What is MDC and MDIO?
What is MDC and MDIO?
The MDIO interface is implemented by two signals: 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.
What is MDIO interface?
The MDIO Interface component supports the Management Data Input/Output, which is a serial bus defined for the Ethernet family of IEEE 802.3 standards for the Media Independent Interface (MII). The MII connects Media Access Control (MAC) devices with Ethernet physical layer (PHY) circuits.
Is MDIO the same as I2C?
MDIO – A short history For most pluggable optical transceivers the interface used for monitor and control is the I2C interface. Defined as part of MII in IEEE802. MDIO works with 1.2V supply with a clock rate of 4MHz (downward compatibility to 100 kHz).
What is MDIO register?
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. The management of these PHYs is based on the access and modification of their various registers.
Is MDIO open drain?
The MDIO bus is not open-drain, when a device transmits data, the pin will change to push-pull output. So yes, it can cause damage, but as the outputs will not be constantly driving the pins to opposite logic states, there is less likely to be damage.
What is MII and RMII?
MII vs RMII for Ethernet Therefore, RMII (reduced MII) was developed as a variant of MII to cut the number of unshareable signals per PHY interface in half (down to 8 per PHY). The RMII specification is also capable of supporting 10 Mbps and 100 Mbps data rates, and there are gigabit-capable variants.
Is Mdio open drain?
Does MDC need pull up?
MDC is unidirectional and push pull – > Input side of the LSF doesnt need pullup resistor. Output side will need pullup resistor. TXS0102 can support both without the need for pullup resistor on either input or output side.
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).
What is Ethernet RMII?
The serial gigabit media-independent interface (SGMII) is a variant of MII used for Gigabit Ethernet but can also carry 10/100 Mbit/s Ethernet. It uses differential pairs at 625 MHz clock frequency DDR for TX and RX data and TX and RX clocks. It differs from GMII by its low-power and low pin-count 8b/10b-coded SerDes.
What is the basic frame format of MDIO communication?
Clause 22 defines the MDIO communication basic frame format (figure 13) which is composed of the following elements: Figure 13: Basic MDIO Frame Format. The frame format only allows a 5-bit number for both the PHY address and the register address, which limits the number of MMDs that the STA can interface.
How many opcodes are there in the MDIO header?
The first field in the MDIO header is the Preamble. During the preamble, the MAC sends 32 bits, all ‘1’, on the MDIO line. The Start field consists of 2 bits and always contains the combination ’01’. The Opcode consists of 2 bits. There are two possible opcodes, read ’10’ or write ’01’.
What is the use of MDIO interface in Ethernet?
A Data interface to the Ethernet MAC, for sending and receiving Ethernet frame data. A PHY management interface, MDIO, used to read and write the control and status registers of the PHY in order to configure each PHY before operation, and to monitor link status during operation.
What is the MDIO bus 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. The management of these PHYs is based on the access and modification of their various registers.
