Understanding USB Controllers¶

How USB controller roles, host/device modes, and the Linux stack fit together.

This English edition retains the original diagrams and practical code or command examples.

Commands and examples¶

This article is a conceptual reference; review the hardware documentation for platform-specific details.

Practical notes¶

Validate pin multiplexing, clocks, power sequencing, kernel configuration, and device-tree bindings on the target board before drawing conclusions from a test result.