Signal Interface

The GMAC includes the following signal interfaces:

Table 1. GMAC Connections in Different Modes
Signal Name	Function	MII	RMII
GTXCK⁽¹⁾	Transmit Clock or Reference Clock	TXCK	REFCK
GTXEN	Transmit Enable	TXEN	TXEN
GTX[3..0]	Transmit Data	TXD[3:0]	TXD[1:0]
GTXER	Transmit Coding Error	TXER	Not Used
GRXCK	Receive Clock	RXCK	Not Used
GRXDV	Receive Data Valid	RXDV	CRSDV
GRX[3..0]	Receive Data	RXD[3:0]	RXD[1:0]
GRXER	Receive Error	RXER	RXER
GCRS	Carrier Sense and Data Valid	CRS	Not Used
GCOL	Collision Detect	COL	Not Used
GMDC	Management Data Clock	MDC	MDC
GMDIO	Management Data Input/Output	MDIO	MDIO

Note:

1.Input only. GTXCK must be provided with a 25 MHz / 50 MHz external crystal oscillator for MII / RMII interfaces, respectively.