DP83867E: SGMII_COP connection to TMS320C6657

Steve Widener

Part Number: DP83867E
Other Parts Discussed in Thread: TMS320C6657,

Please provide a connection diagram for attaching the DP83867 to the TMS320C6657.

Is the SGMII_COP signal required? If so, how do those connect to the TMS320C6657 (SRIOSHGMIICLK is connected to the main clock source.

over 8 years ago

0 Aniruddha Khadye over 8 years ago

TI__Mastermind 18425 points

Hi Steve,

SI of DP83867E is the input to the PHY which will be transmitted by the PHY on the cable. When the PHY receives the data its transmitted on the SO pair to the MAC. So connect SI of DP83867E to TX of TMS320C6657 and SO to RX of TMS320C6657.

SGMII_COP/N is the clock for MAC. Some MAC's cannot recover clock from data and need external clock coming from the PHY. SGMII_COP should be connected to Positive of the SGMII clock on MAC and SGMII_CON should be connected to negative of negative of the SGMII clock on MAC. A brief look through the C6657 datasheet tell me that it does have input pins for SGMII clock. Please verify with the C6657 team that the MAC needs SGMII clock input or not.

All sgmii signals are differential signals and should be routed as such with 100ohm differential impedance. Please place 0.1uF AC coupling capacitors on all SGMII traces.

-Regards,
Aniruddha

0 Rob Rodrigues over 8 years ago in reply to Aniruddha Khadye

TI__Mastermind 19780 points

Hi Steve,

Here is a diagram of the connection Aniruddha described. The C6657 would also need connections to the MDIO interface at a minimum. The C6657 can perform clock recovery from the SGMII data so the CO signals are not needed.

Please verify the balls called out in the below schematic are correct!

Best Regards,

Interface

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DP83867E: SGMII_COP connection to TMS320C6657