Teledyne LeCroy Inspector - Users Manual - Manual (Page 23)

CATC CATC Inspector User’s Manual Version 2.31
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4.4.1.1 Trigger Selection
The CATC Inspector supports four modes of data recording triggering:
•
Manual
•
External Start
•
External Stop
•
Event Trigger
The external trigger modes work in conjunction with the trigger (active low) input on the
External Interface Breakout Board, as previously described under “External Triggers”.
4.4.1.1.1 Manual Trigger
In this mode, the analyzer will start to record when the user activates the “REC” icon or “Start”
in the Record Menu, and stop when the CATC Inspector on-board buffer memory is full or when
the “STOP” icon (or menu function) is activated, whichever comes first.
4.4.1.1.2 External Start Trigger
In this mode, the analyzer starts recording when an external trigger signal is detected. This
permits recording following a specific point of interest (aided by external decoding).
It is still necessary to “arm” the Inspector software by activating the “REC” icon or “Start” in the
Record Menu. Actual recording will begin following detection of an external trigger signal, and
stop when the CATC Inspector on-board buffer memory is full or when the “STOP” icon (or
menu function) is activated, whichever comes first.
4.4.1.1.3 External Stop Trigger
In this mode the analyzer stops recording when an external trigger signal is detected. This
permits recording up to a specific point of interest (aided by external decoding).
The operation is initialized by activating the “REC” icon or “Start” in the Record Menu. At
which time the analyzer will start recording immediately, and continuously, until it detects the
external trigger signal, or when the “STOP” icon (or menu function) is activated, whichever
comes first. The system’s buffer memory is filled cyclically until the stop trigger occurs, and thus
will hold (a maximum of) the last megabyte of USB data that appeared on the bus prior to the
trigger.
4.4.1.1.4 Event Trigger
In this mode, the analyzer will record the USB traffic stream surrounding the detection of one or
more specific events. These events are selected by the user, and include:
•
a packet of a particular type
•
a specific frame number
•
a reference (Setup, In, or Out) to a particular address/endpoint
•
a distinctive value in a data packet
•
a protocol error condition (bad CRC, invalid PID, bit stuffing error)