I want to clarify:
At the beginning, Tx0 is connected to Rx1 and Tx1 is connected to Rx0 on the DS280DF810EVM Evaluation board by the bundled cable, the registers for the Tx0 and Rx1 channel were configured using the program for the Evaluation board DS280DF810EVM, where Tx0 is the PRBS generator and Rx1 is the receiver, and an eye chart was received but nothing was recorded in the registers for the Tx1 and Rx0 channels.
Then a board was drawn to generate the PRBS sequence and evaluate the eye diagrams on the received channel, built on the DS280DF810 chip. There the Tx0 channel is used to generate the PRBS, and the Rx1 channel is used to receive the PRBS. The transmitter and receiver of the DS280DF810 microcircuit are connected to each other through the corresponding connectors using the loop-back module. Register settings for the DS280DF810EVM debug board were used for our board. But the eye chart could not be obtained.
An experiment was conducted on the Evaluation board: in the version where we managed to get an eye diagram, disable the Tx1-> Rx0 pair, and Tx0 is connected to Rx1 as on our board. We apply the same register settings for the variant which I described at the beginning of the letter. At the same time, the eye diagram is falling apart.
Why does it happen?
Perhaps some mode is not configured?
Or it is necessary that 2 pairs of one group (for example Tx1-> Rx0, Tx0-> Rx1) must be connected for application in the topology of one transmitter and receiver, which are in the same group?
Figure 1 shows a part of our circuit, where the number 1 shows a transmitter and a 2-receiver connected to each other through the appropriate connectors using the loop-back module.
