DP83867ERGZ-R-EVM: Connecting two computers

Hi Michael,

Are you using SGMII or RGMII between the boards? The DP83867ERGZ-S-EVM should be used to validate SGMII, whereas the DP83867ERGZ-R-EVM would be for RGMII.

Michael Dubreuil said:

What is the minimum need to do to connect the boards?

If connecting the RJ-45s on both boards, no configuration is required. You can use a standard RJ-45 cable and can verify when the link is detected by monitoring LED_0 on both EVM boards. If you're trying to connect the RGMII interfaces, you can cross over the TX_D lanes from one evm to the RX_D lanes of the other. The same must be done with the respective CLK lanes. You may also need to adjust the CLK to data delay so the RGMII setup/hold times are valid on each PHY. This is done through register 0x0086:

Please note the RGMII interfaces are high speed signals that are sensitive to connection quality and channel length. While it is possible to link the RGMII interfaces of these EVM boards together, it is not a use-case we have validated.

Michael Dubreuil said:

When making reference to signals, please also reference the connector and pin number. For example, I can't find any documentation that tells me what pin TX_D0 is connected to on J3.

The EVM User's guide contains the board schematic. Here you can see where the PHY signals are connecting to:

For example, TX_D0 is connected to pin 25 of J3. I see this shown on the board's silkscreen as well:

Best,

Shane