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DP83620: BMSR_ANEGCAPABLE is set to 1 even when configured on fibre mode

Part Number: DP83620

BMSR register value is 111100011001101 even when using FX mode, which doesn't allow auto negotiation. Note however that bit 3, AUTO-NEGOTIATION ABILITY appears a 1, so typical drivers aren't able to use this information to disable autonegotiation.

I'm thinking of using alternatively bit 12 of BMCR, AUTO-NEGOTIATION ENABLE to check strap initial value al rest, but this doesn't seem like the proper way to do it. Any suggestions?

Thanks!

  • 12 AUTO-NEGOTIATION Strap, RW Auto-Negotiation Enable:
    ENABLE Strap controls initial value at reset.

    If FX is enabled (FX_EN = 1), then this bit will be reset to 0.
    1 = Auto-Negotiation Enabled - bits 8 and 13 of this register are ignored when this bit is
    set.
    0 = Auto-Negotiation Disabled - bits 8 and 13 determine the port speed and duplex
    mode.


    Regards,
    Geet
  • In reply to Geet Modi:

    Hi,

    So, am I right in the understanding that querying BMSR(3) AUTO-NEGOTIATION ABILITY is futile, because it'll always read as 1, regardless of the bootstrap resistors I set to configure fiber vs cable?

    Thanks
  • In reply to Alvaro Gamez:

    Yes, suggest using BMSR in combination with BMCR.

    Regards,
    Geet

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