Introduction
The LU3X54FT is a four-channel, single-chip complete transceiver designed specifically for dual-speed 10Base-T, 100Base-TX, and 100Base-FX repeaters and switches. It supports simultaneous operation in three separate IEEE standard modes: 10Base-T, 100Base-TX, and 100Base-FX.

FEATUREs
10 Mbits/s Transceiver
■ Compatible with IEEE * 802.3 10Base-T standard for twisted-pair cable
■ Autopolarity detection and correction
■ Adjustable squelch level for extended line length capability (two levels)
■ Interfaces with IEEE 802.3u media independent interface (MII) or a serial 10 Mbits/s 7-pin interface
■ On-chip filtering eliminates the need for external filters
■ Half- and full-duplex operations

100 Mbits/s TX Transceiver
■ Compatible with IEEE 802.3u MII (clause 22), PCS (clause 23), PMA (clause 24), autonegotiation (clause 28), and PMD (clause 25) specifications
■ Scrambler/descrambler bypass
■ Encoder/decoder bypass
■ 3-statable MII in 100 Mbits/s mode
■ Selectable carrier sense signal generation (CRS) asserted during either transmission or reception in half duplex (CRS asserted during reception only in full duplex)
■ Selectable MII or 5-bit code group interface
■ Full- or half-duplex operations
■ Optional carrier integrity monitor (CIM)
■ On-chip filtering and adaptive equalization that eliminates the need for external filters