DP83848I: When auto-negotiation is disabled, can detect MDI or MIDX?

Hisao Uchikoshi

Part Number: DP83848I
Other Parts Discussed in Thread: TLK110,

Hi Experts,

When an auto-negotiation is disabled, can DP83848i detect MDI or MIDX? TLK110 or DP83822 seems to be able to detect MDI or MDIX(Auto-MDIX) even when Auto-Negotiation is disabled.

Regards,

Uchikoshi

over 5 years ago

0 Hung Nguyen92 over 5 years ago

TI__Expert 5670 points

Hi Uchikoshi,

As mentioned in the DP83848 datasheet section 6.6.1.2.9, the Auto-MDIX algorithm requires that the Auto-Negotiation Enable bit in the BMCR register to be set. If Auto-Negotiation is not enabled, Auto-MDIX should be disabled as well.

Regards,

Hung Nguyen

0 Hisao Uchikoshi over 5 years ago in reply to Hung Nguyen92

TI__Genius 13530 points

Hi Hung,

Auto-MDIX can be enabled by an external pin as below. Does it still require to set Auto-Negotiation Enable bit to 1?

Regards,

Uchikoshi

0 Hung Nguyen92 over 5 years ago in reply to Hisao Uchikoshi

TI__Expert 5670 points

Hi Uchikoshi,

Yes, the Auto-Negotiation must be enabled when Auto-MDIX is enabled.

Regards,

Hung Nguyen

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DP83848I: When auto-negotiation is disabled, can detect MDI or MIDX?