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DP83867IR: Strap Configuration

takishin
Expert 2360 points
Part Number: DP83867IR


Hi,

The default values of bit8(TX_FD),bit7(TX),bit6(10_FD) and bit5(10) of
ANAR Register(0x0004) are configured by strap pins.

I have a question.

Which strap pins are used for their configuration?

I could not find them on the Table 5. 4-Level Strap Pins.
And there is no description in the tables below.
Table 44. Strap Configuration Status Register 1 (STRAP_STS1), Address 0x006E
Table 45. Strap Configuration Status Register 2 (STRAP_STS2), Address 0x006F


Thank you in advance.

Best regards,
Takishin

  • 0
    TI__Mastermind 23675 points
    Hi Takishin,

    The bootstraps that control those are ANEG_SEL0 and ANEG_SEL1.
    Please refer to table 6 for details on how those bootstraps enable or disable the advertisement.
  • 0 in reply to Ross Pimentel
    Expert 2360 points
    Hi Ross,

    Thank you for your reply.

    But, I would like to know the default values of duplex mode for bit8(TX_FD) and bit6(10_FD) , too.
    The table 6 does not describe the duplex mode .


    I am looking forward to your reply.

    Best regards,

    Takishin
  • 0 in reply to takishin
    TI__Mastermind 23675 points
    Hi Takishin,

    Please refer to table 5, RX_D5 controls duplex. Force MDI is also on this pin as a bootstrap so you will need to pick one of the four bootstrap modes for the pin. By default, auto-mdix is enabled and full duplex is set since the internal pull-down will configure the PHY for mode 1.
  • 0 in reply to Ross Pimentel
    Expert 2360 points
    Hi Ross,

    Thank you for your quick response.

    I understand.

    I have one more question.

    If RX_D5 is set half duplex(mode 2 or mode 4),
    the device does not negotiate about the full duplex for 100base an 10 base in Auto-negotiation mode by not supported full duplex on bit8&6(ANAR register).
    (half duplex only negotiation for 100 base and 10 base in the Auto-negotiation mode)

    Is this correct?

    Best regards,

    Takishin
  • 0 in reply to takishin
    TI__Mastermind 23675 points
    Hi Takishin,

    RX_D5 will control half/full duplex advertisement for 10BASE-T, 100BASE-TX and 1000BASE-T.
    You are correct that the strap controls the auto-negotiation advertisement.
  • 0 in reply to Ross Pimentel
    Expert 2360 points
    Hi Ross,

    Thank you for your answer.

    You wrote,
    "RX_D5 will control half/full duplex advertisement for 10BASE-T, 100BASE-TX and 1000BASE-T."

    If so, the device negotiates about only full duplex for 100 base and 10 base in Auto-negotiation mode when RX_D5 is set full duplex(mode 1 or mode 3) .

    In general auto-negotiation, a local device negotiates about both full and half duplex for 100 base and 10 base.

    Is the DP83867IR different from other etherPHYs?

    Best regards,
    Takishin
  • 0 in reply to takishin
    TI__Mastermind 23675 points
    Hi Takishin,

    The DP83867IR is like other IEEE compliant PHYs.
    It will advertise 10BASE-T, 100BASE-TX and 1000BASE-T for both Full Duplex and Half Duplex.
    If you only want to advertise Half Duplex, you can use RX_D5 bootstrap to eliminate the Full Duplex advertisement.
    You can also enable/disable various advertisements for any speed through register access.
    It is not required for a PHY to have configuration options using bootstraps, but with the DP83867IR, we have many bootstrap configurations so that you can select a needed advertisement without using SMI.
  • 0 in reply to Ross Pimentel
    Expert 2360 points
    Hi Ross,

    Thank you for your clear explanation.
    I understand.

    Best regards,
    Takishin