1. USB host for web camera connection
High Speed Digital Systems Lab
USB host for web camera connection
Final presentation – Part A
Presenters:
Alexander Shapiro
Sergey Alexandrov
Supervisor:
Mike Sumszyk

2. Agenda Part B project objectives Demo Project objectives.
System architecture.
Project flow.
USB basics.
ISP 1362.
Isochronous transfer.
YUV video.
Part B project objectives
Demo

3. Project Objectives Implementation of SOPC interface for USB webcam.
Learn and implement USB host protocol.
Learn and implement webcam protocol.
Learn SOPC Development tools.
Understand NIOS II architecture.
Building NIOS II softcore system.
Receive picture from the webcam.
Convert YUV to RGB and display in Matlab

4. Development Environment
Altera DE2 board
Provides USB support for host and device application.
VGA output (up to1600 x 1200 at 100-Hz refresh rate).
Cyclone II FPGA
Programmable chip to implement any design.
Programming tools:
Quartus II, Nios II IDE, SOPC Builder
Debug tools:
Hardware and software USB analyzer.

5. System Architecture Input Output USB Philips ISP1362 controller.
Transfer rate: 12 Mb/s.
Output
Change the System architecture diagram
VGA DAC (10-bit triple DACs).
Up to 1600x1200 at 100-Hz.

6. Logic Flow diagram

7. Project Flow

8. Learn stage Working environment USB and ISP1362 documentation
SOPC builder
NIOS II
USB and ISP1362 documentation
Take mouse demo as basis for USB system.

9. Host implementation Initialize connection and open communication port.
Determine the kind of device.
Request configuration descriptor.
Learn basic device capabilities.

10. Webcam interface implementation
Probe and commit sequence.
Negotiation between Host and Video streaming interface.
Consists of Host`s requests with supported streaming parameters (bit rate, resolution) and Client`s confirmation/denial
Select video interface.
Device is configured and ready to work.

11. Webcam interface implementation
Probe & Commit flow
Host and device negotiate acceptable configuration.
It may take several iterations to “agree”

12. Mid-project milestone
Working webcam interface on NIOS II system
Initialization
Configuration
Bulk data transfer
No isochronous traffic support

13. ISO transfer over Philips ISP1362
Isochronous transfer is the most challenging aspect of the USB protocol.
Main issue – absence of code examples.
Almost no help could be obtained from forums and documentation.
No guidelines for implementation in Programming Guide.
Was implemented from scratch.
USB analyzer was irreplaceable in understanding and debugging.

14. ISO transfer over USB Host periodically sends ISO IN requests.
Device responds with ISO packets.
Each packet consists of payload and data.
Header holds error checks and End Of Frame indicators.
DATA is video stream in YUV2

15. Isochronous transfer buffering
Challenge:
Data to be delivered and processed each mSec.
CPU on embedded system cannot handle data each mSec.
Solution: ISP 1362 supports double buffering for ISO transfer
One buffer is proceeded while the second is filled.
1024 bytes in each buffer.
Toggle rate is configurable.

16. Debug tools: USB analyzer
USB HW analyzer is irreplaceable in debug.
Shows real traffic between host and device
Triggers on defined events
Clear log of USB packets
Showed what packets Windows sends to USB device. Software analyzer can show only driver level packets.
Helped find source of bugs.
Made it possible to ensure that host/device behaves according to our expectation.

17. Decode YUY2 video format
2 RGB pixels are defined in each macropixel (four bytes).
They share U and V components.
Natural bitrate is 2 bytes/pixel
Demands efficient real-time decoder to RGB

18. Part B Project Objectives
USB 1.1 Video implementation.
Integrate VGA controller.
Implement real-time video streaming
USB 2 support.
Migration to DE-3 environment.
Code optimization.
DMA
Hardware YUV to RGB decoder
USB 2 Video streaming to monitor

19. Demo

20. References Philips Embedded Programming guide
Philips ISP 1362 Data Sheet
USB 2.0 Specification
USB Video Class Specification
USB Complete by Jan Axelson
Google

21. End