Product Description
The Intel® 82551ER Integrated 10BASE-T/100BASE-TX Ethernet Controller expands the family of
Intel® 8255x controllers. As part of Intel’s fourth generation of fully integrated Fast Ethernet
MAC/PHY solutions, the 82551ER is optimized for low-cost, embedded applications.
The 82551ER provides excellent performance with offloading of TCP, UDP and IP checksums. Its
optimized 32-bit interface and efficient scatter-gather bus mastering capabilities enable the controller
to perform high-speed data transfers over the PCI bus. These capabilities accelerate the processing of
high-level commands and operations, lowering CPU utilization. The device’s architecture enables
efficient data flow from the bus interface unit to the 3KB transmit and receive FIFOs, providing the
perfect balance between the wire and system bus. In addition, multiple priority queues augment
Quality of Service (QoS) performance.
The 82551ER is pin-compatible with the Intel® 82559ER Fast Ethernet controller, and it is layoutcompatible
with Intel® 82540 Gigabit Ethernet controller. Intel-supported 82551ER drivers run on
the standard Intel® 82551QM Fast Ethernet PCI/CardBus Controller, providing OEMs an upgrade
path to the 82551QM for additional features and increased functionality.

Applications
The Intel 82551ER Integrated 10BASE-T/100BASE-TX Ethernet Controller is designed for use in
the following applications:
Information appliances, set-top boxes
Point-of-Sales terminals, Web kiosks
Printers
Other embedded applications