Intel PCI User Manual
Software Developer’s Manual
145
Power Management
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
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
EEPROM, Ethernet controller starts up with the Receive Address Register 0 (RAH0, RAL0)
loaded from the EEPROM. This is enables it to accept packets with the matching IEEE address
loaded from the EEPROM. This is enables it to accept packets with the matching IEEE address
before the driver comes up.
Note:
Accepting broadcast magic packets for wakeup purposes when the Broadcast Accept bit of the
Receive Control Register (RCTL.BAM) is 0b is a change from the 82544GC/EI Ethernet
controller, which initialized RCTL.BAM to 1b if APM was enabled in the EEPROM, but then
controller, which initialized RCTL.BAM to 1b if APM was enabled in the EEPROM, but then
required that bit to be 1b to accept broadcast Magic Packets, unless broadcast packets passed
another perfect or multicast filter.
Offset
# of
bytes
Field
Value
Action
Comment
0
6
Destination Address
Compare
MAC Header –
processed by main
address filter
processed by main
address filter
6
6
Source Address
Skip
12
a
8
Possible LLC/SNAP Header
Skip
12
a
4
Possible VLAN Tag
Skip
12
a
4
Type
Skip
any
6
Synchronizing Stream
FF*6+
Compare
any+6
96
16 copies of Node Address
A*16
Compare
Compared to Receive
Address Register 0
(RAH0, RAL0)
Address Register 0
(RAH0, RAL0)
a.
Not applicable to the 82541PI/GI/EI and 82547GI/EI.