Wiznet MII and SMI Interface


I am attempting to use the WIZ610wi in a design where it will connect to an Ethernet switch over the MII interface. I have not found the documentation on the WIZ610wi to be complete as to this inteface. I have the following questions. I intend to configure the switch for reverse MII mode so that I can connect to the WIZ610wi which I am assuming functions as a MAC.

Does the Wiz610wi MII inteface look like a MAC or a PHY or can it operate as either based on configuration? From the evaluation board schematic it appears as a MAC, but other documentation seems to show otherwise.

In the WIZ610wi datasheet, the MDC signal is listed as an input. This does not make sense if this part acts as a MAC, then the MDC signal needs to be an output so that it can configure the external PHY. The directionality of this signal cannot be determined from the Evaluation board schematic.


Hi jasenharris

We already have reference document about using MII interface.

If you select attachment file, you can download it.
In this example, we connect WIZ610wi to W5300(it is MAC & PHY Ethernet chip).
For the detailed information in order to use MII interface, refer this document.

And this address is address of W5300 datasheet.

Thank you
[AN001]WIZ610wi_to_W5300_Direct_MII_Interface.pdf (40.7 KB)


In the example you gave of the MII connection between the WIZ610wi and the W5300 the MDIO interface is not shown.

  1. Is the MDIO interface needed in this configuration?
  2. The datasheet lists the MDC signal as an input on the WIZ610wi. Shouldn’t this be an output?



MDC/MDIO signals is not MII siganls. So, W5300 have no MDC/MDIO signal.
MDC/MDIO is used on configuration or monitoring of network device.

Typically, MDC/MDIO is controlled by GPIO of Host MCUs. So, WIZ610WI’s MDC is input, not output signal.
I recommend that you don’t use it unless a particular purpose and tied MDC with ground, unconnect MDIO.


What is the address of the WIZ610WI on the MDIO interface?