Intel 82557 Switch User Manual


 
10/100 Mbps Ethernet Controller Family Open Source Software Developer Manual 143
Wake-up Functionality
The controller only filters the shaded fields in the frame format above. Only the two low bytes of
the IP address are compared. The controller does not check for VLAN type (any frame with type
different than 0806 is treated as a VLAN frame if VLAN ARP is enabled).
A.4.4 Configuration Bits for Fixed Wake-up filters
The following configuration bits were added to the 82558 B-step to support fixed wake-up
filtering:
12 0806 Protocol type (0806 = ARP)
21 01 ARP opcode (01 = request)
38 X1, ... X4 A sequence of 4 bytes, which is the requested IP address
Ethernet Type II frame Ethernet Type II frame with VLAN type
msb lsb msb lsb
Destination
Address
FF FF FF FF FF FF
Destination
Address
FF FF FF FF FF FF
Source
Address
Source
Address
Frame
Type
06 08 12
VLAN
Header
Data 14
Frame
Type
06 08
01 18 Data 18
22 01 22
26 26
30 30
34 34
IP address x4 x3
x2 x1 38 38
42 IP address x4 x3 x2 x1 42
46 46
Offset Hexadecimal Pattern Description
Table 66. Fixed Wake-up Configuration Bits
Configuration Bit Description
VLAN ARP
This bit enables a wake-up event upon reception of ARP frames with a dynamic
presence of a VLAN header. This bit takes effect only if the ARP enable bit is
also set.
Link Status Change Wake
Enable
This bit enables assertion of the PME# signal upon a link status change event.
The PME# signal is further gated by the PME enable bit in the PMCSR.
ARP Wake Enable
This bit enables assertion of the PME# signal upon reception of ARP frames.
The PME# signal is further gated by the PME enable bit in the PMCSR.