Beyond Logic

USB Protocol Analysers

With USB's differential bus and highly complex protocol, what do you do when you want to monitor what is going on between your device and the host? You can't just grab the digital storage oscilloscope and probe around like you could with less complex traditional serial buses. What you need is a USB Protocol Analyser.

Most developers are now thinking this must be expensive. Yes, many are. But at what cost do you value a days trial and error when you can't see exactly what is going on. Perhaps the tension is building between the software engineer and the firmware engineer, neither will admit the problem lies with their code.

While there are the more known players such as CATCs or Catalyst Enterprises, Ellisys had captured the market with the very functional and easy to use, "USB Tracker" supporting the analysis of low and full speeds. Just recently, they have built on the great success of the tracker with the Ellisys USB Explorer 200 which now supports high speed 480Mbps, yet still at an very affordable price.

    Ellisys USB Explorer 200
    • Supports Low Speed (1.5Mbits/s), Full Speed (12Mbits/s) and High Speed (480Mbps)
    • Measurement of USB bus states and low level protocols
    • Device Bus Powered. No need for external adaptor.
    • Speedy USB2.0 Uplink with Internal 32MB FIFO Memory.
    • Intutive, Easy to use Interface.
    • High level decoding of requests and descriptors, making diagnosing problems a breeze.
    • Filtering and Highlighting of Events.
    • Dimensions: 150 x 120 x 65 mm, Weight 850g.
    • 3,470 Swiss Francs (~$2600 USD) and includes a 2 years of limited warranty.
Ellisys USB Tracker 110 Highly Recommended
  • Supports Low Speed (1.5Mbits/s) and Full Speed (12Mbits/s)
  • Unlimited capture time.
  • USB2.0 Uplink (Backwards compatible with 1.1).
  • Device Bus Powered. No need for external adaptor.
  • Power and Activity LEDs. Activity flashes green on receipt of DATA0/1 packet but not captured and red if captured.
  • Realtime statistics during capture.
  • Filtering and Highlighing of Events.
  • Dimensions: 85 x 80 x 45 mm, Weight 75g.
  • 1,170 Swiss Francs (~$850 USD) and includes a 2 years of limited warranty.

The 1.2MB accompanying software installs like a treat and is quite intuitive to use. The events are stored in an expandable table which makes it easy to navigate hundreds and thousands of events, something that some competitors more graphical software solutions lacks. The details tab on the right by default only shows the more important and frequently used fields, helping cut down on cutler and information overload.

The software provides the normal filtering one would expect plus the option of "colouring" (in pascal colours off course) transactions via endpoints numbers. Any possible breaches of the specification comes up with a little yellow exclamation mark and the field in red. This quickly helps weed out possible problems with descriptors etc.

The Software is free which allows others in your organisation to display captured results. It comes with a couple of demonstration logs including a camera, memorystick and mouse captures. If you are in the market for an Analyser we recommend you take a minute to download the Ellisys USB show software and see just what it offers you. I don't believe you will be disappointed.

The USB tracker from Ellisys opens up these powerful tools to the smaller developers who were previously priced out of the market. While it doesn't do Inrush Current, or Signal Integrity, Skew, Jitters Measurements etc like the more pricey units it does provide a range of functionality which should help get your next project out to market quicker.

Another low cost USB Protocol Analyzer is the USB Viewer from USB

    USB's USB Viewer
    • Supports Low Speed (1.5Mbits/s) and Full Speed (12Mbits/s)
    • USB2.0 Uplink (Backwards compatible with 1.1).
    • Device Bus Powered. No need for external adaptor.
    • Power and Activity LEDs.
    • Ability to trigger on PIDs such as Setup, In, Out, Data0 etc.
    • Graphical Representation of Data.
    • 128kbyte FIFO Memory.
    • Download demo software to try before you buy here.
    • Buy Now. $950.00 USD

Once again the software is available for download so you can try it out before you buy. The shrink view allows the user to quickly determine the position of data in amongst SOF etc.

Copyright 2003-2005 Craig Peacock - 15th June 2005.