The AU-UB7320 USB 2.0 Device AMBA Subsystem provides a USB 2.0 Device peripheral
subsystem for AMBA based SOCs. It contains a USB 2.0 Device that connects seamlessly to the
AMBA AHB Bus. It includes the required USB endpoints plus eight bulk/iso transfer endpoints.
A DMA Engine is included to move bulk and isochronous USB data. The figure below shows its
use within an SOC. The USB 2.0 Device AMBA Subsystem Core is available as a synthesizable
Verilog model from Aurora VLSI, Inc.

USB 2.0 Device
• Ten endpoints:
- EP0- control endpoint, accepts SETUP, IN, and OUT control transactions
- EP1- interrupt endpoint, accepts IN and OUT interrupt transactions
- EP2, EP4, EP6, EP8- IN endpoints; accept IN bulk and isochronous
transactions
- EP3, EP5, EP7, EP9- OUT endpoints; accept OUT bulk and isochronous
transactions
• Includes control pipe registers and USB Descriptor RAMs at EP0
• USB command execution in EP0
• 8 or 16 bit UTMI interface
• Accepts stalls from the application logic
DMA/AMBA Interface
• AMBA AHB Bus interface
• 10 channel DMA Engine
- bulk/iso IN data from each bulk, iso, and interrupt IN endpoint to the USB 2.0
Device block
- bulk/iso OUT data from the USB 2.0 Device block to each bulk, iso, and
interrupt OUT endpoint
• Physical DMA addresses
• Programmable DMA starting address
• Programmable DMA transfer count- up to 64 Kbytes
• Programmable DMA AMBA Bus interface transaction size- 8 to 1024 bytes
• Programmable DMA AMBA Bus data transfer size- 4 or 8 bytes
• Locked DMA operation optional (software programmable)
• Direct software writes or information extracted from descriptors in memory, to
program DMA control information
• 2 AMBA Bus master interfaces- one for IN data, one for OUT data
• AMBA Bus slave interface for register reads and writes
• Interrupts:
- DMA completed
- IN transaction data sent
- OUT transaction data received