About Auto-Negotiation

Can somebody help me ?

Best Regards,
Taka

Hi Ross-san

I'm sorry for the late reply. I really appreciate your response.

I'd like to confirm the following.

Ross Pimentel said:

1)If Auto-Negotiation has failed, How does DP83816 work?

    I think that DP83816 is configured 10Base Half Duplex and NLP are busting.  Is this correct?

You have the DP83816 for 10BASE-T Half-Duplex only for advertisement? What is the capability of your link partner? Is it forced in full-duplex or 100BASE? 10BASE-T Half-Duplex is the lowest setting and should be supported by both devices unless they are configured to not advertise it.

Auto-Negotiation works by the PHY sending out FLP (Fast Link Pulses). These are similar to the 10BASE Link pulses that you can observe on a line. The FLP will contain data and clock information in the bursts to let the link partner know what it is capable of. 

Thank you for your advice. We know such basic knowledge.  We want to know if  Auto-negotiation has failed how DP83816 works.

For example, DP83816 will send out  FLP forever without stopping even if Auto-negotiation become the error?

Ross Pimentel said:

2)Please let me know the conditions to re-start the Auto-Negotiation without Auto-Negotiation Restart function(BMCR Bit9).

If you connect and disconnect the cable the process should restart. If the Auto-Negotiation never completes then there is some other issue going on. Have you verified that the PHY is not in forced mode? Are there any settings you have changed either by software or bootstrapping?

if you connect and disconnect the cable, the user must  re-start the auto negotiation process? Or, it will automatically restart?  (the PHY is not in forced mode) ,

# I think it automatically restart from 3) answer.

Ross Pimentel said:

3)if the cable becomes disconnected, how does DP8316 recognize it?

The device can detect energy link loss. If the cable gets damaged or detached, the device will restart auto-negotiation and try to re-establish a link.

 Also, How long time to be recognized?

Auto-Negotiation can take typically between 2-3 seconds to complete.

I understood this. By the way, if the device detect energy link loss which register shows the error?

Ross Pimentel said:

4) After Auto-Negotiation has failed, Does Auto-BMCRRestart function work by setting BMCR Bit9?

You can restart Auto-Negotiation using that bit. 

 

OK. However, it is necessary for me to confirm an answer to 1).

Best Regards,

Taka