RTL8125BG(S)-CG

General Description

The Realtek RTL8125BG/RTL8125BGS 10/100/1000M/2.5G Ethernet controller combines a four-speed IEEE 802.3 compatible Media Access Controller (MAC) with a four-speed Ethernet transceiver, PCI Express bus controller, and embedded memory. With state-of-the-art DSP technology and mixed-mode signal technology, the RTL8125BG/RTL8125BGS offers high-speed transmission over CAT 5e UTP cable or CAT 3 UTP (10Mbps only) cable. Functions such as Crossover Detection and Auto-Correction, polarity correction, adaptive equalization, cross-talk cancellation, echo cancellation, timing recovery, and error correction are implemented to provide robust transmission and reception capability at high speeds. The RTL8125BGS provides a built-in switching regulator.

The RTL8125BG/RTL8125BGS supports the PCI Express 2.1 bus interface for host communications with power management, and is compatible with the IEEE 802.3u specification for 10/100Mbps Ethernet, the IEEE 802.3ab specification for 1000Mbps Ethernet and the IEEE 802.3bz specification for 2500Mbps Ethernet. It supports an auxiliary power auto-detect function and will auto-configure related bits of the PCI power management registers in PCI configuration space.

Advanced Configuration Power management Interface (ACPI)—power management for modern operating systems that are capable of Operating System-directed Power Management (OSPM)—is supported to achieve the most efficient power management possible. PCI MSI (Message Signaled Interrupt) and MSI-X are also supported.

In addition to the ACPI feature, remote wake-up (including AMD Magic Packet and Microsoft Wake-Up Frame) is supported in both ACPI and APM (Advanced Power Management) environments. To support WOL from a deep power down state (e.g., D3cold, i.e., main power is off and only auxiliary exists), the auxiliary power source must be able to provide the needed power for the RTL8125BG/RTL8125BGS. To further reduce power consumption, the RTL8125BG/RTL8125BGS also supports PCIe L1 substate L1.1 and L1.2.

The RTL8125BG/RTL8125BGS supports ‘RealWoW!’ technology that enables remote wake-up of a sleeping PC through the Internet. This feature allows PCs to reduce power consumption by remaining in low power sleeping state until needed.

Note: The ‘RealWoW!’ service requires registration on first time use.

The RTL8125BG/RTL8125BGS supports Protocol offload. It offloads some of the most common protocols to NIC hardware in order to prevent spurious Wake-Up and further reduce power consumption. The RTL8125BG/RTL8125BGS can offload ARP (IPv4) and NS (IPv6) protocols while in the D3 power saving state.

The RTL8125BG/RTL8125BGS supports the ECMA (European Computer Manufacturers Association) proxy for sleeping hosts standard. The standard specifies maintenance of network connectivity and presence via proxies in order to extend the sleep duration of higher-powered hosts. It handles some network tasks on behalf of the host, allowing the host to remain in sleep mode for longer periods. Required and optional behavior of an operating proxy includes generating reply packets, ignoring packets, and waking the host.

The RTL8125BG/RTL8125BGS supports IEEE 1588, IEEE 1588-2008, and IEEE 802.1AS, also known as Precision Time Protocol (PTP). IEEE 802.1AS is part of the Ethernet AVB (Audio Video Bridging) standard. PTP provides micro-second level accuracy time synchronization among multiple Ethernet devices. The RTL8125BG/RTL8125BGS implements hardware support for these standards. The RTL8125BG/RTL8125BGS supports IEEE 802.1Qav, also part of the Ethernet AVB standard. IEEE 802.1Qav is a forwarding and queuing mechanism enhancement. It provides guarantees for time-sensitive (i.e., bounded latency and delivery variation), loss-sensitive real-time audio video (AV) data traffic transmissions.

The RTL8125BG/RTL8125BGS supports IEEE 802.3az-2010, also known as Energy Efficient Ethernet (EEE). IEEE 802.3az-2010 operates with the IEEE 802.3 Media Access Control (MAC) Sublayer to support operation in Low Power Idle mode. When the Ethernet network is in low link utilization, EEE allows systems on both sides of the link to save power.

The RTL8125BG/RTL8125BGS is compatible with Microsoft NDIS5, NDIS6 (IPv4, IPv6, TCP, UDP) Checksum and Segmentation Task-offload (Large send and Giant send) features, and supports IEEE 802.1P Layer 2 priority encoding and IEEE 802.1Q Virtual bridged Local Area Network (VLAN) and IEEE 802.1ad Double VLAN. The above features contribute to lowering CPU utilization, especially benefiting performance when in operation on a network server.

The RTL8125BG/RTL8125BGS supports Receive-Side Scaling (RSS) to hash incoming TCP connections and load-balance received data processing across multiple CPUs. RSS improves the number of transactions per second and number of connections per second, for increased network throughput.

The maximum supported jumbo frame length of the RTL8125BG/RTL8125BGS is 16384 bytes

The device features inter-connect PCI Express technology. PCI Express is a high-bandwidth, low-pin-count, serial, interconnect technology that offers significant improvements in performance over conventional PCI and also maintains software compatibility with existing PCI infrastructure.

The RTL8125BG/RTL8125BGS is suitable for multiple market segments and emerging applications, such as desktop, mobile, workstation, server, communications platforms, and embedded applications.