DP83822IF: Link loss detection

Hirotaka Matsumoto

Part Number: DP83822IF

Hi all

Would you mind if we ask DP83822IF?
We have some questions about link loss detection.

<Question1>
On the phy side, how does phy detect Link loss?
During 250us, there is no transmition amongs phys, does the phy detect Link loss?
Or, does it include Low Quality Data / Link Loss condtion?
And then, when Link Loss Recovery is normal mode, correct data communication consists during 250us, is there no Link Loss condtion?

<Question2>
Between PHY and MAC(CPU), what is the best way to detect link loss?
To read register? or LED(LINK) port connects to CPU interrupt port?
Kind regards,

Hirotaka Matsumoto

over 7 years ago

0 Aniruddha Khadye over 7 years ago

TI__Mastermind 18425 points

Hello Matsumoto-san,

If less 250us link loss time is required then DP83822 supports Fast Link Down feature. DP83822 can then enable link down based on multiple criteria like RX error count, energy loss etc. These parameters can be controlled individually. More information can be found in the Fast Link Down Functionality section of the datasheet.

Connecting Link LED to CPU interrupt port is a better idea. If link loss is detected through register access then the CPU will have to continuously poll the link status bit of the PHY. This will add a lot of overhead on the CPU.

-Regards,
Aniruddha

0 Hirotaka Matsumoto over 7 years ago in reply to Aniruddha Khadye

Guru 27585 points

Aniruddha san

Thank you for your reply!

We could understand about Fast link loss detection.

The things which we would like to know are Link loss detections in case of normal(250us).
Is the detection condition the same as Fast link detection?
When detection time is 250us, is our recognition correct?
-RX Error Count
-MLT3 Error Count
-Low SNR Threshold
-Signal/Energy Loss

We need your help.

Kind regards,

Hirotaka Matsumoto

0 Hirotaka Matsumoto over 7 years ago in reply to Hirotaka Matsumoto

Guru 27585 points

Aniruddha san

We are sorry to rush you, however could you give us the reply?

Kind regards,

Hirotaka Matsumoto

0 Hirotaka Matsumoto over 7 years ago in reply to Aniruddha Khadye

Guru 27585 points

Aniruddha san

We guess that your days are so busy, however could you give us the reply?

Kind regards,

Hirotaka Matsumoto

0 Hirotaka Matsumoto over 7 years ago in reply to Aniruddha Khadye

Guru 27585 points

Aniruddha san

Could you let us know your circumstance?
We apologize that we don't have enough knowledge about link down.
Our question is relation to IEEE802.3, otherwise, it is not relation to the device.

We appreciate your help always.

Kind regards,

Hirotaka Matsumoto

0 Aniruddha Khadye over 7 years ago in reply to Hirotaka Matsumoto

TI__Mastermind 18425 points

Hello Matsumoto-san,

Yes, normal link loss will be approximately 250us but this is not parameter listed in the Timing section of the datasheet. This number should be used as a guideline.

-Regards,
Aniruddha

0 Hirotaka Matsumoto over 7 years ago in reply to Aniruddha Khadye

Guru 27585 points

Aniruddha san

Thank you for your reply!

Kind regards,

Hirotaka Matsumoto

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DP83822IF: Link loss detection