8.3Magic Packet™ Filter

The Magic Packet filter checks the destination address and data fields of all incoming packets. If the destination address matches the MAADR registers and the data field holds a valid Magic Packet pattern someplace

within it, then the packet will meet the Magic Packet filter criteria. The Magic Packet pattern consists of a sync pattern of six 0xFF bytes, followed by 16 repeats of the destination address. See Figure 8-4 for a sample Magic Packet.

8.4Hash Table Filter

The Hash Table receive filter performs a CRC over the six destination address bytes in the packet. The CRC is then used as a pointer into the bits of the EHT registers. If the pointer points to a bit which is set, the packet meets the Hash Table filter criteria. For example, if the CRC is calculated to be 0x5, bit 5 in the Hash Table will be checked. If it is set, the Hash Table filter criteria will be met. If every bit is clear in the Hash Table, the filter criteria will never be met. Similarly, if every bit is set in the Hash Table, the filter criteria will always be met.

8.5Multicast Filter

The Multicast receive filter checks the destination address of all incoming packets. If the Least Significant bit of the first byte of the destination address is set, the packet will meet the Multicast filter criteria.

8.6Broadcast Filter

The Broadcast receive filter checks the destination address of all incoming packets. If the destination address is FF-FF-FF-FF-FF-FF, the packet will meet the Broadcast filter criteria.