ChipScope Pro Software and Cores User Guide
107
UG029 (v14.3) October 16, 2012
ChipScope Pro Analyzer Features
Scan Settings
The Virtex-7 and Kintex-7 GTX transceivers include a circuit called RX Eye Scan that
performs a comparison between the received data at two different locations in the sample
region:
•
At the optimal sampling location, called “Data Sample”
•
At sampling location offset in the horizontal and/or vertical direction, called “Offset
Sample”
If the bit value sampled at the “Data Sample” location and the “Offset Sample” location
match, then this not considered an error. However, if the two bit values do not match, then
this is considered an error bit and causes the bit error ratio (BER) to increase.
The GTX RX Margin Analysis feature supports two different scan algorithms:
•
2D Full Scan: Scans all horizontal and vertical offset sampling points within the “eye”.
This mode is useful for creating a statistical eye map used to analyze the entire two-
dimensional received eye margin.
•
1D Bathtub: Scans all horizontal sampling points through the 0 vertical row offset.
This mode is useful for performing quick analysis of received phase margin.
The horizontal and vertical offsets can be controlled independently. Each offset can be
controlled to have an interval and range. The Range combo box controls the maximum and
minimum offset values of the scan. The Interval combo box controls how many rows or
columns are skipped between each row or column that is scanned.
Test Controls
After the sweep test has been set up, the test can be started by clicking the Start button.
After the Start button is clicked, the sweep parameter table is disabled and the test starts
running.
As the sweep test runs, the current sweep result file, current iteration, elapsed time, and
estimated time remaining status indicators are displayed. The sweep results are shown in
the Sweep Test Log text area near the bottom of the screen. The sweep test can be paused
by clicking on the Pause button or stopped completely by clicking on the Stop & Reset
button.
The results from a sweep test are displayed in the Test Results panel and are also sent to a
sweep test result file. Clicking on the Log File Settings button brings up the dialog window.
You can set both the location of the file and the number of sweep iterations stored in each
file. If the total number of sweep iterations exceeds the file limit, multiple files with starting
iteration number appended to the base file name are created in the same directory as the
initial result file.
The Dwell controls allow you to specify how long a measurement is taken at a particular
scan offset location. The BER option is used to specify the lowest bit error ratio that should
be achieved before moving to the next scan offset. The Time option is used to specify how
much time should be spent accumulating data before moving to the next scan offset.
Test Results
The Test Results panel shows the current iteration, elapsed time, and estimated time
remaining to complete the test. Below this status information are three tabbed panels
showing the results of the sweep test:
•
Sweep Test Log
•
Sweep Test Plots