TMDS243EVM: Is there a problem if MII0_RXLINK signal is not configured?

Hi Hongkai,

For EtherCAT, MII0_RXLINK is necessary to support features like Fast link up and Rx error detection. If this is not enabled, the MDIO state machine-based detection is implemented, which is slow due to a serial link for messaging from the MDIO controller to the PHYs, which typically takes from 200 to 250 µs. MLINK/MII0_RXLINK detection occurs as fast as the PHY can toggle the link and typically within 10 µs.

Apart from this, the EtherCAT functionality won't be affected due to the absence of this signal. 

It is important to have this feature enabled, so recommend to choose a PHY which supports this.

Regards,
Aaron