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DP83848C: Supporting of IEEE Standard 802.1

Achiam Tanami
Prodigy 60 points
Part Number: DP83848C
Other Parts Discussed in Thread: DP83640, DP83630

Hello,

Does DP83848CVV/NOPB support the following IEEE standards?

- IEEE 802.1AS (2011)

- IEEE 802.1Qav (2009)

- IEEE Std. 802.1Qat (2010)

Thanks in advance,

Achiam Tanami.

  • 0
    TI__Mastermind 19780 points
    Hi Achiam,

    IEEE 802.1 standards are a profile of IEEE 1588 which requires PTP packet time stamping. This time stamping can occur in the MAC layer or the PHY layer depending on requirements of the system.

    To clarify, 802.1 does not have any PHY specific requirements. If the system being designed requires 802.1 time synchronization time error to be in the sub-nanosecond range, then the PHY will need to perform some actions like time stamping ,or maintaining the PTP clock.

    The DP83848C does not perform PTP packet time stamping itself, but it can be used with a MAC that performs/supports IEEE 802.1 standards.

    Best Regards,
  • 0 in reply to Rob Rodrigues
    Prodigy 60 points
    Hello Rob,

    Thank you for your fast response.

    I saw DP83640 supports IEEE 1588.

    If the MAC does not support IEEE 802.1, do you recommend to use DP83640 (or other TI Phy device) instead of DP83848C?

    Does one of TI Phys support AVB (Audio Video Bridge) standard?

    Sincerely,

    Achiam.
  • 0 in reply to Achiam Tanami
    TI__Mastermind 19780 points
    Hi Achiam,

    AVB contains the 802.1AS standard. They are agnostic of the PHY. AVB, when used for AV as advertised, does not require such high accuracy as 802.1AS may need.

    The DP83640 does support IEEE 1588 which is the underlying time sync mechanism for IEEE 802.1AS, 802.1 TSN, etc.

    Again it depends on your needs for the accuracy of the time error. I would suggest using a standard PHY like the DP83822 or the DP83867 if you need accuracy in the us range. If you need time accuracy tighter than that, then the DP83630/40 would be the part for you. Unfortunately we do not offer a PTP time stamping 1000BASE-T device as of today.

    Best Regards,
  • 0 in reply to Rob Rodrigues
    Prodigy 60 points

    Hello Rob,

    Thank you for your answer.

    Do you recommend to use DP83640 (or other TI Phy device) that supports IEEE 1588 instead of DP83848C?

    Does one of TI Phys support AVB (Audio Video Bridge) standard?

    Sincerely,

    Achiam.

  • 0 in reply to Achiam Tanami
    TI__Mastermind 19780 points
    Hi Achiam,

    All TI PHYs support AVB if the time synch is done in the MAC.

    For a low complexity solution with good time accuracy, I suggest using DP83822, or DP83848C.

    Best Regards,
  • 0 in reply to Rob Rodrigues
    Prodigy 60 points
    Hello Rob,

    What do you mean if "time synch is done in the MAC"?

    The board uses the ST controller STM32F427 that has MAC and the Phy DP8384CW/NOPB.

    Do this combination of STM32F427 and DP8384CW/NOPB support AVB and IEEE 1553 protocols?

    Sincerely,

    Achiam.
  • 0 in reply to Achiam Tanami
    TI__Mastermind 19780 points
    Hi Achiam,

    I cannot answer about the STM32F427 (has the Ethernet MAC). It does not matter what PHY you use if the STM32F427 does not support AVB/1588. You should ask this question to the ST team.

    Best Regards,
  • 0 in reply to Rob Rodrigues
    Prodigy 60 points
    Hello Rob,

    Thank you for your answers.

    In the your previous answer (30 April) you wrote: "All TI PHYs support AVB if the time synch is done in the MAC."

    What do you mean "if the time synch is done in the MAC"?

    Sincerely,

    Yacob Hassidim.
  • 0 in reply to Achiam Tanami
    TI__Mastermind 26320 points
    Hi Yacob,

    As mentioned by Rob, for AVB, you need 802.1AS and 1588 PTP.

    If MAC on Controller can perform 1588 and 802.1AS, you can use the DP83848.

    With DP83630/640, you will only get 1588 PTP not 802.1AS

    Hope it clarifies.


    Regards,
    Geet
  • 0 in reply to Geet Modi
    Prodigy 60 points
    Hello Geet,

    Thank you and Rob for your clarifications.

    Your clarifactions help me.

    I will ask the Controller supplier about 802.1AS and AVB.

    Sincerely,

    Achiam.