Freescale Semiconductor MPC8313E PowerQUICC II Pro Family Reference Manual page 930

Universal Serial Bus Interface
16.1 Introduction
The device implements a a dual-role (DR) USB module. This module may be connected to an external
port. Collectively the module and external port are called the USB interface. The USB interface is shown
in Figure 16-1.
16.1.1 Overview
The USB DR module is a USB 2.0-compliant serial interface engine for implementing a USB interface.
The registers and data structures for the module are based on the Enhanced Host Controller Interface
Specification for Universal Serial Bus (EHCI) from Intel Corporation. The DR module can act as a device
or host controller. Interfaces to negotiate the host or device role on the bus in compliance with the
On-The-Go (OTG) supplement to the USB specification are also provided.
The DR module supports the required signaling for USB transceiver macrocell interface (UTMI) and
UTMI low pin count interface (ULPI) transceivers (PHYs). The PHY interfacing to the ULPI is an external
PHY.
The module contains a chaining DMA (direct memory access) engine that reduces the interrupt load on
the application processor and reduces the total system bus bandwidth that must be dedicated to servicing
the USB interface requirements.
16.1.2 Features
The USB DR module includes the following features:
• Complies with USB specification rev 2.0
• Supports operation as a standalone USB host controller
MPC8313E PowerQUICC™ II Pro Integrated Processor Family Reference Manual, Rev. 2
16-2
Dual-Role
Module
(DR)
Figure 16-1. USB Interface Block Diagram
CSB
TX Buffer
RX Buffer
On-Chip PHY
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