Introduction
Configuration
The LU3X54FTL 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. The LU3X54FTL provides a 3.3 V or 5.0 V MII interface logic level.

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

100 Mbits/s FX Transceiver
■ Compatible with IEEE 802.3U 100Base-FX standard
■ Reuses existing twisted-pair I/O pins for compatible fiber-optic transceiver pseudo-ECL (PECL) data:
    — No additional data pins required
    — Reuses existing LU3X54FTL pins for fiber-optic signal detect (FOSD) inputs
■ Fiber mode automatically configures port:
    — Disables autonegotiation
    — Disables 10Base-T
    — Enables 100Base-FX remote fault signaling
    — Disables MLT-3 encoder/decoder
    — Disables scrambler/descrambler
■ FX mode enable is pin- or register-selectable on an individual per-port basis