9 RXD1 Receive data
10 GND Connected to Board Ground
11 CRS_DV Carrier Sense/Receive Data Valid
12 GND Connected to Board Ground
13 TXD0 Transmit data
14 GND Connected to Board Ground
15 TXD1 Transmit data
16 GND Connected to Board Ground
17 TX_EN Transmit enable
18 GND Connected to Board Ground
19 RX_ER Receive Error, keep float at system side
20 GND Connected to Board Ground
21 I2C_SDA Used for testing. Keep float at system side.
22 GND Connected to Board Ground
23 I2C_SCL Used for testing. Keep float at system side.
24 GND Connected to Board Ground
25 GND Connected to Board Ground