ATSAME54P20A has a built-in 10/100Mbps Ethernet IEEE® 802.3 compatible MAC with RMII interface. The MAC also supports energy efficient Ethernet (IEEE 802.3az). SAM E54 Xplained Pro connects the MAC to a Micrel KSZ8091RNACA RMII physical-layer transceiver (PHY), with IEEE 802.3az support, which is connected to one RJ45 Ethernet connector.
A unique EUI-48 address is available on every SAM E54 Xplained Pro through the onboard AT24MAC402, the EUI-48 address can be used as a MAC address for the KSZ8091RNACA. The address is also programmed into the onboard EDBG. For more information, see Kit Specific Data.
The table below lists all pins connected from the ATSAME54P20A to the Ethernet PHY.
| SAM E54 pin | Function | Ethernet function | Shared functionality |
|---|---|---|---|
| PA14 | GTXCK | REF_CLK | PCC |
| PA17 | GTXEN | TXEN | PCC |
| PA18 | GTX0 | TXD0 | PCC |
| PA19 | GTX1 | TXD1 | PCC |
| PC20 | GRXDV | CRS_DV | |
| PA13 | GRX0 | RXD0 | PCC |
| PA12 | GRX1 | RXD1 | PCC |
| PA15 | GRXER | RXER | PCC |
| PC11 | GMDC | MDC | PCC |
| PC12 | GMDIO | MDIO | PCC |
| PD12 | GPIO | INTERRUPT | |
| PC21 | GPIO | RESET |
The KSZ8091RNACA also has a set of parameters that are latched in during reset based on I/O pin levels. These configuration options have a default mode on the kit done by external pull-up and pull-down resistors. For detailed information about the configuration, see the KSZ8091RNACA datasheet.
| Configuration name | Default value on kit | Default configuration |
|---|---|---|
| PHYAD | 00 | The PHYs address is 00000 |
| PME_EN | 0 | Disable PME Enable output for Wake-On-LAN |
| ANEN_SPEED | 1 | Auto negotiation enabled and 100Mbps link speed enabled |