Teledyne LeCroy USBTracer_Trainer - Users Manual - Manual (Page 17)

USB Protocol Suite User Manual Chapter 1: Overview
LeCroy Corporation
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1.1.5 Real-Time Event Triggering and Capture Filtering
The Analyzer can accurately identify and selectively record transactions of interest from
the crowded stream of bus traffic. The system uses more than a dozen configurable
hardware building blocks that you can optimize to perform particular activities. Such
“recording resources” can independently await an initialization signal, monitor its external
environment (external signals or other resources) in search of a particular event, and take
a subsequent action, such as triggering, inclusive or exclusive filtering, and counting. In
the user interface, you can select, configure, and combine these resources to search for
complex trigger conditions and selectively capture associated transactions.
The system can trigger on basic events, such as specific bus conditions and
packet identifiers (PID). It can also trigger on complex events, such as “trigger on the
fifth occurrence of a SETUP Token device number nine” or “trigger on a SET INTERFACE
request, following a specified eight-byte bulk data pattern match from this scanner, and
do not capture any start-of-frame (SOF) packets.”
You can set the size of the recording memory, specify the pre-trigger to post-trigger
capture ratio, and truncate large data packets up to 256 bytes.
1.1.6 Advanced Event Counting and Sequencing
The count and sequence options define rules for data recording sessions. These options
configure and control the order of events selected for triggering or filtering.
Using this feature, you can specify a sequence of up to seven events that must occur
before the Analyzer triggers and finishes capturing data, allowing you to specify
event types for recording. Without this feature, you may have to scroll through megabytes
of recorded data to locate an occurrence of a sequence.
1.1.7 BusEngine Technology
The Analyzer uses LeCroy BusEngine Technology. The BusEngine core uses Electrically
Programmable Logic Device (EPLD) technology and incorporates both a real-time
recording engine and configurable building blocks that implement data/state/error
detection, triggering, capture filtering, external signal monitoring, and event counting and
sequencing. Like the flash-memory-based firmware that controls its operation, all
BusEngine logic is fully field upgradeable, using configuration files.