Teledyne LeCroy USBTracer_Trainer - Users Manual - Manual (Page 273)

USB Protocol Suite User Manual Chapter 10: Recording Options
LeCroy Corporation
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Note: If you are trying to match less than 16 bytes of data and want it to match the pattern
in a data payload which might be less than 16 bytes, align your pattern to the END of the
16 byte mask/match array. For example, if you want to match the SCSI header “USBS”
in a payload that MIGHT be less than 16 bytes, you would fill out the table as follows:
This will match the pattern in a payload of sizes 4 through 1024.
10.5.8 Counters and Timers for USB 2.0
Timer: A timer counts the time from a starting event to a final event. For example, if you
enter 10, the Analyzer counts 10 nanoseconds or milliseconds after the starting event
before it performs whatever action you assign. Timers cannot be applied to events with
Filter Actions. The maximum timer value is 65,535.
Counter: A counter tells the Analyzer to search for x instances of the selected event. For
example, if you enter 10, the Analyzer counts 10 instances of the selected event before
it performs whatever action you assign. Counters cannot be applied to events with Filter
Actions. The maximum counter value is 65,535.
Triggers can be set on multiple instances of an event. For example, you can set a trigger
to occur following five instances of any DLP. To configure the Analyzer to look for multiple
events, you enable Counters. Counters tell the Analyzer how many occurrences of an
event for which it should wait before triggering. For example, use a counter to Trigger
following the 16th occurrence of an error or DLLP message.
Events and Actions
Within events, counters determine how many times the event must occur before the
associated actions are triggered. Event counters typically have two properties:
• Count Randomly: Can be set to “Yes” or “No” (default value is “No”). If set to “Yes”,
the event repeats a random number of times (between 1 and the value set in the
property Max Random Count, which replaces the property Counter Value when
“Yes” is selected), before the action is triggered.
• Counter Value: Number of repeats required when Count Randomly is set to “No”.
The default value is 1.