1.2.7 Ethernet Functionality
The CryptoAuth Pro Trust Platform supports 10BASE-T/100BASE-T Ethernet functionality. The PIC32CX1025SG41 provides the Media Access Controller (MAC) functionality, and the KSZ8091RNA Ethernet Transceiver provides the physical layer interface. The board utilizes the Reduced Media-Independent Interface (RMII).
Microcontroller Interface
| SG41 Connections | KSZ8091RNACA | SG41 Connections | |||
|---|---|---|---|---|---|
| Pin # | Pin # | Pin Name | Pin Name | Pin # | Pin # |
| 1.2V Decoupling | 1 | VDD_1V2 | RST | 24 | PA16 |
| 3.3V Analog Supply | 2 | VDDA_3V3 | SPEED | 23 | J702 |
| PA22 | 3 | RXP | GND | 22 | GND |
| PA23 | 4 | RXM | TXD1 | 21 | PA19 |
| PB01 | 5 | TXM | TXD0 | 20 | PA18 |
| PB02 | 6 | TXP | TXEN | 19 | PA17 |
| PC00 | 7 | XO | INTRP | 18 | PC21 |
| PB09 | 8 | XI | PME_EN | 17 | J701 |
| External Resistor | 9 | REXT | REF_CLK | 16 | PA14 |
| PA21(IOSET4) | 10 | MDIO | PHYAD | 15 | J700 |
| PA20 | 11 | MDC | VDDIO | 14 | 3.3V |
| PA12 | 12 | RXD1 | RXD0 | 13 | PA13 |
Ethernet Feature Selection
The board is set up with three selection jumpers that control features of the Ethernet PHY,
provided the PHY has been configured to make use of one or more of these features.
| Jumper # | Function | Jumper Position | |
|---|---|---|---|
| J700 | PHY Physical Address | 2-3 (Default) | PhyAdd = 00000b |
| 1-2 | PhyAdd = 00011b | ||
| J701 | Wake-on LAN Enable | 2-3 (Default) | Disabled |
| 1-2 | Enabled | ||
| J702 | Auto Negotiation and Speed Mode | 1-2 (Default) | Enable Auto Negotiation and set speed to 100 Mbps |
| 2-3 | Disable Auto Negotiation and set speed to 10 Mbps |
MAC Address
The board comes mounted with an AT24MAC402 serial EEPROM pre-progammed with a MAC address. The MAC address is stored in the serial EEPROM and can only be read. The serial EEPROM can also be used to store other data beyond the MAC Address. If so desired, the main memory array can be write-protected.
The Serial EEPROM has three different I2C addresses that allow access to different
parts of the memory array. The addresses shown below are the default addresses for the EV89U05A development board. Addresses can be modified by the way
resistors R601 through R606 are populated. Note that modifications of these resistors adjust
all three of the addresses. See the AT24MAC402 data sheet for more details.
| I2C Address (7-Bit) | Function | Access Type | Comments |
|---|---|---|---|
| 0x56 | General Purpose Memory Array Address | R/W | Setup up for Read/Write Access. Can be write-protected through the removal of resistor R608. |
| 0x5E | MAC Address | R | Can only be read. Cannot be overwritten. |
| 0x36 | WP Register Address | R/W | Used to check the write protection status of the memory. |