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Serial Decode

Decoding Workflow

We recommend the following workflow for effective decoding:

1. Set up the decoder using the lowest level decoding mode available, but do not yet enable it.

2. Acquire at least one complete transmission reasonably well centered on screen in both directions, with

generous idle segments on both sides.

Note:

See

Failure to Decode

for more information about the required acquisition settings.

3. Stop acquisition, then enable the decoder. It will operate on the acquisition in buffer.

4. Use the various decoder tools to verify that transitions are being correctly decoded. Tune the decoder

settings as needed to produce a satisfactory decoding.

5. Once you are correctly decoding in one mode, continue making small acquisitions of five to eight

transmissions and run the decoder in higher level modes.

6. Finally, run the decoder on acquisitions of the desired length.

When you are satisfied the decoder is working properly, you can disable/enable the decoder as desired without
having to repeat this tuning process, provided the basic signal characteristics do not change.

Decoder Set Up

Use the Decode Setup dialog and its protocol-related subdialogs to configure decoders. Each decoder can use
different protocols and data sources, or have other variations, giving you maximum flexibility to compare different
signals or view the same signal from multiple perspectives.

1. Touch the Front Panel Serial Decode button (if available on your oscilloscope), or choose Analysis > Serial

Decode from the oscilloscope menu bar.

2. On the Serial Decode dialog, enable the decoder by checking On next to the decoder number. This may be

done any time, although we recommend having an acquisition in buffer before enabling the decoder.

3. Click the Setup button at the end of the row to open the Decode Setup dialog.

Note:

The full configuration can only be made from Decode Setup.

4. Enter the input channels (sources) and select the Protocol to be decoded. This selection will drive the other

fields that appear.

Note: Subdialog selections, such as single-ended or differential probing, may affect the input fields
that appear on the Decode Setup dialog.

5. Define the level of decoding on the subdialogs (see below) to the right of the Decode Setup dialog.

3

Содержание USB-PD TDMP

Страница 1: ...USB PD TDMP Trigger Decode Measure Graph and Physical Layer Tests...

Страница 2: ...le or unauthorized duplication of Teledyne LeCroy publications is strictly prohibited Teledyne LeCroy is a trademark of Teledyne LeCroy Inc Inc Other product or brand names are trademarks or requested...

Страница 3: ...Requirements 19 Restrictions 19 USB PD Trigger Setup 19 Linking Trigger and Decoder 21 Using the Decoder with the Trigger 21 Saving Trigger Data 22 Measure Graph 23 Serial Data Measurements 23 Graphin...

Страница 4: ...n is installed Only features specific to this product are explained in this manual While some images may not exactly match what is on your oscilloscope display or may show an example taken from anothe...

Страница 5: ...or a range of matching data The TDMP option adds a set of measurements designed for serial data analysis as well as physical layer tests defined by the standard The physical layer tests are based on...

Страница 6: ...ding 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 prot...

Страница 7: ...ng process provided the basic signal characteristics do not change Decoder Set Up Use the Decode Setup dialog and its protocol related subdialogs to configure decoders Each decoder can use different p...

Страница 8: ...Description showing the symbolic decoding of the hexadecimal data Select if you wish to Show 4b Symbols Select PS_RDY_LEVEL if you wish to measure VBUS PS_RDY If you check this be sure to specify the...

Страница 9: ...e decoder to make the VBUS PS_RDY measurement 1 Probe CC using one channel and VBUS using a second channel In this example CC is on C1and VBUS is on C2 which are entered in the corresponding fields on...

Страница 10: ...to that below For each instance of PS_RDY decoded on the CC1 CC2 channel the measured voltage on the VBUS channel is recorded in the PS_RDY_LEVEL column of the decoder result table The VBUS PS_RDY vol...

Страница 11: ...at there are a number of error frames make sure that Level is set to a reasonable value The optional Hysteresis setting imposes a limit above and below the measurement level that precludes measurement...

Страница 12: ...will appear The minimum number of bits required varies from one protocol to another but is usually between 5 and 50 l Poor signal quality Care must be taken when probing high speed serial data signal...

Страница 13: ...trace and the length of the acquisition Zooming a portion of the decoded trace by clicking a line in the table will reveal the detailed annotations Annotation Overlay Color 1 Text 2 Packet Navy Blue...

Страница 14: ...lumn is colorized to match the input source that resulted in that index Note The interleaved summary table will default to the lowest common decoding e g hexadecimal if both support that but only one...

