DP83TC811R-Q1: Polarity change

Hello,

The interrupt register should work. Please note that all detection and correction is on the slave PHY. Is this value being read on master or slave PHY?

Sincerely,

Gerome

Hello Gerome,

thank you for the answer. Normally it is a slave and we see the bit flagged on every start up of the PHY, if polarity flipped or not. After reading out flag is always cleared, but never reflagged after flipping again. Is there something which we have to consider?

Hello,

How are you flipping the polarity? Is the cable plugged in upon startup, or are you plugging and flipping after poweron?

Sincerely,

Gerome

Hello Gerome,

i tried both, flipping the polarity before startup and also after startup. There is always the same behaviour, it doesn't change the Polarity Interrupt Bit (Bit 9). I did also Polarity Change Interrupt Enable (Bit 1). But there is also nothing changing.

Kind Regards

Ekrem

Hello,

I will need to test this in lab. I will try to get conclusive results by next Wednesday, but please know that there might be a chance this might come after Thanksgiving due to short week in US.

Sincerely,

Gerome

Hello,

We were able to test this in lab and validate your findings of incorrect status bits. However, the polarity correction and auto-detection are proven to be working as link is up no-matter the polarity of the cable. Can we ask why it is important to understand when polarity is incorrect if the correction and detection are automatically taken care of?

Sincerely,

Gerome

Hello Gerome,

thank you for testing and validating my results. It is important for us because our customer wants an error/warning message if the polarity is wrong. That is one of the requirements. It is important because of to know if it is correct connected or not. Can we have a bugfix for that?

Best Regards

Ekrem

Hi Ekrem,

What do they plan on doing with this message if the PHY automatically correct for this and gets link up?

Sincerely,

Gerome

Hi Gerome,

they always want to be sure, that polarity is always the same and don't need to be flipped.

Best Regards

Ekrem

Hello,

I am still unsure of the purpose of wanting to be sure if this is automatically corrected for during linkup. Why is this needed if this link is established no matter the polarity?

Sincerely,

Gerome

Hi Gerome,

we will clarify this with our customer. Btw, what is the reason you implemented this feature?

Best Regards

Ekrem

Hi Ekrem,

This feature is an optional feature in IEEE802.3 spec.

Sincerely,

Gerome