Freescale Semiconductor ColdFire MCF52210 - Manual (Page 229)

MCF52211 ColdFire® Integrated Microcontroller Reference Manual, Rev. 2
Freescale Semiconductor 15-1
Chapter 15
Universal Serial Bus, OTG Capable Controller
NOTE
Portions of Chapter 15, “Universal Serial Bus, OTG Capable Controller,”
relating to the EHCI specification are Copyright © Intel Corporation
1999-2001. The EHCI specification is provided “As Is” with no warranties
whatsoever, including any warranty of merchantability, non-infringement,
fitness for any particular purpose, or any warranty otherwise arising out of
any proposal, specification or sample. Intel disclaims all liability, including
liability for infringement of any proprietary rights, relating to use of
information in the EHCI specification. Intel may make changes to the EHCI
specifications at any time, without notice.
This chapter describes the USB Dual Mode FS/LS Host - FS Device Controller and Universal Serial Bus
(USB) interface, which implements many industry standards. However, it is beyond the scope of this
document to document the intricacies of these standards. Instead, it is left to the reader to refer to the
governing specifications.
The following documents are available from the USB Implementers Forum web page at
http://www.usb.org/developers/docs :
• Universal Serial Bus Specification, Revision 1.1
• On-The-Go Supplement to the USB 2.0 Specification, Revision 1.0a
15.1 Introduction
This section describes the USB Dual-Mode (DM) controller. The OTG implementation in this module
provides limited host functionality as well as device FS solutions for implementing a USB 2.0
full-speed/low-speed compliant peripheral. The OTG implementation supports the On-The-Go (OTG)
addendum to the USB 2.0 Specification. Only one protocol can be active at any time. A negotiation
protocol must be used to switch to a USB host functionality from a USB device. This is known as the
Master Negotiation Protocol (MNP).
15.1.1 USB
The USB is a cable bus that supports data exchange between a host computer and a wide range of
simultaneously accessible peripherals. The attached peripherals share USB bandwidth through a
host-scheduled, token-based protocol. The bus allows peripherals to be attached, configured, used, and
detached while the host and other peripherals are in operation.