Freescale Semiconductor ColdFire MCF52210 - Manual (Page 230)

Universal Serial Bus, OTG Capable Controller
MCF52211 ColdFire® Integrated Microcontroller Reference Manual, Rev. 2
15-2 Freescale Semiconductor
USB software provides a uniform view of the system for all application software, hiding implementation
details making application software more portable. It manages the dynamic attach and detach of
peripherals.
There is only one host in any USB system. The USB interface to the host computer system is referred to
as the Host Controller.
There may be multiple USB devices in any system such as joysticks, speakers, printers, etc. USB devices
present a standard USB interface in terms of comprehension, response, and standard capability.
The host initiates transactions to specific peripherals, while the device responds to control transactions.
The device sends and receives data to and from the host using a standard USB data format. USB 2.0
full-speed /low-speed peripherals operate at 12Mb/s or 1.5 MB/s.
For additional information, refer to the USB2.0 specification [2] .
Figure 15-1. Example USB 2.0 System Configuration
Host
Software
USB Cable
USB Cable
USB Cables
Host PC
External Hub
USB Cable
External Hub
USB Peripherals
Root
Hub