这是本文档旧的修订版！

MII（Media Independent Interface）

Ethernet MAC和PHY之间通讯的一种接口，最高支持100Mbps。

常用标准

IEEE 802.3u (Fast Ethernet Specification)： 802.3-2022 第22卷

MII信号连接如下图（图中PHY的TX和RX按按照MAC侧定义的，即MAC的TX应连接PHY的RX，MAC的RX连接PHY的TX）：

MII各信号的定义见下表：

Table 7: MII Signal Definitions
Signal Name	Source	Description
TXC	PHY	Transmit Clock.This clock is sourced bythe PHY and is25 MHz for 100 Mbps mode and 2.5 MHz for 10 Mbps mode.The PHY samples TXD on the rising edge of TXC.
TXEN	Switch/MAC	Transmit Enable.Active high single indicating that the current nibble on TXD is valid
TXD[3:0]	Switch/MAC	Transmit Data.Nibble-wide transmit data.
TXER	Switch/MAC	Transmit Error.Active high signal instructing the PHY to transmit an errored symbol
RXC	PHY	Receive Clock.This clock is sourced by the PHY and is 25 MHz for 100 Mbps mode and 2.5 MHz tor 10 Mbps mode.Ine MAC samples KXD on tne rising eage of KXC.
RXDV	PHY	Receive Data Valid.Active high signal indicating that the current nibble on RXD is valid
RXD[3:0]	PHY	Receive Data.Nibble-wide receive data.
RXER	PHY	Receive Error.Active high signal instructing the MAC that a packet error has been detected.
CRS	PHY	Carrier Sense.Active high signal indicating activity on the media.
COL	PHY	Collision.Active high signal indicating that a collision has occurred on the media.
MDC	Switch/MAC	Management Data Clock.
MDIO	Bidirectional	Management Data.