Is MDIO address 0 a valid address, or must a second PHY be strapped to 7 and why?

Is the MDIO address 0 workable or not. The recommendation in the datasheet that suggests using address 7 does not elaborate.

The Apalis IMX8X datasheet recommends MDIO address 7 for the second Ethernet as below, but the datasheet does not explain why. The PHY is currently defaulted to address 0 when not strapped to a particular address, is address 0 ok, or does it need to be strapped to 7 to work and why (i.e. is there anything special about address 0 where it should not be used for the second phy?)

The Apalis IMX8X datasheet explains: The MDIO configuration port signals are shared between the on-module and external Ethernet PHY. It is crucial to make sure that the two PHYs are not strapped to the same address. The MDIO interface of the Ethernet PHY on the module is using the address 00100. We recommend using the address 00111 for the external PHY.

Yes MDIO address 0 is a valid address.

You can choose any MDIO address except 4 for Apalis iMX8X. This ticket is answered.