Teledyne LeCroy Serial Data Debug Solutions - Manual (Page 83)

Operator's Manual
919586 RevA 83
Include or exclude Channel Idle Delimiter (CID), CAS/MTS, or Wakeup Pattern from your trigger by
checking our un-checking as desired. Multiple values may be selected and included in your Symbol
trigger.
E RRORS T RIGGER S ETUP D ETAIL
4c. Protocol and CRC Errors - Error Trigger Only
When Errors is selected as the FlexRaybus trigger, use the Protocol and CRC Errors fields in the following
manner:

Protocol Errors - Include or exclude FSS, BSS, or FES errors from your trigger by checking our un-checking
as desired.

CRC Errors - Include or exclude Header CRC or Payload CRC errors from your trigger by checking our un-
checking as desired.

Payload Channel - If you include Payload CRC errors in your Error trigger, use this field to select the
correct channel.

Select all Errors and Deselect all Errors - Use these buttons to conveniently select or deselect all Protocol
and CRC Errors with a single click.
FlexRaybus Physical Layer and Eye Diagram Analysis
LeCroy's FlexRaybus option contains a software algorithm which creates eye diagrams, performs mask testing
and measures timing parameters as defined in the FlexRay specification. The algorithm creates eye diagrams by
slicing up all the bits transmitted in the FlexRay signal and superimposing each bit on to an eye diagram. The
signal is sliced based on measurements taken at the falling edge of the first Bytes Start Sequence (BSS) and the
time between consecutive BSS symbols. These measurements allow the algorithm to compute the rate of the
embedded clock and slice the FlexRay waveform in to sub-waveforms one bit in length. The clock uses a
constant bitrate specified by the user and is resynchronized on every BSS. These sub-waveforms are then scaled
to fill 8 horizontal divisions on the oscilloscope and represent 1 Unit Interval (UI) in the eye diagram and
superimposed on top of each other.
Mask testing can be performed on the eye diagram with masks defined at TP1 and TP4. The mask is aligned
horizontally by computing the time for a single UI and centering it on the display. The mask is centered vertically
around 0V.
Along with eye diagrams and mask testing the TDP option adds 4 FlexRay specific measurements to the
oscilloscope. These measurements are Propagation Delay, Asymmetric Delay, Truncation, and Jitter. They are
measured as defined in the FlexRay specification. These measurements characterize timing properties of the
propagation of signals along the communication channel.