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ChipScope Pro Software and Cores User Guide
UG029 (v14.3) October 16, 2012
Chapter 4:
Using the ChipScope Pro Analyzer
RX Margin Analysis Panel
Use the RX Margin Analysis panel to set up a channel test that sweeps through various
transceiver settings to help find the optimal channel settings. The TX and RX settings
shown in this panel are for the same GTX transceiver. Sweeping through both TX and RX
settings only works if the transceiver is set to one of the near-end or external loopback
modes. Sweeping through RX parameters only can be performed when the corresponding
TX endpoint for the link resides in a different device or a different transceiver in the same
device.
The tabbed Sweep Test Settings panel consists of four sections: MGT/Parameter Settings,
Scan Settings, Test Controls, and Test Results.
MGT/Parameter Settings
Use the MGT combo box to select the GTX transceiver that will participate in the sweep
test.
Note:
Only one GTX transceiver can be swept at a time.
Before setting up the sweep test, set up the sweep parameters. While you can use any GTX
parameters during the parameter sweep operation, the most useful GTX 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 are shown in the Total Iterations field.