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DP83867IR: Different readings in the "DP83867IR/CR Robust, High Immunity 10/100/1000 Ethernet Physical Layer Transceiver datasheet (Rev. E)"

Ruslan Filipovich
Prodigy 70 points
Part Number: DP83867IR

I have two questions of the different reading in the datasheet:

1. I see page 45 from this datasheet. The page contained Table 4 "Strap Resistor Ratios". Now if you look at page 51, you see RX_D4 connected to ground via 2.49 kOm resistor. What is the selected mode for RX_D4? On 50 page i see "RX_D4 = Strap Mode 4". Is it mistake?

2. On Page 30 section 8.4.1 i see this text "The RGMII Disable strap (RX_D6) determines the default state of the MAC interface. The RGMII Disable strap corresponds to the RGMII Enable (bit 7) in the RGMIICTL register (address 0x0032). When RGMII mode is disabled, the DP83867 operates in GMII mode."

if the "RGMII Disable strap" = 0 the device uses RGMII mode, but if the "RGMII Enable bit" = 0 the device uses RMII mode. I think "RGMII Disable strap not corresponds to the RGMII Enable" or am i not right?

Please, answer of my questions.

Best regards, Ruslan

DP83867IR/CR Robust, High Immunity 10/100/1000 Ethernet Physical Layer Transceiver datasheet (Rev. E)

  • 0
    TI__Mastermind 19780 points
    Hi Ruslan,

    1. Yes, the strapping example shows an error. Thank you for indicating that error. I have recorded it for future revisions. To correct this error, the image in figure 7 should show the RX_D4 resistor of 2.49kR in a pull-up configuration.

    2. I think your confusion comes from the interaction between RGMII disable strap and RGMII_EN bit register 0x32.7. The RGMII disable strap sets the default value of the RGMII_EN bit, but it does not make the RGMII_EN bit read only. You may change the RGMII_EN during normal operation. So the RGMII disable strap does correspond to the RGMII_EN bit.

    Best Regards,
  • 0 in reply to Rob Rodrigues
    Prodigy 70 points

    Hi,

    Thank you very much for your response!

    The topic can be considered exhausted.

    Best regards, Ruslan