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DP83848K: Link broken possibility if different duplex was selected

Part Number: DP83848K

Hello,

In a system, different company end equipment are connected by Ethernet cable.

One side is DP83848K with 100M full-duplex fixed. On the other side is a PHY with Auto-negotiation mode.

Does the operation become below if 100M half-duplex was selected in result of auto-negotiation?

 1) Link is established between 100M full duplex(DP83848K) and 100M half duplex(a PHY).

 2) Communication is doing some duration.

 3) Link is broken in some reason

We want to know the possibility of link broken when full-duplex PHY and half-duplex PHY are connected.

The customer faces link broken issue as above. The root cause is investigating.

If the root cause is due to different duplex connection, auto negotiation of DP83848K may be a solution.

To consider the possibility, we want to know if link is to progress like above 1) to 3).

Best regards,

Toshihiro Watanabe

  • Hi Toshihiro-san,

    To clarify, you are investigating why the other device may auto-negotiate to half-duplex? Your suggestion is acceptable, put the DP83848 in auto-negotiation and check what mode the devices negotiate to. If you force one device is in full-duplex and the other is in half-duplex, link will be established, but there will be collisions. Both devices should auto-negotiate to the same speed/duplexing.  

    Thank you,

    Nikhil

  • Helo Nikhil-san,

    This issue is investigating what mode the other side mode is to set. Assuming the other side PHY is to se half-duplex mode, we want to know if link broken issue would be occur or not. This information would be helpful for investigating.

    Do we think ok link may be broken due to collision if full-duplex and half-duplex is linked? 

    Best regards,

    Toshihiro Watanabe

  • Hi Toshihiro-san,

    You should be able to establish and maintain link with one device in full-duplex and the other in half-duplex, but will see collisions.

    Thank you,

    Nikhil