Страница 15: ...l Decode Separate files for each decoder are saved in D Applications protocol The Save Table feature will automatically create tabular data files with each acquisition trigger The file names are autom...

Страница 16: ...cimal Object Object type Appears instead of Data when decoding Symbolic Bits Description Symbolic decoding of payload Appears instead of Data when decoding Symbolic CRC Cyclic Redundancy Check hex cod...

Страница 17: ...the zoom scale the highlighted area may expand to several rows of the table or fade to indicate that only a part of that Index is shown in the zoom When there are multiple decoders running each can ha...

Страница 18: ...con similar to Excel in the header cell and the index numbers will be colorized Example filtered decoder table On summary tables only the Time Protocol and Status columns can be filtered If you apply...

Страница 19: ...sed to flag out of tolerance messages messages outside the user defined bitrate tolerance by colorizing in red the Bitrate shown in the table Exporting Result Table Data You can manually export the de...

Страница 20: ...that column If you do not enter a Value Search goes to the beginning of the next data element of that type found in the acquisition l Enter a Left Right Pad the percentage of horizontal division aroun...

Страница 21: ...st segment trigger to the beginning of the sample segment Otherwise the results are the same as for other types of acquisitions and can be zoomed filtered searched or used to navigate When a Sequence...

Страница 22: ...each using different data or clock input sources This approach is statistically interesting because multi channel acquisitions occur in parallel The processing is serialized but the decoding of each...

Страница 23: ...hout using the serial trigger Requirements Serial trigger options require the appropriate hardware please consult support an installed option key and the latest firmware release Restrictions The seria...

Страница 24: ...the oscilloscope will trigger on finding the next matching occurrence in the data stream For Control Message triggers click inside the field to display the full set of available message types For Err...

Страница 25: ...s such as TriggerScan to inspect the waveform for events of interest Touch and drag the paused trace to show time pre or post trigger Optimize the Grid The initial decoding may be very compressed and...

Страница 26: ...he waveform at each trigger point These files can be recalled to the oscilloscope for later viewing Choose File Save Waveform and an Auto Save setting of Wrap overwrite when drive full or Fill stop wh...

Страница 27: ...ied set up of a Message to Value parameter and graph Performs a Digital to Analog Conversion DAC of the embedded digital data and dis plays it as an analog waveform Message to Value ID Value Extracts...

Страница 28: ...values and compare them to a corresponding analog signal or to observe changes in timing A parameter tracked over a long acquisition could provide information about the modulation of the parameter To...

Страница 29: ...Binary or Hex adecimal format 3 If the field appears select the Bits used to define the frame ID This will change the ID Value field length 4 Using the ID Condition and ID Value controls create a con...

Страница 30: ...to define the event in the Analog waveform that is to be used as the reference for the measurement As with the decoder Level may be set as a percentage of amplitude default or as an absolute voltage l...

Страница 31: ...ts 3 To gate measurements to only the zoomed areas e g a single index of the decoder table check Apply Only to Zoom 4 Open the Measure dialog select the test number USB PD n test Category and Measurem...

Страница 32: ...can occur when the bitrate is extremely close to a submultiple of the sampling rate such that the sampling of the waveform does not move throughout the entire unit interval Gaps can also occur when u...

Страница 33: ...the eye is Tested At Transmitter or Receiver 5 Check Mask Hit to add the number of mask failures to the standard Measure table not the PHY measurement table To show where mask failures occur on the ey...

Страница 34: ...Decode Decoden out Result cellvalue RowA ColA RowB ColB Where n 1 to 4 RowA 0 to K 0 Row Index Number ColA 0 to L 0 Column Header RowB 0 MeasuredValue 1 StartTime 2 StopTime ColB 0 to M Complicating t...

Страница 35: ...of your query would be 6 4 Within each column Simple Cells contain a single value that appears at the specified location in the table In the above example columns 0 through 2 are Simple Cells Simple C...

Страница 36: ...Col 12 vbs return app SerialDecode Decode1 out Result cellvalue 6 12 1 0 2 62461 E 03 StartTime of Data in ColB0 of Row 6 Col 12 hidden vbs return app SerialDecode Decode1 out Result cellvalue 6 12 2...

Страница 37: ...s are available to help you get the most out of your Teledyne LeCroy products Visit teledynelecroy com support techlib The Datasheet published on the product page contains the detailed product specifi...

Страница 38: ......

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