LeCroy Corporation
Verification Script Engine Reference Manual
Page 10 of 107
3
Interaction between Application and Verification
Script
The following steps describe the interaction between the application and a verification script run over a recorded
trace:
1. Before sending any information to the script main processing function
ProcessEvent()
(which must be
present in any verification script),VSE looks for function
OnStartScript()
and calls it if it is found. In this
function, some setup routines can be made, like specifying the channels, specifying the trace events to
pass to the script, and setting up initial values of the global script-specific global variables.
2. Then VSE goes through the recorded trace and checks if the current frame in the trace meets specified
sending criteria. If it does, VSE calls the script main processing function
ProcessEvent(),
providing
some information about the current event in the script input context variables.
(See the topic “Input context variables” below in this document for a full description of verification script
input context variables.)
3.
ProcessEvent()
is the main verification routine, in which all processing of incoming trace events is done.
Basically, when the whole verification program consists of a few stages, this function processes the
event sent to the script, verifies that information contained in the event is appropriate for the current
stage, and decides if VSE should continue script running. If the whole result is clear on the current
stage, it tells VSE to complete execution of the script.
The completion of the test before the whole trace has been evaluated is usually done by setting the
output context variable:
out.Result = _VERIFICATION_PASSED
or
_VERIFICATION_FAILED
.
(See the topic “Output context variables” below in this document for a full description of verification script
output context variables.)
Note:
Not only does a verification script verify recorded traces by some criteria, but it is also possible to
extract some information of interest and post-process it later by third-party applications. (There is a set
of script functions to save extracted data in text or binary files or send it to other applications via
COM/Automation™ interfaces.)
1
When script running is finished, VSE looks for the function
OnFinishScript()
and calls it if it is found. In
this function, some resetting procedures can be done.
The following picture presents the interaction between the application and a running verification script:
