DP83867IR: 100BASE full duplex fixed mode communication failure

Kazuki Itoh

Part Number: DP83867IR

Hi team,

DP83867IR doesn’t link up correctly with certain systems with the 100BASE full duplex fixed mode which registers are set below:

Address 0x0009：0x0000
1000BASE-T Full/Half set to OFF
Address 0x0012：0x6400
Interrupt setting

Address 0x0000：0x2100
100Mbps fixed, auto negotiation set to OFF
Address 0x0086：0x0073
TX/RX delay setting
Address 0x0018：0x6B50
LED2 setting
Address 0x012C：0x0E81
datasheet recommendation to improve the short cable performance

Could you help me to address this issue?

Note: #1 and #3 are the specific settings for 100BASE full duplex fixed mode.

When AUTO-NEGOTIATION mode, it works correctly.

Regards,

Itoh

over 3 years ago

0 Gerome Cacho over 3 years ago

TI__Mastermind 39785 points

Hello,

Thank you for your query. The US offices are closed for Labor Day. We expect to take a look at your query when offices open Tuesday, 9/6/22.

Sincerely,

Gerome

0 Kazuki Itoh over 3 years ago in reply to Gerome Cacho

TI__Genius 10730 points

Hi Gerome-san,

Let me follow-up with you on this qeuery.

Could you support me to address this issue?

Regards,

Itoh

+1 Gerome Cacho over 3 years ago in reply to Kazuki Itoh

TI__Mastermind 39785 points

Hi Itoh-san,

It appears that you are forcing MDI communication in 100Base-Tx. If that is the case, the other PHY MUST be forced to the same settings (speed, MDI, duplex, etc.) or atleast have advertisement for those settings. Else, the PHYs will not link up.

Sincerely,

Gerome

0 Kazuki Itoh over 3 years ago in reply to Gerome Cacho

TI__Genius 10730 points

Hi Gerome-san,

Yes, my cusmer is trying to force MDI communication in 100Base-Tx.

OK, my customer says they'll check the other PHY setting.

Do you think DP83867IR setting is good and no additional setting is needed to link up?

Regards,

Itoh

+1 Gerome Cacho over 3 years ago in reply to Kazuki Itoh

TI__Mastermind 39785 points

Hello,

It would be more ideal if you were to auto-negotiate/advertise instead of force speed, but current settings shared look okay.

Sincerely,

Gerome

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DP83867IR: 100BASE full duplex fixed mode communication failure