Teledyne ENETbusD Decoder User Manual
Instruction
Manual
ENETbusD Decoder
ENETbusD Decoder Instruction Manual
© 2013 Teledyne LeCroy, Inc. All rights reserved.
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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 registered trademark of Teledyne LeCroy, Inc. Windows is a registered trademark
of Microsoft Corporation. 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.
922665 Rev A
March 2013
Instruction Manual
922665 Rev A
1
TABLE OF CONTENTS
Introduction .................................................................................................................. 2
About This Manual .................................................................................................................. 2
ENETbusD Option Overview .................................................................................................... 2
Serial Decode Technical Overview .......................................................................................... 3
General Approach .................................................................................................................... 3
Setting Up the Decoder .................................................................................................. 4
Enable/Disable Decoder .......................................................................................................... 5
Applying Measurements ......................................................................................................... 5
Working with the Decode Trace ..................................................................................... 7
Serial Decode Annotations ...................................................................................................... 7
Search Waveform .................................................................................................................... 8
Working with the Results Table ...................................................................................... 9
Customize Decode Result Table ............................................................................................ 10
Navigating with the Result Table ........................................................................................... 11
Export Decode Result Table .................................................................................................. 11
Teledyne LeCroy Service Centers .................................................................................. 12
ENETbusD Decoder
2
922665 Rev A
Introduction
About This Manual
Teledyne LeCroy offers different 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 ENETbusD toolset.
Assumptions
This manual is presented with the assumption that:
You have a basic understanding of the various serial data standard physical and protocol layer
specifications, and know how these standards are used in embedded controllers.
You have a basic understanding of how to use an oscilloscope, and specifically the Teledyne
LeCroy oscilloscope on which the serial trigger and decode option is installed. Only features
directly related to serial data decode are explained in this manual; please see the oscilloscope
online Help file, Operator's Manual, or Getting Started Manual for other instructions.
You have purchased and installed one of optional 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 firmware update from teledynelecroy.com.
While some of the screen images in this manual may not exactly match what is seen on your
oscilloscope display—or show an example taken from your protocol—be assured that the functionality is
nearly identical, as much functionality is shared.
ENETbusD Option Overview
Teledyne LeCroy ENETbusD is a software decode option for 10BASE-T and 100BASE-TX Ethernet, lowspeed serial data applications. With this software, you can easily decode 100BASE-T and 10BASE-T
Ethernet signals to examine each frame within a given packet, debugging problems such as
interoperability issues, uncertain error causes, and physical-layer issues.
10BASE-T and 100BASE-TX are Ethernet protocol standards used to send and receive data across
computer networks. As more and more devices are making use of the Ethernet protocol to
communicate in embedded systems, debugging the protocol becomes increasingly difficult. Engineers
need fast, reliable tools for debugging these embedded systems communication links. ENETbusD decode
offers color-coded overlay with easy-to-understand details on the data stream’s link layer. In addition,
powerful search capabilities allow you to search the acquired waveform in a myriad of ways.
Instruction Manual
922665 Rev A
3
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.
The first software algorithm examines the embedded clock for each message based on a default (or user
specified) vertical level. Once the clock signal is extracted or known, the algorithm examines the
corresponding data signal at a predetermined vertical level to determine whether a data bit is high or
low. The default vertical level is usually 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 point-based decode.
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 (Header/ID, Data Length Codes,
Data, CRC, Start Bits, Stop Bits, etc.) specific to the protocol.
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. In the case of the
shortest acquisition, all information is displayed (Header/ID, Data Length Codes, Data, CRC, Start Bits,
Stop Bits, etc.) with additional highlighting of the complete message frame.
General Approach
The order of your interaction with the decoder software in many ways mirrors the order of the
algorithms. You will:
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.
Complete the remaining dialogs required by your protocol/encoding scheme to decode
Transitions, Bits and Words.
Work with the decoded waveform and result table to analyze the decode.
While not required, we recommend the following general approach to 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.
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