9.2.4 Signal Interfaces
The GMAC includes the following signal interfaces:
- Media interface supports MII/ RMII/RGMII and connects to the external PHY
- Management Data Input/Output (MDIO) connects to the external PHY for management
- Configuration interface
- System bus interface for direct memory access (DMA)
- GTSUCOMP signal for TSU timer count value comparison
| Signal Name | Function | MII | RMII | RGMII |
|---|---|---|---|---|
| GTXCK | Transmit Clock or Reference Clock | TXCK | REFCK | TXCK |
| G125CK | 125 MHz input Clock | Not Used | Not Used | 125 MHz Ref Clk |
| GTXEN | Transmit Enable | TXEN | TXEN | TXCTL |
| GTX[3:0] | Transmit Data | TXD[3:0] | TXD[1:0] | TXD[3:0] |
| GTXER | Transmit Coding Error | TXER | Not Used | Not Used |
| GRXCK | Receive Clock | RXCK | Not Used | RXCK |
| GRXDV | Receive Data Valid | RXDV | CRSDV | RXCTL |
| GRX[3:0] | Receive Data | RXD[3:0] | RXD[1:0] | RXD[3:0] |
| GRXER | Receive Error | RXER | RXER | Not Used |
| GCRS | Carrier Sense and Data Valid | CRS | Not Used | Not Used |
| GCOL | Collision Detect | COL | Not Used | Not Used |
| GMDC | Management Data Clock | MDC | MDC | MDC |
| GMDIO | Management Data Input/Output | MDIO | MDIO | MDIO |