USB class 0xdc — Diagnostic
Class code 0xdc marks a device or interface as Diagnostic. Operating systems read this value from the descriptor and bind a generic class driver, which is why most diagnostic hardware works without a vendor driver even when the VID:PID pair is unrecognised.
How it appears on your system
$ lsusb -v
bInterfaceClass 220 DiagnosticWindows exposes the same value in the compatible IDs list as USB\Class_DC, extended with &SubClass_xx&Prot_xx for the subclass and protocol below.
Subclass and protocol codes
| Subclass | Protocol | Meaning |
|---|---|---|
| 01 | — | Reprogrammable Diagnostics |
| 01 | 01 | USB2 Compliance |
Looking up a specific device instead? Search by VID:PID or browse the vendor directory.