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

Alvaro GM

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!

over 5 years ago

0 Geet Modi over 5 years ago

TI__Mastermind 26320 points

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

0 Alvaro GM over 5 years ago in reply to Geet Modi

Prodigy 120 points

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

0 Geet Modi over 5 years ago in reply to Alvaro GM

TI__Mastermind 26320 points

Yes, suggest using BMSR in combination with BMCR.

Regards,
Geet

Interface

Interface forum

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