The DP83561-SP supports the 100BASE-TX standard as defined by the IEEE 802.3 standard. In 100M mode, the PHY will use two MDI channels for communication. The 100BASE-TX can work in Auto-Negotiation mode or in force mode. The PHY can be configured in 100BASE-TX through the register settings or strap settings. When using DP83561-SP in force 100Base-TX mode, it is required to enable Robust Auto-MDIX feature from register 0x1E.