Teledyne LeCroy SAS Suite User Manual - Manual (Page 152)

Version 6.25 SASSuite User Manual
142
LeCroy Corporation
Navigation - To move to the previous or next packet in the trace, click one of the two
buttons at the bottom of the window:
•
Prev - Displays data for the previous Frame in the trace.
•
Next - Moves to the next Frame in the trace.
Running Disparity Error - If SASSuite detects Running Disparity Errors it will display in
red and have exclamation marks before and after the value.
The 8-bit codes change to 10-bit codes before they get transmitted.
Running
Disparity
Running Disparity is a binary parameter with either the value negative (-) or the value
positive (+). After receiving any encoded character, the receiver shall determine whether
the encoded character is valid using the running disparity parameter as a checksum. The
receiver will then calculate a new value that is either the opposite of the previous
character or neutral. The ability to view changes in Running Disparity polarity is an
important part of the debug process. The raw bits view displays the running disparity of
the 10bit code in the column following the raw bits.
Note: For a more complete definition of Running Disparity, please refer to the Serial
Attached SCSI Specification (available at www.t10.org)