The Intel® 82540EM Gigabit Ethernet Controller is a single, compact component with integrated Gigabit Ethernet MAC and PHY layer functions. Packaged in a 15x15 mm TFBGA, the Intel 82540EM Gigabit Ethernet controller is footprint compatible with the Intel® 82551QM and 82551ER Fast Ethernet Controllers (same package size, same number and pattern of pins and similar signal layout), allowing for a flexible, Gigabit Ethernet or 10/100 Ethernet design.
The Intel 82540EM integrates Intel's fourth generation Gigabit MAC design with fully integrated, physical-layer circuitry to provide a standard IEEE 802.3 Ethernet interface for 1000Base-T, 100Base-TX, and 10Base-T applications (802.3, 802.3u, 802.3ab). The controller is capable of transmitting and receiving data at 1000 Mb/s, 100 Mb/s, or 10 Mb/s data rates. In addition, the controller provides a direct Peripheral Component Interconnect (PCI) 2.2 compliant bus up to 66 MHz.
The Intel 82540EM's on-board SMBus port enables enhanced manageability and system health monitoring via the LAN. With SMBus, management packets can be routed to or from a management processor. The SMBus port enables industry standards such as IPMI (Intelligent Platform Management Interface) to be implemented with the 82540EM. In addition, ASF 1.0 (Alert Standard Format) circuitry provides alerting and remote control capabilities with standardized interfaces.
The Intel 82540EM Gigabit Ethernet Controller architecture is optimized to deliver both high performance and PCI bus efficiency with the lowest power and smallest die size. Using state logic design with a pipelined DMA Unit and 128 bit wide buses for the fastest performance, the Intel 82540EM controller handles Gigabit Ethernet traffic with low network latency and minimal internal processing overhead. The controller's architecture includes independent transmit and receive queues to limit PCI bus traffic, and a PCI interface that maximizes the use of bursts for efficient bus usage. The Intel 82540EM Gigabit Ethernet Controller prefetches up to 64 packet descriptors in a single burst for efficient PCI-bandwidth usage. A 64 KB on-chip packet buffers maintain superior performance as available PCI bandwidth changes. Advanced interrupt moderation hardware manages interrupts generated by the Intel 82540EM controller to further improve system efficiency. In addition, using hardware acceleration, the controller also offloads tasks from the host processor, such as TCP/UDP/ IP checksum calculations and TCP segmentation.