Information

Chapter 40
Universal Serial Bus OTG Controller (USBOTG)
40.1 Introduction
NOTE
For the chip-specific implementation details of this module's
instances see the chip configuration chapter.
This section describes the USB. The OTG implementation in this module provides
limited host functionality and device 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).
40.1.1 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.
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.
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
Freescale Semiconductor, Inc. 883