Teledyne USB2-HSIC User Manual
Instruction Manual
USB2/USB2-HSIC
Decode and Trigger
USB2/USB2-HSIC Decode and Trigger Instruction Manual
© 2014 Teledyne LeCroy, Inc. All rights reserved.
Unauthorized duplication of Teledyne LeCroy documentation materials other than for internal sales and
distribution purposes is strictly prohibited. However, clients are encouraged to distribute and duplicate
Teledyne LeCroy documentation for their own internal educational purposes.
Teledyne LeCroy is a trademark of Teledyne LeCroy, Inc. Other product or brand names are trademarks or
requested trademarks of their respective holders. Information in this publication supersedes all earlier
versions. Specifications are subject to change without notice.
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Contents
About This Manual 2
Assumptions 2
Compatibility 2
About the USB2 Options 3
Decode 3
Trigger 3
USB Decoding 4
Serial Decode Technical Overview 4
Decoding Workflow 5
Setting Up the Decoder 6
Working with the Decode Trace 9
Working with the Result Table 12
Applying Measurements with PROTObus MAG 14
USB Triggering 16
Serial Trigger Technical Overview 16
Linking Decoder to Trigger 16
USB2 Trigger Setup 17
Contact Teledyne LeCroy 21
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About This Manual
Teledyne LeCroy offers an array of toolsets for decoding and debugging serial data streams. These toolsets
may be purchased as optional software packages, or are provided standard with SDA and DDA model
oscilloscopes.
This manual explains how to use the following options.
l USB2.0 Decoder and Serial Trigger
l USB-HSIC Decoder
Assumptions
This manual is presented with the assumption that:
l You have a basic understanding of the serial data standard physical and protocol layer specifications,
and know how these standards are used in embedded controllers.
l You have a basic understanding of how to use an oscilloscope, and specifically the Teledyne LeCroy
oscilloscope on which the option is installed. Only features directly related to serial data decode and
trigger are explained in this manual; please see the oscilloscope online Help file, Operator's Manual or
Getting Started Manual for other instructions.
l You have purchased and installed one of the serial data decoders described in this manual.
Compatibility
Teledyne LeCroy is constantly expanding coverage of serial data standards and updating software. Some
capabilities covered in this documentation may only be available with the latest version of our firmware. You
can download the free firmware update from teledynelecroy.com.
While some of the screen images in this manual may not exactly match what is on your oscilloscope
display—or show an example taken from another standard—be assured that the functionality is nearly
identical, as much functionality is shared.
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About the USB2 Options
USB 2.0 is a version of the Universal Serial Bus specification, which is used to connect a host controller
(typically a PC) to various devices. The 2.0 version brought a higher maximum bandwidth (480 Mb/s) and
features such as the Mini-B Connector, Battery Charging, and Micro-USB Cables and Connectors
specifications, to name a few.
High-Speed Inter-Chip (HSIC) technology communicates between microchips in an embedded sub-system
and leverages the traditional host-device topology of USB, utilizing a large amount of existing USB code. This
makes HSIC extremely lucrative in areas demanding fast time-to-market solutions, such as the mobile
industry including both smart phones and tablets.
USB standards are maintained by the non-profit USB Implementers Forum, Inc. (USB-IF). Additional
information, including specifications for specific versions, can be found on their website at www.usb.org/.
Decode
The USB2bus and USB2-HSIC decoder options apply software algorithms to extract packet-level data
consistent with the HSIC, USB 2.0, USB 1.1, and USB 1.0 standards from physical layer waveforms measured
on your oscilloscope. Token, Data, and Status information is displayed over the actual physical layer
waveforms, color-coded to provide fast, intuitive understanding of the relationship between USB packets and
other, time synchronous events.
Trigger
The USB2 TD (trigger and decode) option additionally allows triggering on predefined and user-defined
patterns in USB packets, errors, transactions, or bus events.
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USB Decoding
Serial Decode Technical Overview
The algorithms described here at a high level are used by all Teledyne LeCroy serial decoders sold for
oscilloscopes. They differ slightly for serial data signals that have a clock embedded in data or a clock
separate from data.
Bit-level Decoding
The first software algorithm examines the embedded clock for each message based on a default or userspecified vertical level. Once the clock signal is extracted or known, the algorithm examines the
corresponding data signal at the predetermined vertical level to determine whether a data bit is high or low.
