DP83822I: Cable failure

Hi Team,

If TD_P and TD_M of the PHY and RD_P and RD_M of the PHY are shorted, our PHY will have a protection circuit internally and the link between the PHY will drop.

--

Regards,

Hillman Lin

Hi Hillman-san,

Thank you for your reply.

Do you mean it need to enable TDR Auto-Run as cable diagnostics?

If there are other protection circuit please let me know.

Hi Atsushi-san,

TDR is the diagnostic tool that will run to determine if the cable is shorted. 

This is the feature I am mentioning about.

--

Regards,

Hillman Lin

Hi Hillman-san,

TDR has manual mode and automatic mode.

Will the protection circuit not work if automatic mode is disable at CR1 Bit[8]?

Hi Hillman-san,

I would like to know more about the following.
Is this mentioned in the datasheet or application note?
If yes, please let me know where it is described.

"In the normal condition when TD is shorted with RD, the PHY is basically outputting the signal directly to receiver. our PHY also support that as external feature."

Hi Atsushi-san,

This should be in the "external loopback" session in the datasheet.

--

Regards,

Hillman Lin

Hi Hillman-san,

Thank you for your reply.
Where is the following mentioned in the datasheet or application note?

"Our PHY will link drop and protect the signal internally if MDI lines is short to ground. It will have a link down if MDI lines is connected to round. Internal circuit is not sharable externally."

And I'm sorry for my poor ability of understanding.
I would like to know not how to diagnose short or open, but whether the protection function works as a PHY behavior when a sudden short between TD and RD at cable occurs to avoid failure.
I expect this protection function described in a document.