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AM3357: EtherCAT link and speed LED connections

Part Number: AM3357
Other Parts Discussed in Thread: DP83848T, , DP83848K, TLK110

Hi Sitara support Team,

Regarding the following my post, I would like ask additional question.
e2e.ti.com/.../2464289

I asked the combination of "DP83848T" and "AM3357" used by my customer.
However my customer try to change from "DP83848T" to "DP83848K".

If he will use "DP83848T" that has Link_SPEED pin, can he set LED MODE "2" with the following connection?

The custom board connects "LED_LINK" of DP83848K to LED of EtherCAT connector
and "LED_SPEED" of DP83848K to "pr1_mii0_rxlink" of AM3357.

Is this connection possible for the enhanced link detection?
Or should the custom board connect "LED_LINK" and "LED_SPEED" of DP83848K
to LED of EtherCAT connector  and "LED_LINK" and "LED_SPEED" of DP83848K
to "pr1_mii0_rxlink" of AM3357?

Best regards,
Kanae

 

  • The RTOS team have been notified. They will respond here.
  • Kanae,

    With the mode 2 of LED_SPEED on DP83848K,
    ON in 100Mb/s
    OFF in 10Mb/s
    which indicates the link will be considered down if connecting the signal to pr1_mii0_rxlink in the 10Mb/s network.

    As I updated in last post of e2e.ti.com/.../2464289, the PHY DP83848x doesn't have 'Fast Link Down Functionality' feature as described in DP83822 and TLK110 datasheet, thus you don't really benefit much (reach to 10us link loss detection) with the PHY DP83848x and pr1_mii0_rxlink/LED_SPEED connection.

    Regards,
    Garrett

  • Hi Garret,

    Thank you for your reply.
    I would like to make sure about your answer.

    If my customer does not care 'Fast Link Down Functionality',
    he just would like to check the active status by LED blinking with MODE 2.
    Can he select mode 2, and can be their board connected as following "Image-1"?

    Or should be their board connected as following "Image-2"?

    Or should my customer select DP83848T instead of DP83848K and "MODE 1" anyway?

    Best regards,
    Kanae

  • Kanae,

    >>Can he select mode 2, and can be their board connected as following "Image-1"?
    Yes.

    >>Or should be their board connected as following "Image-2"?
    No. I am not sure why you need connect LED_SPEED and LED_LINK together.

    >>Or should my customer select DP83848T instead of DP83848K and "MODE 1" anyway?
    Not necessary as 'Image-1' with mode 2 works.

    Regards,
    Garrett
  • Hi Garrett,

    Thank you for your reply!

    I am glad to hear when my customer does not need the fast link down,
    he can select MODE 2 for LED blinking during active.
    My customer design is "Image-1".
    "Image -2" is just confirmation for me.

    May I ask you to check the schematics around the PHY for double check?
    If it is OK, I would like to send it to your email from "+ connect"?

    Best regards,
    kanae
  • Hi Kanae,

    For schematic review, please open another ticket. Our hardware expert will be happy to help you out.

    Thanks,
    Garrett
  • Hi Garret,

    Thank you for your offer to review the schematic.
    However I am not sure how to open anather ticket.
    Can I access "friend ship request" via "+ Connect"?

    Best regards,
    Kanae

  • Kanae,

    I have accepted and replied you with '+connect'.

    Regards,
    Garrett