DP83867IR: Link delay

Hi Roy,

Could you please expand upon what you mean by TX/RX link delay issue?

Sincerely,

Gerome

Hi Gerome,

We mean that two IC in cascaded, the link time is too long. Please see the waveform. The time duration between DP83867 power on to link stable, it should take 6s. (LED_0) Sometime, it should be longer like 10s. Would you give me some suggestion? Thank you.

Regards,

Roy

Hello Roy,

Just so I can clarify, you have a DP83867 connected to its link partner, and the issue is that you are stating that it takes 10s to link up? Is this correct?

Sincerely,

Gerome

Hi Gerome,

Correct.

Roy

Hi Roy,

What is the link partner for this DUT? Can you try other link partners (other PHYs, a PC, etc) and see what the link up time is for those?

What are you expectations for link up time?

Sincerely,

Gerome

Hi Gerome,

What is the link partner for this DUT? Can you try other link partners (other PHYs, a PC, etc) and see what the link up time is for those?

We did the below two experiment,

1. Cascade three  DP83867(Use three PCBA cascaded) :  

We didn't power off the 1st stage(DP83867_1)'s power and let both of 2nd and 3rd stage's power turn on at the same time. We found that the 2nd and 3rd link time was long. But if we let 2nd and 3rd stage power didn't turn on at the same time, the link time was shorter. It's around 4s. But in our application, we need turn on both of 2nd and 3rd stage power turn on at the same time.d

2. Change the 2nd PHY to another vendor's PHY, the action was same as above(2nd and 3rd stage power turn on at the same time). The link time was around 4s.

What are you expectations for link up time?

We hope the link time under 4s.

Regards,

Roy

Hi Roy,

I dont necessarily understand the setup. How are PHY 1, 2, and 3 connected to each other? Through MDI?

Understand that link is 4s expected, but you are reporting 10s linkup time in unexpected case, correct?

Sincerely,

Gerome