3.4.1.1 Ethernet 10/100 Interface

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

The KSZ8081RNA is connected over the Reduced Media Independent Interface (RMII) directly to the RMII-compliant MAC inside the SAMA7G5 MPU. As the power-up default, the KSZ8081RNA uses a 25 MHz MEMS oscillator to generate all required clocks, including the 50-MHz RMII reference clock output for the MAC.

For more information about the KSZ8081RNx, refer to the product web page.

An indiviual unique 48-bit MAC address (Ethernet hardware address) is allocated to this product and is stored in one of the Microchip 24AA025E48 TWI serial EEPROMs described in Dual Serial EEPROM.

Additionally, for monitoring and control purposes, the RJ45 connectors feature a LED functionality to indicate activity, link, and speed status.