The Realtek RTL8221B(I)-VM-CG (hereafter referred to as the RTL8221B(I)-VM, except where differences exist) is a highly integrated Ethernet PHY transceiver that is compatible with 10BASE-Te, 100BASE-TX, 1000BASE-T, and 2.5GBASE-T, and is fully compatible with both the IEEE 802.3 standard and the NBASE-T™ Alliance PHY. It provides all the necessary physical layer functions to transmit and receive Ethernet packets over CAT.5e UTP cable.
The RTL8221B(I)-VM provides a MACsec feature of IEEE MAC Security Standard protocol. The integrated functionality with MACsec security engines separate egress and ingress traffic and provides data integrity check, confidentiality and replay protect.
The RTL8221B(I)-VM uses state-of-the-art DSP technology and Analog Front End (AFE) to enable high-speed data transmission and reception over UTP cable. Functions such as Crossover Detection & Auto-Correction, polarity correction, MDI swap, adaptive equalization, cross-talk cancellation, echo cancellation, timing recovery, RFI protection, thermal management, loopback diagnostic capability, and error correction are implemented in the RTL8221B(I)-VM to provide robust transmission and reception capabilities.
Data transfer between MAC and PHY is via the SERDES (Serializer-Deserializer) interface, which supports SGMII, HiSGMII, and 2500Base-X. The RTL8221B(I)-VM operates at various digital I/O voltages, including 3.3V and 1.8V.