ChipScope Pro Software and Cores User Guide
119
UG029 (v14.3) October 16, 2012
ChipScope Pro Analyzer Features
Before setting up the sweep test, set up the sweep parameters. While you can use any GTP
parameters during the parameter sweep operation, the most useful GTP transceiver
parameters available for sweep are the defaults:
•
TX Diff Swing
•
TX Pre-Cursor
•
TX Post-Cursor
To add or remove items in the table, click the
Add/Remove Parameters
button. This opens
a dialog box with all available ports/attributes on the left, and the ones to sweep on the
right. To add a new sweep parameter, first select the parameter in the left-hand list then
click the right arrow button to add it to the list on the right. To remove a parameter to
sweep, first select it in the right-hand list, and click the left arrow button. To specify the
sweep order of the parameters, click it in the right hand list, and then the
Up
or
Down
buttons. To revert the sweep attributes and their order to the default setting, click the
Reset
to Default
button. Click
OK
to apply the settings, or
Cancel
to exit without saving.
The sweep parameters can be initialized in one of the following ways:
•
Click the
Clear All Parameters
button to clear all parameters to the
Select…
option.
•
Click the
Set Parameters to Current Values
button to set the parameters to their
current values on the
MGT/BERT Settings
panel.
The order of the parameters in the
Sweep Parameter
table dictates how the parameters are
swept. The values of the parameters near the top of the table are swept less frequently than
the parameters near the bottom of the table. In other words, the parameters near the top of
the table are in the outer loops of the sweep algorithm while the parameters near the
bottom of the table are in the inner loops of the sweep algorithm.
Each parameter must be set up with a start and end value. The order of the parameter
values cannot be changed. After you select the start value, the end values available for
selection change automatically to include only valid selections. If you do not want to
sweep through a parameter, set the start and end values for that parameter to the same
value. The
Sweep Value Count
column indicates how many values are swept through for
a particular parameter. After all sweep parameters have valid start and end values, the
total number of sweep iterations is shown in the
Total Iterations
field.
Scan Settings
The Virtex-7 GTP 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 GTP 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.
