The KSZ8081 is a single-supply 10Base-T/100Base-TX Ethernet physical-layer transceiver for transmission and reception of data over standard CAT-5 unshielded twisted pair (UTP) cable. The KSZ8081 is a highly-integrated PHY solution.

Ethernet transceiver
MII interface support (KSZ8081MNX)
RMII v1.2 Interface support with a 50MHz reference clock output to MAC, and an option to input a 50MHz reference clock (KSZ8081RNB)
RMII back-to-back mode support for a 100Mbps copper repeater
MDC/MDIO management interface for PHY register configuration
Programmable interrupt output
LED outputs for link and activity status indication
On-chip termination resistors for the differential pairs
Baseline wander correction
HP Auto MDI/MDI-X to reliably detect and correct straight-through and crossover cable connections with disable and enable option
Auto-negotiation to automatically select the highest linkup speed (10/100Mbps) and duplex (half/full)