connect and ST link V3, on plugging in the tag connect, the chip shorts and becomes unrecoverable. I make sure to ground the linker before inserting, doing it all on a grounded matt, with the power to the board off before plugging it in.

This seems to happen at random, as sometimes the programming will work and program fine, other times it shorts. I replace it with a new chip and it works for a while and then shorts again. When the chip is programmed, it works fine and as expected, until the point I come to reprogram it and it shorts.

I've tried other ST links, and cables, to verify its not just my linker and still get the same results. I've tried keeping the board powered on when I plug the STM link in, and still get the issue.

I've moved from using an STM32L452 and STM32L496 which I never had any problems with programming, only ever this U5 chip.

Any advice on what I am doing wrong, or how to stop this from happening.

I've added the schematic diagram for the ST link to my chip for reference.

Thanks in advance :)

[Sarra.S]

Hello @southernGB, 

The 10µF capacitor (C71) on the SWD lines might be causing issues, try reducing the capacitance or removing it temporarily to see if the issue persists? 

[southernGB]

Hi @Sarra.S ,

I've tried this method and the STM32U5 has still shorted out when the ST link is connected.

[Tesla DeLorean]

Then you'll need to review the connector, and what it connects too. Make sure you've not mirrored or confused the pin designations.

This isn't a standard 10/20-pin JTAG as exported by the ST-LINK's

Review your netlist. Review all pin assignments.

Review part orientation.

Check analogue supply.

Check voltage on VCAP pin

[Tesla DeLorean]

PC13 probably isn't suitable for driving things, it's typically in a low-power domain

Do not put an operating board on a conductive surface or foam.

Check unpopulated board vs net-list.