Concepts
The General USB Process
How Does the Host Know a Device’s Requirements?
When a USB device is plugged into a USB port the host communicates with the device and configures each device according its unique requirements such as:
1.Type of transfer required (interrupt, bulk, isochronous, or control
2.Who supplies the power (host or device)
General
3. Maximum packet size
TM
Software –
4. The number of configurations (e.g., a single device can be configured to use its own power or power from the host)
5. Manufacturer’s product ID and registration information
6. Etc.
This configuration process is called enumeration. Enumeration is be covered in greater detail later in this presentation
