82583V Datasheet, PDF (183/374 Pages) Intel Corporation – Intel® 82583V GbE Controller

Power Management and Delivery—82583V GbE Controller
8.5.3.1.4
Note:
Magic Packet*
Once the 82583V has been put into the Magic Packet* mode, it scans all incoming
frames addressed to the node for a specific data sequence, which indicates to the
controller that this is a Magic Packet* frame. A Magic Packet* frame must also meet the
basic requirements for the LAN technology chosen, such as SOURCE ADDRESS,
DESTINATION ADDRESS (which may be the receiving station's IEEE address or a
MULTICAST address which includes the BROADCAST address), and CRC. The specific
data sequence consists of 16 duplications of the IEEE address of this node, with no
breaks or interruptions. This sequence can be located anywhere within the packet, but
must be preceded by a synchronization stream. The synchronization stream enables
the scanning state machine to be much simpler. The synchronization stream is defined
as 6 bytes of 0xFF. The 82583V also accepts a broadcast frame, as long as the 16
duplications of the IEEE address match the address of the machine to be awakened.
The 82583V expects the destination address to either:
1. Be the broadcast address (0xFF.FF.FF.FF.FF.FF)
2. Match the value in Receive Address Register 0 (RAH0, RAL0). This is initially loaded
from the NVM but might be changed by the software device driver.
3. Match any other address filtering enabled by the software device driver.
The 82583V searches for the contents of Receive Address Register 0 (RAH0, RAL0) as
the embedded IEEE address. It considers any non-0xFF byte after a series of at least 6
0xFFs to be the start of the IEEE address for comparison purposes. (that is it catches
the case of 7 0xFFs followed by the IEEE address). As soon as one of the first 96 bytes
after a string of 0xFFs doesn't match, it continues to search for anther set of at least 6
0xFFs followed by the 16 copies of the IEEE address later in the packet.
This definition precludes the first byte of the destination address from being 0xFF.
A Magic Packet's* destination address must match the address filtering enabled in the
configuration registers with the exception that broadcast packets are considered to
match even if the Broadcast Accept bit of the Receive Control Register (RCTL.BAM) is
0b. If APM Wakeup is enabled in the NVM, the 82583V starts up with the Receive
Address Register 0 (RAH0, RAL0) loaded from the NVM. This enables the 82583V to
accept packets with the matching IEEE address before the software device driver
comes up.
Offset
# of
Bytes
Field
0
6
6
6
12
8
12
4
12
4
Any
6
any+6
96
Destination Address
Source Address
Possible LLC/SNAP Header
Possible VLAN Tag
Type
Synchronizing Stream
16 copies of Node Address
Value
Action
Compare
0xFF*6+
Skip
Skip
Skip
Skip
Compare
A*16
Compare
Comment
MAC Header –
processed by main
address filter
Compared to Receive
Address Register 0
(RAH0, RAL0)
183