SM100GMA-05 Copper Small Form Pluggable
(SFP) transceivers are based on the SFP Multi Source Agreement (MSA).
They are compatible with the Gigabit Ethernet and 1000BASE-T standards
as specified in IEEE Std 802.3 . The 1000BASE-T physical layer IC (PHY)
can be accessed via I2C, allowing access to all PHY settings and features.
The 1000BASE-T uses the SFP's RX_LOS pin for link indication. If pull up
SFP's TX_DISABLE pin, PHY IC be reset..