General Description
The KSZ8081RNA 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 KSZ8081RNA is a highly-integrated  PHY solution. It reduces board cost and simplifies board layout by using on chip termination resistors for the differential pairs  and  by integrating a low-noise regulator to supply the 1.2V core, and by offering 1.8/2.5/3.3V digital I/O interface support.

FEATUREs
•  Single-chip 10Base-T/100Base-TX IEEE 802.3
compliant Ethernet transceiver
•  RMII v1.2 Interface support with a 50MHz reference clock output to MAC, and an option to input a 50MHz reference clock
•  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 link up speed (10/100Mbps) and duplex (half/full)
•  Power-down and power-saving modes
•  LinkMD TDR-based cable diagnostics to identify faulty copper cabling
•  Parametric NAND Tree support for fault detection between chip I/Os and the board