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DP83867IS: SGMII mode 4 Strap pin level

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Replies: 7

Views: 167

Part Number: DP83867IS

Hi Experts,

We are using DP83867IS. VDDIO is 1.8 V and SGMII mode is used. The datasheet says as following on page 35.

For SGMII Mode 4 strap, TI recommends using Rhi = 4 kΩ and Rlo = 10 kΩ on RX_D0 and RX_D1 , RX_D2 and RX_D3.

What does "For SGMII mode 4 strap" mean? When using SGMII mode by setting LED_0 pin to mode 2 or mode 4 by using the Rhi and Rlo listed on table 5, Rhi is 4K and Rlo is 10K used for RX_D0, RX_D1, RX_D2 and RX_D3 pin. Correct?

When calculating STRAP pin voltage, it would be 0.98V while the table 5 shows min voltage is 0.694 x VDDIO = 1.25V. 

Do I miss anything?

Regards,

Uchikoshi

  • Hi Hisao,

    I do see this discrepancy.

    Right now I am working with my team to see why this note is in there and if there is a typo.

    Best regards,

    Ross Pimentel

    Ethernet - Applications Engineer

  • In reply to Ross Pimentel:

    Hi Ross,

    Can I hear any update?

    Regards,

    Uchikoshi

  • In reply to Hisao Uchikoshi:

    Hi Uchikoshi-san,

    We will need some more time to get back to you.

    Please give us a week to look into this further.

    Best regards,

    Ross Pimentel

    Ethernet - Applications Engineer

  • In reply to Ross Pimentel:

    Hello Ross,

    Can I get any feedback from you?

    Regards,

    Uchikoshi

  • In reply to Hisao Uchikoshi:

    Hi Uchikoshi,

    Please follow the note in the DS.

    When the device is operated in SGMII mode, the bootstrap threshold table does not apply to the SGMII pins.

    The resistor values for MODE 4 when in SGMII must be followed.

    Best regards,

    Ross Pimentel

    Ethernet - Applications Engineer

  • In reply to Ross Pimentel:

    Hi Ross,

    I understand that in SGMII mode and set to MODE 4, the table can be ignored and follow the note.

    So how accurate register should we use for the case to set MODE 4 in SGMII mode?

    Regards,

    Uchikoshi

  • In reply to Hisao Uchikoshi:

    Hi Uchikoshi-san,

    They shall be 1% precision.

    Regards,

    Geet