Viewing and Changing Links Settings Using the Links Window - 2024.1 English

Vivado Design Suite User Guide: Programming and Debugging (UG908)

Document ID
UG908
Release Date
2024-05-30
Version
2024.1 English

Once links are created, they are added to the Links view (see the following figure) which is the primary and best way to change link settings and view status.

Figure 1. Links Window

Each row in the Links window represents a link. Common and useful status and controls are enabled by default, so the health of the links can be quickly seen. The various settings that can be viewed in the Links window's table columns are shown in the following table.

Table 1. Links Window Settings
Link View Column Name Description
Name The name of the link
TX The GT location of the transmitter
RX The GT location of the receiver
Status If linked (meaning the incoming RX data as expected). Status displays the measured line rate. Otherwise, it displays "No Link".
Bits The measured number of bits received.
Errors The measured number of bit errors by the receiver.
BER Bit Error Ratio = (1 + Errors) / (Bits).
BERT Reset Resets the received bits and error counters.
RX Pattern Selects which pattern the receiver is expecting.
TX Pattern Selects which pattern the transmitter is sending.
TX Pre-Cursor Selects the pre-cursor emphasis on the transmitter.
TX Post-Cursor Selects the post-cursor emphasis on the transmitter.
TX Diff Swing Selects the differential swing values for the transmitter.
DFE Enabled Selects whether the Decision Feedback Equalizer is enabled on the receiver (not available for all architectures).
Inject Error Injects a single bit error into the transmit path.
TX Reset Resets the transmitter.
RX Reset Resets the receiver and BERT counters (see BERT Reset).
Loopback Mode

Selects the loopback mode on the receiver GT.

Warning: Changing this value might affect the link status depending on the system topology.
Termination Voltage Selects the termination voltage of the receiver.
RX Common Mode Selects the RX Common Mode setting of the receiver.
TXUSERCLK Freq Shows the measured TXUSERCLK frequency in MHz.
TXUSERCLK2 Freq Shows the measured TXUSERCLK2 frequency in MHz.
RXUSERCLK Freq Shows the measured RXUSERCLK frequency in MHz.
RXUSERCLK2 Freq Shows the measured RXUSERCLK2 frequency in MHz.
TX Polarity Invert Inverts the polarity of the transmitted data.
RX Polarity Invert Inverts the polarity of the received data.

It is possible to change the values of a given property for all links in a link group by changing the setting in the link group row. For instance, changing the TX Pattern to "PRBS 7-bit" in the "Link Group 0" row changes the TX Pattern of all the links to "PRBS 7-bit". If not all the links in the group have the same setting, "Multiple" appears for that column in the link group row.

When the In System IBERT IP is used in your design, only a subset of the link settings apply. The following table lists the applicable link settings.

Table 2. In System IBERT Link Window Settings
Link view column name Description
TX The GT location of the transmitter
RX The GT location of the receiver
TX Pre-Curser Selects the pre-curser emphasis on the transmitter.
TX Post-Cursor Selects the post-cursor emphasis on the transmitter.
TX Diff Swing Selects the differential swing values for the transmitter.
DFE Enabled Selects whether the Decision Feedback Equalizer is enabled on the receiver (not available for all architectures).