Description
The DNC3X3425 is a twisted-pair transceiver macrocell that supports transmission and reception over category 3 unshielded twisted-pair (UTP) cable and category 5 UTP.
The DNC3X3425 has been designed specifically for applications that support both 10Base-T and 100Base-X, such as network interface cards (NICs) and switches.

FEATUREs
General
■ Ports individually configurable
■ Autonegotiation and management:
    — Fast link pulse (FLP) burst generator.
    — Arbitration function.
    — Accepts preamble suppression.
    — Operates up to 12.5 MHz.
■ Supports the MII station management protocol and frame format (clause 22): basic and extended register set.
■ Supports next page.
■ Provides status signals: receive activity, transmit activity, full duplex, collision/jabber, link integrity, and speed indication.
■ Powerdown mode for 10 Mbits/s and 100 Mbits/s operation.
■ Loopback testing for 10 Mbits/s and 100 Mbits/s operation.
■ 0.25 µm low-power CMOS technology.
■ Single 3.3 V power supply operation.
■ 25 MHz XTAL oscillator input or 25 MHz/50 MHz/ 125 MHz clock input.
■ Compatible with RMII (standard version) and SMII (standard version).

Quad 10 Mbits/s Transceiver
■ DSP based.
■ Compatible with IEEE * 802.3 10Base-T standard for twisted-pair cable.
■ Half- and full-duplex operations.
■ Autopolarity detection and correction.
■ Adjustable squelch level for extended wire-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.

Quad 100 Mbits/s Transceiver
■ Compatible with IEEE 802.3u MII (clause 22), PCS/PMA (clause 24), PMD (clause 25), MII management, and autonegotiation (clause 28) specifications.
■ Selectable 5-bit code-group (PDT/PDR interface) or 4-bit data nibbles (MII interface) I/O.
■ Full- or half-duplex operations.
■ Optional carrier integrity monitor (CIM).
■ Selectable carrier sense signal generation (MCRS) asserted during either transmission or reception in half duplex (MCRS asserted during reception only in full duplex).
■ Adaptive equalization and baseline wander correction.
■ On-chip filtering eliminates the need for external filters.

Quad 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.
■ Fiber mode automatically configures port:
    — FX mode enable is pin or register selectable
    — Disables autonegotiation and 10Base-T.
    — Enables 100Base-FX remote fault signaling.
    — Disables MLT-3 encoder/decoder.
    — Disables scrambler/descrambler.