The General USB Process
The Enumeration Process:What happens when a device is connected?
Software – General Concepts
//Sample Standard Device Descriptor Type
//Definition Fields
Length (18)
Descriptor Type (DEVICE, CONFIGURATION, INTERFACE, ENDPOINT, HID)
USB Spec Release Number (0200h)
Device class (hub type…Human Interface defined in other descriptor, CDC described here)
Device Sub-class (00h)
Device protocol (00h)
Maximum Packet size (64 bytes – max for the endpoint)
Vendor ID (ID assigned by USB IF)
Product ID (ID assigned by product manufacturer) Device release number (revision code of device) Manufacturer (ABC Corp)
Product (string identifier) Serial Number (1234)
Number of configurations (1 or more configurations can follow)
Host
TM
Here is your unique address. What device class are you?
What transfer mode do you want? Do you supply the power or do I?
How many and of what type of endpoints do you need?
