Teledyne LeCroy Detective - Users Manual - Manual (Page 16)

CATC CATC Detective User’s Manual Version 2.21
Page 13
4.2.2 USB Traffic Error Displays
The analyzer detects a variety of USB traffic errors, and displays them as follows:
Packet #3 above has an invalid PID value; the PID value field is colored red, and the rest of the
packet is marked as “Invalid Data”. Packets #4 and #5 have incorrect CRCs; the CRC value field
is colored red, as are the preceding fields associated with the CRC value. Packet #6 has bit
stuffing errors; the affected field is marked as “Invalid Data”, with any byte containing a bit
stuffing error bracketed with exclamation marks (“!”). When a bit stuffing error occurs, it is no
longer possible to determine the correct data byte boundaries; thus all affected data (through the
end of the packet) are collected into a field labeled “Invalid Data”, displaying the raw data
received, from left to right (regardless of the order specified in the Field Format Display
Options).
A related situation is the special case of Sync fields. Occasionally, the analyzer does not
synchronize with the data stream until part way through the Sync token; such situations are
marked by replacing the missed leading zero bits with underscore (“_”) characters. This situation
is not considered an error, but the analyzer reports only bits it has actually acquired.
In addition to packet errors, the Detective analyzer also detects a wide variety of transaction
errors. Reporting of these and other errors is discussed in section 4.6 (“The Report Menu”).
4.3 The File Menu
The file menu behaves as a standard Windows File menu, allowing the operator to open existing
analyzer traffic data files from previous sessions, save the data file from the current session,
create/edit data file comments, and print all or selected portions of the selected data file.