10/100/1000 BASE-T Copper Small Form Pluggable (SFP) transceivers are based on the SFP Multi Source Agreement (MSA) . They are compatible with the Gigabit Ethernet standards as specified in IEEE Std 802.3. The 10/100/1000 BASE-T physical layer IC (PHY) can be accessed via I2C, allowing access to all PHY settings and features. The XGSF-T12-02-4 is compatible with 1000BASE-X auto-negotiation and have a link indication feature. PHY is disabled when TX disable is high or open.