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What is MDIO used for?
Management Data Input/Output, or MDIO, is a 2-wire serial bus that is used to manage PHYs or physical layer devices in media access controllers (MACs) in Gigabit Ethernet equipment.
What is MDC and MDIO?
• MDC (Management Data Clock) sourced continuously from STA (station. management entity) • MDIO (Management Data Input/Output)
What is PHY address?
This is an identifier that tells you which of the physical PHYs were used to interface to the network. The numbers range from 0 – 31 and change, depending on whether or not you specified a specific PHY or if you let the driver select the default (which varies from card to card).
How many registers can a MDIO bus access?
The Management Data Input/output (MDIO) is a serial bus defined for the Ethernet family of IEEE 802.3 standards for the Media Independent Interface. MDIO was defined in Clause 22 of IEEE 802.3; a MDIO bus is able to access up to 32 registers in 32 different PHY devices.
How is the MDIO interface implemented in a Mac?
The MDIO interface is implemented by two signals: MDC clock: driven by the MAC device to the PHY. MDIO data: bidirectional, the PHY drives it to provide register data at the end of a read operation.
What kind of resistor do I need for MDIO?
The MDIO requires a specific pull-up resistor of 1.5 kΩ to 10 kΩ, taking into account the total worst-case leakage current of 32 PHYs and one MAC. Before a register access, PHY devices generally require a preamble of 32 ones to be sent by the MAC on the MDIO line. The access consists of 16 control bits, followed by 16 data bits.
How many PHY slaves can a Mac bus support?
MDIO Interface Clock (MDC): clock driven by the MAC device to the PHY. MDIO data: bidirectional, the PHY drives it to provide register data at the end of a read operation. The bus only supports a single MAC as the master, and can have up to 32 PHY slaves.