An ARP request event is detected when all of the following are true.
- ARP request events are enabled through bit [17] of the wake-on-LAN register
- Broadcasts are allowed by bit [5] in the network configuration register
- RX frame has a broadcast destination address (bytes 1 to 6)
- RX frame has a specific type ID field of
0x0806(bytes 13 and 14) - RX frame has an ARP operation field of
0x0001(bytes 21 and 22) - The least significant 16 bits of the frame's ARP target protocol address (bytes 41 and 42) match the value programmed in bits[15:0] of the wake-on-LAN register
The decoding of the ARP fields adjusts automatically if a VLAN tag is detected
within the frame. The reserved value of 0x0000 for the wake-on-LAN
target address value does not cause an ARP request event, even if matched by the
frame.