Freescale Semiconductor TWR-MCF52259-Ethenet - Manual (Page 104)

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The General USB Process
1. Enumeration -Upon powering up, the host: queries all connected devices
to determine the requirements of each (such as, class of device power
source, number and types of endpoints) and assigns a unique address for
each. This same process occurs for devices that are dynamically “plugged
in” to the host except the host waits ~120ms for the device to settle.
The Enumeration Process:
What happens when a device is connected?
Host
What device class are you?
Do you supply the power or do I?
How many and of what type of
endpoints do you need?
Here is your unique address.
What transfer mode do you want?