The default vertical level is set to 50% and is determined from a measurement of peak amplitude of the
signals acquired by the oscilloscope. It can also be set to an absolute voltage level, if desired. The algorithm
intelligently applies a hysteresis to the rising and falling edge of the serial data signal to minimize the
chance of perturbations or ringing on the edge affecting the data bit decoding.
NOTE: Although the decoding algorithm is based on a clock extraction software algorithm using a vertical
level, the results returned are the same as those from a traditional protocol analyzer using sampling pointbased decode.
Logical Decoding
After determining individual data bit values, another algorithm performs a decoding of the serial data
message after separation of the underlying data bits into logical groups specific to the protocol (Header/ID,
Data Length Codes, Data, CRC, Start Bits, Stop Bits, etc.).
Message Decoding
Finally, another algorithm applies a color overlay with annotations to the decoded waveform to mark the
transitions in the signal. Decoded message data is displayed in tabular form below the grid. Various
compaction schemes are utilized to show the data during a long acquisition (many hundreds or thousands of
serial data messages) or a short acquisition (one serial data message acquisition). In the case of the
longest acquisition, only the most important information is highlighted, whereas in the case of the shortest
acquisition, all information is displayed with additional highlighting of the complete message frame.
User Interaction
The order of your interaction with the decoder software in many ways mirrors the order of the algorithms.
You will:
l Assign a protocol/encoding scheme, an input source, and a clock source (if necessary) to one of the
four decoder panels using the Serial Data and Decode Setup dialogs.
l Complete the remaining dialogs required by the protocol/encoding scheme to decode Transitions, Bits
and Words.
l Work with the decoded waveform, result table, and measurements to analyze the decode.
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Decoding Workflow
While not required, we recommend the following workflow for decoding:
1. Set up the decoder.
2. Acquire a single burst of relevant data, then run the decoder.
NOTE:If the sampling rate (SR) is insufficient to resolve the signal adequately based on the bit rate (BR)
setup or clock frequency, the protocol decoding is turned OFF to protect you from incorrect data. The
minimum SR:BR ratio required is 4:1. It is suggested that you use a slightly higher SR:BR ratio if possible,
and use significantly higher SR:BR ratios if you want to also view perturbations or other anomalies on your
serial data analog signal.
3. Use the various analysis tools to verify that transitions are being correctly decoded. Tune the decoder settings as needed.
4. Run the decoder on acquisitions of the desired length.
You can disable/enable the decoder as desired without having to repeat the set up and tuning provided the
basic signal characteristics do not change.
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Setting Up the Decoder
The main Serial Decode dialog allows you to preset up-to-four, independent decoders, Decode 1 to Decode
4. Each decoder can use different (or the same) protocols and data sources, or have other variations, giving
you maximum flexibility to compare different signals or view the same signal from multiple perspectives.
TIP: After completing setup for one decoder using the procedure below, you can quickly start setup for the
other decoders by using the Decode # buttons at the left of the Decode Setup dialog. You don't have to step
back to the Serial Decode dialog to start the setup. Controls with the same label on either dialog share the
same function.
1. Touch the Front Panel Serial Decode button (if available on your oscilloscope), or choose Analysis >
Serial Decode from the oscilloscope menu bar to access the Serial Decode dialog.
2. On the same row as the Decode # (shown below):
l Check On to enable the decoder now. This will let you view the decoding on screen as soon as
there is an acquisition, which helps to begin tuning. You can if you wish wait until all settings are
complete to enable the decoder.
l Select the desired Protocol to use. The selections will depend on the software options installed on
your instrument.
l Select the (Source) Data to be decoded. This can be any signal input channel (Cx), memory (Mx), or
math function (Fx).
l For HSIC decoders, enter the Strobe source channel under Clock.
3. Optionally, check Link To Trigger On to tie the decoder setup to an additional serial trigger setup.
NOTE: This checkbox will only appear if the oscilloscope is equipped with an activated a TD or TDM
package and any required serial trigger hardware.
4. Touch the Setup button (next to Search) to open the Decode Setup dialog. If you use this method rather
than the tab, your settings will be correctly pre-selected on the Decode Setup dialog.
5. Go on to complete the required USB2/USB2-HSIC settings on the right-hand dialogs next to the Decode
Setup dialog.
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