Information

Universal Serial Bus Interface
MPC8308 PowerQUICC II Pro Processor Reference Manual, Rev. 1
13-2 Freescale Semiconductor
13.1.1 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 UTMI low pin count interface (ULPI) transceivers
(PHYs). An external PHY would be used to interface to ULPI.
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.
13.1.2 Features
The USB DR module includes the following features:
• Complies with USB specification rev 2.0
• Supports operation as a standalone USB host controller
— Supports enhanced host controller interface (EHCI)
• Supports high-speed (480 Mbps), full-speed (12 Mbps), and low-speed (1.5 Mbps) operation. Low
speed is only supported in host mode.
• Supports external PHY with ULPI (UTMI + low-pin interface)
• Supports operation as a standalone USB device
— Supports one upstream facing port
— Supports three programmable, bidirectional USB endpoints
• Host and device support
• OTG (on-the-go) support, which includes both device and host capability, with external PHY
(ULPI)
13.1.3 Modes of Operation
The USB DR module has three basic operating modes: host, device, and OTG.
NOTE
Only high-speed and full-speed operations are supported in device mode.