October 11, 20001

2 Getting the Most Out of Your USB Bus/Protocol Analyzer Michael Pasumansky CATC

October 11, Why Do You Need a Bus/Protocol Analyzer? w You need an analyzer mostly to save time – Time to learn the technology – Development time – Debugging and testing time w From our experience – 9 different USB products developed in CATC during the past 5 years – All developments required using an analyzer – At least half of the products wouldn’t be on the market on time if we didn’t have a USB analyzer

October 11, And What Is on the Wire USB Implementation Areas w USB specification defines the 3 layers – Bus Interface Layer – Device Layer – Function Layer w Maps to the 3 protocol layers – Packets – Transactions (SETUP, IN, OUT) – Transfers (Control, Interrupt, Bulk, ISO) w Your analyzer has to be able to present the layers

October 11, What Would You Do With Your Analyzer? w Three major tasks related to bus traffic – Capture – View – Process w In addition to that, depending on the development – Generate traffic – Automate the whole process w You would want it to be aware of your class or vendor specification

October 11, How to Get the Data You Need Capturing Traffic w Requirements depend on the application – Memory size (a sizable amount with flexible selection) – Triggering (comprehensive, but layered for ease-of-use) – Filtering (packet and transaction level) w You want to trigger on PIDs, Devices, Errors, Data Patterns etc. w You want to filter out: SOFs, Devices, NAK’ed w You want to be able to load and save customized sets of recording parameters

October 11, See What You Need the Way You Want Extensive Display Configuration w Great amount of data – You want important information to be available at a glance – You don’t want to see the fields you are not interested in w Color coding – Make the fields you are looking for stand out – Errors are highlighted in red w Zoom in and out, expand/collapse data fields w Individual packet fields can be hidden

October 11, The Power to Process Captured Traffic w Features you need – Search and Hiding u Layered from easy to complex u Fast invocation for easy search/hide – Reports ( Error, Traffic etc. ) – Timing calculations and Bandwidth display u Bandwidth calculations or graphical presentation – Data exports u Transfer data or protocol data u Exports to text in display format

October 11, And the Areas of Implementation The Layers of Decoding w View the protocol layers and their relationships – Packets – Transactions – Split transactions – Transfers w Need to be able to see decoded data – USB device requests – Formatted data on Interrupt or Bulk transfers w Ability to plug in your vendor-specific decoding

October 11, Sharing Information Between Developers w Free viewer, so everyone you want can take a look at your trace w Markers – Ability to write a comment to every packet in the trace u Helps you when you are looking at a complicated trace u Helps everyone who is looking at the trace after you are done w Export to text and other formats – Text can be inserted into or any other document, and also can be input to custom parsers

October 11, Shake Your Device to the Extreme Traffic Generation w Reasons you need something other then the host – Single packets/ transactions (silicon bring-up) – Host errors – No driver/application yet w How do you want it to look – Compatible with traces (recorded traffic) u Looks the same (or similar) u Can be exported, edited and re-sent – Text script language

October 11, Turn Your Analyzer Into a Test Station The Automation Interface w Software interface to perform analyzer functions in a script fashion (OLE, VB scripting etc.) w Some examples of what you can do – Automated connect/disconnect test – Generator scripts device tests – Data transfer tests (integrity, bandwidth) w Other applications (catching hard-to-repeat bug) w You need a well-documented interface with sample code

October 11, The More the Merrier Additional Features w On the other hand, you don’t want to be overwhelmed with features you don’t need w Not a must for everybody, but might become useful w Multiple channel recording – Mostly for hub development – Allows to simultaneously record upstream and downstream of a hub – Even more useful when speeds are different – Can help you to debug a problem with a hub even when you are a device developer

October 11, Know Thy Vendor Makers of USB Analyzers w Catalyst Enterprises – w CATC – w Crescent Heart Software – w Data Transit –

October 11, Learn More, Save More Time Conclusions w Demonstration of some of the discussed features – Layered display and decoding customization – Markers and other features w The conclusion – You save a lot of time by utilizing a bus/protocol analyzer during your development or testing – You can save even more time if you learn some key features of the analyzer and use them efficiently – Don’t hesitate to contact an analyzer vendor with your suggestions