DP83TC814S-Q1: About the linkup time

Hello,

Thank you for your query. One of our team members will be assisting you shortly.

Sincerely,

Gerome

Hello Gerome,

Could your team members give me the answer today?

I need to know this information urgently。

Best Regards!

Wang

Hi Wang,

SNLA389 describes the procedure to measure link up time. It is recommended to give an indicator via IO state when the last register has been written. Time can then be measured between this point and the point where link status goes high (register 0x1[2] is polled or LED_0 status is monitored).

Thanks,

David

Hi David,

In below E2E, I discussed with other colleagues in your team,  LED_0 had delayed.

Your team suggested us to measure the TRD_P/M.

So I don't we will follow which method.

Best Regards!

Wang

Hi Wang,

There should not be any delay in LED_0 as link status.

Jingkun Wang said:

Can you please share this same scope shot, but this time with LED_0 monitored as well.

For start of link up time, LED_1 can be driven LOW to indicate the completion of the initialization script. Please add one register after the last 0x1F=0x4000 register write in the initialization script to force LED_1 pin LOW. 0x451 bit[4] = 0 and bit[5] = 1. 

Thanks,

David

Hello David,

David Creger said:

Can you please share this same scope shot, but this time with LED_0 monitored as well.

Below adding the LED_0 in the waveform.

The pink waveform indicates the last ox1F=0x4000 register write in the initialization script.

Best Regards!

Wang

Hi Wang,

Got it, thank you for the update. I see link up time is about 16ms now (time between pink and green rising edges), well within the IEEE specification. Will this satisfy your requirements?

Thanks,

David

Hello David,

At this condition, the linkup time is meet IEEE specification.

It has some delay than TRD_P/M.

Does it use LED_0 for linkup indication?

Best Regards!

Wang