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DP83630: If PHY support IEEE1588 feature(DP83630), the MAC(SoC) is no need extra HW requirement, am I right?

Part Number: DP83630

Dear Expert.

I am new for IEEE1588.

I have a design involving a IEEE 1588-2008 Precision Time Protocol (PTPv2) for synchronization to our system.

As my study, I will using DP83630 PHY to our system which support IEEE1588 ptp feature.

Here is my feature.

01)_MII interface, 10/100

02)_Run Linux daemon in MAC(SoC)

03)_Implement  IEEE1588 PHY(DP83630)

From my point of view, If PHY support IEEE1588 feature(DP83630), the MAC(SoC) is no extra HW requirement, am I right?

Thanks.

Isaac.

  • Hi Isaac that is correct.

    The hardware timestamping occurs in the PHY for the DP83630. Is there a reason your design requires the ptp feature? Our newer devices  such as the DP883867 supports SFD interrupt which can be used to timestamp the packet in the MAC. This is a software support for implementing 1588v1 and v2 where the actual timestamping happens in the MAC.

    Thanks,

    Cecilia

  • Hi Cecilia:

    It's great get your replay.

    I would like double confirm with you DP883867.
    I can't search the DP883867 information but DP83867.
    Is DP883867 newest product?

    I reviewed the DP83867 briefly.

    DP83867 didn't support MII interface. (Our MAC support MII interface with 10/100 only)

    From my study, DP83630 support 12 IEEE 1588 GPIOs for Trigger or Capture.

    Is DP83630 not support SPD interface to MAC?

    We would like to implement IEEE1588 V2 in our System.

    Our MAC didn't HW support the IEEE1588 V2.

    I was found the block as below from TI website.
    IEEE1588

    I also got the Linuxptp reference code from internet.

    That's why, I would like to using a Hardware PHY(DP83630) and ptp SW stack run our MAC to support IEEE1588 V2.

    Linuxptp Stack Features Linuxptp support the following features:

      • • Ordinary/Boundary Clock
      • • Best master clock algorithm
      • • Transport over UDP/IPv4, UDP/IPv6, and IEEE 802.3
      • • Transparent clock (E2E/P2P)
      • • Slave only
      • • Supporting IEEE 802.1AS-2011 in the role of end station

    Thanks.

  • Hi Isaac,

    My apologies on the typo it should be the DP83867. Per the datasheet, the DP83867 does in fact support MII.

    Thanks

    Cecilia

  • Hi Cecilia:

    Thanks your information.

    I double check the DP89867, Yes, it's support MII. Thanks you correct me.

    If we using MAC(No hardware support) + IEEE1588 PHY(DP83630) + IEEE1588 ptp software, May I know the accuracy is achieve which level (micro second, Nano second )?

    I reviewed the application "AN-1728 IEEE 1588 Precision Time Protocol Time Synchronization Performance".

    From below picture, the time accuracy is depend on MAC, 1588PTP and PHY.

    It's seem if our system accuracy require is around 100us. we can using  MAC(No hardware support) + PHY(no support ieee1588) + IEEE1588 ptp software.

    Would you please to give us advice for my point of view? thanks.

  • Hi Isaac,

    Per our datasheet the timestamping resolution is 8ns however there are more details available in our datasheet in section 2.3.3.2 1588 Event Timestamping 

    Thanks,

    Cecilia