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Using a Beagle USB Protocol Analyzer, How Do I Trigger and Capture Data?
Rena Ayeras

Question from the Customer:

I am using the Beagle USB 480 Protocol Analyzer. I read through all the documentation, but could not find anything that fully explains how to enable triggers. Also, that feature is grayed out in the Data Center Software under Device Settings.

How do I enable the triggers? Also, can you tell me about the Digital I/O?

Response from Technical Support:

Thank you for your question! The Beagle USB 480 Protocol Analyzer does not support the trigger function - that option is supported by the Beagle USB 480 Power Protocol Analyzer – Ultimate Edition. However, the Beagle USB 480 analyzer can display Digital I/O pin event changes in the transaction window of the Data Center Software.

High Speed Beagle USB 480 Protocol Analyzer Beagle USB 480 Power Protocol Analzyer - Ultimate Edition

How to Trigger a USB Data Capture with an Advanced USB Protocol Analyzer

The Beagle USB 480 Power and Beagle USB 5000 v2 analyzers support triggering a capture when a defined pattern of events and/or data transactions occur on the bus.

The following video shows how to how to create a multi-state complex match system, trigger a USB capture, and view pre-trigger information.  For more information, please refer to the sections Triggering a Capture, Capture Control and Device Settings of the Data Center Software User Manual.

Digital I/O and the Beagle USB 480 Protocol Analyzer

Here are descriptions of how the Digital I/O works.  For more information, please refer to the subsections Digital Inputs and Digital Outputs in the Beagle USB 480 Protocol Analyzer Specifics section of the Beagle Protocol Analyzer User Manual.

Digital Inputs

Digital inputs allow you to synchronize external logic with the analyzed USB data stream. When the state of an enabled digital input changes, an event is sent to the analysis PC. The digital input should not oscillate faster than 30 MHz – at higher rates, the events may not be passed to the analysis computer.

When an active data packet is on the bus, only one input event will be recorded and sent back to the analysis computer. Once the packet has completed, the latest state of the lines, if changed, will be sent back to the analysis computer. Digital inputs are rated for 3.3V.

Hardware Filter Options

The hardware filter options enable the Beagle USB 480 and 5000 analyzers to discard some common packet groups, which reduces the amount of capture data received. Some of these packet groups correspond to polling operations - these sequences do not contain actual data transfer information.

Note - if there is a change in the digital input lines in the middle of one of the packet groups that is being filtered, that group will not be discarded. This preserves the context for the digital input line change.

The hardware filter options are:

  • SOF – Discard Start-of-Frame packets.
  • IN – Discard IN+ACK and IN+NAK packet groups.
  • PING – Discard PING+NAK packet groups.
  • PRE – Discard all PRE tokens.

SPLIT Option

The SPLIT option causes the hardware to discard many polling split packet groups. Following are the split groups that would be discarded:


Digital Outputs

Digital outputs enable outputting events to external devices, such as an oscilloscope or logic analyzer, such as triggering the oscilloscope to capture data. Digital outputs can be set to activate on various conditions. The digital outputs are rated to 3.3 V and 10 mA.

Advanced Beagle USB Protocol Analyzer Features

The Beagle USB 480 Power analyzer captures both USB data and power measurements in real time. There are two versions of the Beagle USB 480 Power Protocol Analyzer: Standard and Ultimate Edition. Both models provide the following features:

  • Full-speed, and Low-Speed USB 2.0 (480 Mbps / 12 Mbps / 1.5 Mbps)
  • Monitor current and voltage
  • Graph real time VBUS current and voltage values
  • Interactive and bi-directional correlation of current/voltage values with the USB data -High-Performance Hardware Buffer
  • Multiple digital inputs and outputs for synchronizing with external devices, and VBUS current and voltage monitoring
  • Real time USB class-level decoding with the Data Center Software
  • Detect suspend/resume events and unexpected signals
  • High-speed USB chirp detection, robust automatic speed detection, advanced triggering
  • Two capture modes: real time and delayed-download
  • 256 MB capacity
  • Large circular buffer

Ultimate Edition and Triggering

In addition to the Standard features, the Beagle USB 480 Power Protocol Analyzer - Ultimate Edition can trigger on a rise or drop in VBUS current or voltage.

The Ultimate Edition supports the following features (supported by the Standard Edition with the USB 2.0 upgrade package).

  • USB 2.0 Advanced Triggering Capabilities
  • Create state-based and flexible trigger conditions based on data patterns, packet types, error types, events, and other criteria
  • Hardware packet filtering
  • Up to eight independent states and six matches per state for USB 2.0 captures

We hope this answers your questions. Additional resources that you may find helpful include the following:

More questions? Send us an email at sales@totalphase.com. You can also contact us and request a demo that applies to your application.

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