🌏🌏🌏 𝐋𝐞𝐭’𝐬 𝐮𝐧𝐜𝐨𝐯𝐞𝐫 𝐭𝐡𝐨𝐬𝐞 𝐌𝐈𝐈 𝐚𝐧𝐝 𝐬𝐢𝐦𝐢𝐥𝐚𝐫 𝐢𝐧𝐭𝐞𝐫𝐟𝐚𝐜𝐞𝐬
𝐌𝐈𝐈, 𝐑𝐌𝐈𝐈 and 𝐒𝐆𝐌𝐈𝐈 are standards for connecting Ethernet Physical Layer Transceivers (PHYs) to Media Access Control (MAC) devices in networking hardware. They define electrical and signalling characteristics for data transmission between MAC and PHY devices.
𝐌𝐈𝐈 (Media Independent Interface): MII connects MAC devices to Fast Ethernet (100 Mbps) PHY devices. It uses a 4-bit data path at 25 MHz, resulting in a 100 Mbps data rate. MII consists of 18 signals, including 4-bit TX data, 4-bit RX data, TX clock, RX clock, and control signals.
𝐑𝐌𝐈𝐈 (Reduced Media Independent Interface): RMII is a reduced pin count version of MII, lowering the number of signals required for connecting Fast Ethernet MAC and PHY devices. RMII uses a 2-bit data path at 50 MHz for both transmitting and receiving data. It reduces the total number of signals to 9, enabling simpler designs and lower-cost implementations.
𝐒𝐆𝐌𝐈𝐈 (Serial Gigabit Media Independent Interface): SGMII connects Gigabit Ethernet (1000 Mbps) MAC and PHY devices. It uses a differential pair for data transmission and another for data reception, operating at a 625 Mbps data rate (with 8B/10B encoding). SGMII supports 10/100 Mbps operation with auto-negotiation, reducing the required signals and enabling lower-cost PCB materials.
𝐑𝐆𝐌𝐈𝐈 (Reduced Gigabit Media Independent Interface): RGMII is for Gigabit Ethernet connections, reducing the number of signals compared to GMII. It uses a 4-bit data path at 125 MHz for transmitting and receiving data, employing 12 signals, including separate transmit and receive clocks.
𝐗𝐆𝐌𝐈𝐈 (10 Gigabit Media Independent Interface): XGMII is for 10 Gigabit Ethernet connections. It uses a 32-bit data path at 156.25 MHz for transmitting and receiving data, resulting in a 10 Gbps data rate.
These interfaces play a vital role in Ethernet networking, providing standardized connections between MAC and PHY devices and ensuring compatibility between devices from different manufacturers.
