Introduction - If you have any usage issues, please Google them yourself
The Serial Media Independent Interface, SMMI, is a low pin count version of the MII normally used between ethernet MAC and PHY.
The Serial Media Independent Interface (SMII) is designed to satisfy the following requirements:
Convey complete MII information between a 10/100 PHY and MAC with two pins per port
allow multi port MAC/PHY communications with one system clock
Operate in both half and full duplex
per packet switching between 10 Mbit and 100 Mbit data rates
allow direct MAC to MAC communication