DP83822I: Registers 0x0180 to 0x0184 at TDR function

Hi Hillman-san,

Thank you for your reply.

I read this document but there is no description about how to calculate and think when multiple peaks were observed.

Could you give me some advice?

Hi Atsushi-san,

Thank you for pointing it out. Here is the TDR app note for DP83826PHY which have a better explanation on why do we need multiple peaks. Hopefully this would clear up your confusion. We will also edit the DP83822PHY's TDR appnote to give a better explanation.

https://www.ti.com/lit/an/snla428/snla428.pdf?ts=1703006146774&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FDP83826E

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Regards,

Hillman Lin

Hi Hillman-san,

Because the DP83826 and DP83822I have different register specifications, it was difficult to understand how to calculate in case of multiple peaks from this application note.

If multiple peak values are stored, is it necessary to use all values in calculations?

Is it not recommended to use only the first peak(Location 1) even if multiple peaks are stored and calculate according to [2.3.2 Cable Length and Fault Location] in the following application report?

https://www.ti.com/lit/an/snla253/snla253.pdf

Hi Atsushi-san,

Are you not able to get the accurate result for TDR after using 0x180 to 0x184 for calculation. If so, could you give me an example on the calculation?

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Regards,

Hillman lin

Hi Hillman-san,

I’m sorry, the customer doesn't calculate yet because they don't know how to do.

I have additional questions.

1) Why are there five peak stored registers not one?

2) Even if multiple peaks are stored, is it okay to use only one(Location 1) for calculation?

Hi Atsushi-san,

I will discuss with the team to provide you more detail information.

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Regards,

Hillman Lin