FAQ: Possible communication failure between STLINK-V3 and some recent computers

[FBL]

While the STLINK-V3 is compliant with USB 2.0 and exhibits reliable USB performance across various platforms since several years, the USB communication may fail between an STLINK-V3 and some recent computers. 

1. Root cause

The root cause comes from the interoperability issues of a eUSB2 to USB 2.0 High-Speed repeater used on certain recent computers. This repeater doesn’t respect the original USB2 specification. As of September 2024, USB-IF has published a new release of the Embedded USB2 (eUSB2) Physical Layer Supplement to the USB Revision 2.0 Specification (Rev.1.2) on their website. This release now includes a new ECN entitled “Repeater HS SYNC Forward”, addressing the interoperability aspect for future devices.

2. Mitigation

To mitigate potential USB communication failures between your host computer and your STLINK-V3 device (this applies to standalone STLINK-V3SET, STLINK-V3MINIE, STLINK-V3MODS probes, and to embedded STLINK-V3 on Nucleo boards and Discovery kits), we suggest the following tested workarounds:

1. Try to connect to another USB Type-C® port on your computer if available. Alternatively, using a USB Type-A port of your computer usually solves the issue.
2. Connect the STLINK-V3 via an external USB High-Speed hub to the USB Type-C® port of your host computer (tested hub reference: Anker332 5in1).
3. Use a different standalone probe to connect to your target board: ST-LINK/V2, STLINK-V3PWR, Segger J-Link.

Our team is actively exploring additional solutions to this issue. We apologize for any inconvenience this may cause, and we appreciate your understanding as we work to resolve this matter.

[Andrew Neil]

In affected cases, would the ST-Link show up in Windows Device Manager (or equivalent on other systems)?

Ref: https://community.st.com/t5/stm32-mcus/how-to-solve-debugger-connection-issues/tac-p/698105/highlight/true#M956

[MKori.1]

Is the issue with the missing full-speed implementation resolved? Previous it wasn't possible to connect a STLink-V3 via an USB-2 Full-Speed (not High-Speed) Isolator as the driver interface implementation was just an empty shell.

Please also see:
https://community.st.com/t5/stm32-mcus-boards-and-hardware/failed-to-connect-to-stlink-v3-using-a-usb-isolator/m-p/273483/highlight/true#M9452

[davetoaster]

This issue also affects any product that uses the STM32F7 for USB 2.0 HS with the built-in PHY (not just STLINK probes).

That means that the STM32F7's USB HS peripheral simply doesn't work with recent Apple Macs. Would love to hear if there's a workaround for this!

[FBL]

Hi @davetoaster 

Unfortunately, no software workaround for that interoperability issue with the eUSB repeaters on F7 family.

[Parawizard]

@davetoaster What I am seeing is that there is some intermittent enumeration on Apple Silicon. M4 Mini back ports are very bad. The front ports are on a hub that works fine though. Laptops you have less choice.