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DP83867IS: IC can be used for 1000Base-KX or not.

Vyshnav vk
Intellectual 440 points
Part Number: DP83867IS
Other Parts Discussed in Thread: DP83869, DP83869HM, DP83869EVM

Hi TI Team,

We are planning to use DP83867ISRGZ IC in our next design for 1G Ethernet Interface. Our MAC will support 1000Base-KX / SGMII Configuration.

Can we use the same IC for our requirement. Whether DP83867ISRGZ can be used for 1000Base-KX configuration. 

Please provide your valuable input to proceed further.

Best Regards,

Vyshnav Krishnan

  • 0
    TI__Genius 11725 points

    Hi Vyshnav,

    Please refer to linked thread: https://e2e.ti.com/support/interface/f/interface-forum/798354/1000base-kx-to-10-100-tx-conversion

    Thank you,

    Nikhil

    All information in this correspondence and in any related correspondence is provided “as is” and “with all faults”, and it is subject to TI’s Important Notice (http://www.ti.com/corp/docs/legal/important-notice.shtml).

  • 0
    Intellectual 440 points

    Hi Nikhil,

    Thank you so much for your quick response. As per the discussion happened in above thread, the DP83867 can be used for 10/100M application. 

    Could you please confirm that, we can use the same for our 1000Base-KX 1G requirement also.

    Regards,

    Vyshnav Krishnan

  • +1 in reply to Vyshnav vk
    TI__Genius 11725 points

    Hi Vyshnav,

    This should be ok if the device is set or force mode (force 1G speed.) Please let me know if you have any further questions on this topic. Else, I will close this thread.

    Thank you,

    Nikhil

    All information in this correspondence and in any related correspondence is provided “as is” and “with all faults”, and it is subject to TI’s Important Notice (http://www.ti.com/corp/docs/legal/important-notice.shtml).

  • 0 in reply to Nikhil Menon
    Intellectual 440 points

    Hi Nikhil,

    Thank you for your support.

    Regards,

    Vyshnav Krishnan

  • 0 in reply to Vyshnav vk
    Intellectual 440 points

    Hi Nikhil,

    Could you please provide more information on, how to configure DP83867IS to work for 1000BaseKX. 

    Also what is the major difference between 1000BaseTX and 1000BaseKX. ? Please help us to take care this in design.

    Regards,

    Vyshnav Krishnan

  • 0 in reply to Vyshnav vk
    TI__Genius 11725 points

    Hi Vyshnav,

    1000Base-KX standard has a different voltage output swing from 1000Base-TX standard. You may review IEEE 802.3 spec for output swing for 1000Base-KX and 1000Base-TX. When using DP83867 in 1G force mode, this should be ok as long as output swing is adjusted from one device to the other.

    Thank you,

    Nikhil

  • 0 in reply to Nikhil Menon
    Intellectual 440 points

    Hi Nikhil,

    We would like to understand how to set the PHY to 1G forced mode, is it via MDI signals?
    Also can we get more information on whether 1000BASE-KX does not support auto negotiation?
    We are still not clear on how the PHY will take care 1000BASE-KX as the protocol supported by this is 1000BASE-T.
    As we checked online we where able to deduce that the difference between 1000BASE-KX and 1000BASE-T is the transmission medium, one is for back-plane and another is for twisted pair cable.
    we are new to this design and we are not able to conclude on whether to go ahead with this chipset, so we are double checking on the protocol that is supported by the PHY.

    We are very sure that our chipset will operate in 1000BASE-KX mode only and doesn't have any other mode.
    Since this is an important interface for our application we are very concerned on this interface and the part.

    Please let us know some more details on this.

    Thanks & Regards,

    Vyshnav Krishnan

  • 0 in reply to Vyshnav vk
    TI__Genius 11725 points

    Hi Vyshnav,

    PHY can be forced to 1G mode through register settings, write register 0x0 = 0x0140. 

    I am looking into your questions regarding differences between 1000Base-KX and 1000Base-T and will provide additional feedback by Thursday of this week.

    Thank you,

    Nikhil

  • 0 in reply to Nikhil Menon
    Intellectual 440 points

    Hi Nikhil,

    Thank you. How this can be done.? Via MDI signals.? Please provide more information on above query.

    Best Regards,

    Vyshnav Krishnan

  • 0 in reply to Vyshnav vk
    TI__Genius 11725 points

    Hi Vyshnav,

    I apologize for the confusion, please let me correct myself and clarify.1000Base-KX and 1000Base-T/1000Base-X auto-negotiation is technically not interoperable, if left to auto-negotiate, it will not resolve. 1000Base-KX should work with 1000Base-X (fiber mode), when both devices are forcing 1G speed. You may use the DP83869 in 1000Base-X mode. Again you must check that voltage output swing is met for both devices.

    Thank you,

    Nikhil

    All information in this correspondence and in any related correspondence is provided “as is” and “with all faults”, and it is subject to TI’s Important Notice (http://www.ti.com/corp/docs/legal/important-notice.shtml).

  • 0 in reply to Nikhil Menon
    Intellectual 440 points

    Hi Nikhil,

    Thank you so much for the clarification. I have few queries regarding this IC.

