LeCroy Advisor, Руководство пользователя

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USB Advisor User Manual Chapter 11: Recording Options
LeCroy Corporation
117
Options
Truncate Data Fields allows data fields to be truncated during recording to save
Analyzer memory and allow recording of more packets. Enter a maximum data length
value in the Bytes box. Advisor truncates the data to the stated value or slightly larger.
Note: Truncation of data may cause incorrect transaction or transfer decoding.
Beep When Trigger Occurs makes the computer connected to the Advisor beep three
times when a Trigger condition is first detected.
Auto-Merge 2 Channel Trace Files causes Advisor to merge traffic of two recording
channels into a file called data_merged.usb (or whatever name you wish to give it).
Advisor also makes two other files during this recording: data.usb and data_classic.usb
(or whatever names you choose to give them). If unchecked, Advisor create only two
files: one for Classic-Speed traffic and another for Hi-Speed traffic.
Save External Interface Signals causes Advisor to save signals from a Breakout Board
(pins TRIG IN - G.P. IN ) as fields in the trace.
Trigger/Filter Channel allows you to choose between Hi-Speed or Classic Speed. The
selected choice tells Advisor what channel it should use to perform its triggers/filters. The
last channel selected here is the one to be used for Triggering/Filtering.
Buffer Size
You can adjust the size of the recording buffer from 0.1 megabytes to 128 megabytes.
The Recording Type option determines how this buffer is used. Although there are 128
megabytes of physical memory in the Analyzer, the efficiency of the recording is about a
2:1 ratio of physical memory to actual USB traffic. Shorter USB packets yield a slightly
less efficient recording. The non-traffic portion of physical memory is utilized for control
and timing information.
Note: The scale is not linear and affords more granularity in the smaller buffer
sizes.
Trigger Position
You can adjust the amount of recording to be done post-Trigger or select where you want
the Trigger located within the defined buffer. You can adjust the Triggering Position
between 1 and 99% post-Trigger.
Trigger Position is available only when Manual
Trigger or Event Trigger is selected as Recording type .
As an example, if the buffer size is set to 16MB, then for the following Trigger Position
settings, the amount of pre- and post-Trigger data is
• 95% post-triggering: 0.8MB pre-trigger, 15.2MB post-trigger
• 75% post-triggering: 4MB pre-trigger, 12MB post-trigger
• 50% post-triggering: 8MB pre-trigger, 8MB post-trigger
• 25% post-triggering: 12MB pre-trigger, 4MB post-trigger
• 5% post-triggering: 15.2MB pre-trigger, 0.8MB post-trigger
Note: When a Trigger occurs, recording continues until the post-Trigger amount of
the buffer is filled or when
Stop is selected.