    1. Whether DP83867 and DP83869 are footprint compatible.?

    2. The procedure for setting forced 1G mode  for DP83869  is same as that of DP83867.?

    3.  How to disable auto-negotiation/ how to configure this IC to work for 1000Base KX.?

    4. Is there any reference design available for DP83869 ? If yes please share the same.

    Best Regards,

     Vyshnav Krishnan

  • 0 in reply to Vyshnav vk
    TI__Genius 11725 points

    Hi Vyshnav,

    To answer your questions:

    1. DP83867 comes in multiple footprint variants. I recommend reviewing the datasheet for the specific device desired to confirm footprint information. The DP83867 RGZ package (48 pin) will be the same footprint as DP83869HM.

    2. Yes, same register write is used. 

    3. Can force DP83869HM to RGMII to 1000Base-X mode via straps or register 0x1DF. Please review register section 9.5 in the datasheet, particularly table 12 for the strap setting, and please review register 0x1DFcontents and section 9.4.8 for the register settings. When forcing 1000Base-X mode, communication should work with a device forced to 1000Base-KX mode. Please note that this is not a typical use case and has not been characterized. 

    4. You may look into DP83869EVM: https://www.ti.com/tool/DP83869EVM

    Thank you,

    Nikhil

    All information in this correspondence and in any related correspondence is provided “as is” and “with all faults”, and it is subject to TI’s Important Notice (http://www.ti.com/corp/docs/legal/important-notice.shtml).

  • 0 in reply to Nikhil Menon
    Intellectual 440 points

    Hi Nikhil,

    Thank you. One more query I would like to ask with you is, can we force DP83869 to SGMII to 1000Base-X mode and so that we can achieve communication with 1000Base-KX device.?

    Best Regards,

    Vyshnav Krishnan

  • +1 in reply to Vyshnav vk
    TI__Genius 11725 points

    Hi Vyshnav,

    SGMII to Fiber is not a supported mode by this device. From the datasheet, you can see the SIP, SIN, SOP, SON pins are used for both SGMII and Fiber applications, and cannot be used for both SGMII and Fiber communication at the same time. One possible solution would be to use two DP83869 devices, one in SGMII to RGMII and the second in RGMII to 1000Base-X, to create a "black box" that acts as an SGMII to 1000Base-X interface.

    Thank you,

    Nikhil

    All information in this correspondence and in any related correspondence is provided “as is” and “with all faults”, and it is subject to TI’s Important Notice (http://www.ti.com/corp/docs/legal/important-notice.shtml).

  • 0 in reply to Nikhil Menon
    Intellectual 440 points

    Hi Nikhil,

    As I mentioned earlier, our chipset ethernet MAC will give output as 1000Base-KX only and we need to connect this to RJ-45 Connector. In this case which PHY we need to use.? is it mandatory to use PHY.? Please clarfiy.

    Best Regards,

    Vyshnav Krishnan

  • 0 in reply to Vyshnav vk
    TI__Genius 11725 points

    Hi Vyshnav,

    As mentioned, 1000Base-KX should work with 1000Base-X (fiber mode), when both devices are forcing 1G speed. You may use the DP83869 in 1000Base-X mode. Again you must check that voltage output swing is met for both devices. Please note that this is not a typical use case and has not been characterized.

    Thank you,

    Nikhil

    All information in this correspondence and in any related correspondence is provided “as is” and “with all faults”, and it is subject to TI’s Important Notice (http://www.ti.com/corp/docs/legal/important-notice.shtml).

  • 0 in reply to Nikhil Menon
    Intellectual 440 points

    Hi Nikhil,

    As per your input we are planning to use DP83869 IC. Could you please verify the below attached block diagram of Ethernet interface and please provide your feedback.

    Best Regards,

    Vyshnav Krishnan

  • 0 in reply to Nikhil Menon
    Intellectual 440 points

    Hi Nikhil,

    I kindly request you to provide your valuable input on the block diagram.

    Best Regards,

    Vyshnav Krishnan

  • 0 in reply to Vyshnav vk
    TI__Genius 11725 points

    Hi Vyshnav,

    Apologies for the delay. Will confirm block diagram design internally and provide feedback by Wednesday of this week.

    Thank you,

    Nikhil

    All information in this correspondence and in any related correspondence is provided “AS IS” and “with all faults”, and it is subject to TI’s Important Notice (http://www.ti.com/corp/docs/legal/important-notice.shtml).

  • 0 in reply to Nikhil Menon
    TI__Genius 11725 points

    Hi Vyshnav,

    This block diagram looks correct using the Fiber interface between the 1000Base-KX device and the DP83869. However, I want to reiterate that this is not a typical use case and performance between DP83869 over the 1000Base-KX interface has not been characterized. Performance will not be guaranteed by the datasheet, though this configuration should work given voltage output swing specs are met on both sides. Please perform your own evaluation.

    Please let me know if you have any further questions. Else, I will close this thread.

    Thank you,

    Nikhil

    All information in this correspondence and in any related correspondence is provided “AS IS” and “with all faults”, and it is subject to TI’s Important Notice (http://www.ti.com/corp/docs/legal/important-notice.shtml).

  • 0 in reply to Nikhil Menon
    Intellectual 440 points

    Hi Nikhil,

    Thank you for the clarification. I hope in future we can expect your support during testing stage

    Best Regards,

    Vyshnav Krishnan