Wake On Lan Mode/Low-Power; Description - Broadcom NetXtreme/NetLink BCM5718 Series Programmer's Manual

BCM5718 Programmer's Guide

Wake on LAN Mode/Low-Power

Description

The Ethernet controller uses the ACPI D3 hot/cold (low-power) state to conserve energy. The OS power
management policy notifies device drivers to initiate power management transitions. The device driver should
move the MAC into the D3 hot/cold power state—a response to the power management request. While the
Ethernet controller is in a D3 state, the RX MAC will filter incoming packets. The RX MAC compares incoming
traffic for Interesting Packet pattern matches. The Ethernet controller asserts the PCI PME signal, when a
positive WOL packet comparison is made. The PME signal notifies the Operating System and host device driver
to transition the MAC into the D0 (high power) state.
WOL mode is a combination of PHY and MAC configurations. Both the PHY and MAC must be configured
correctly to enable Broadcom's WOL technology. The Ethernet controller provides WOL pattern filters for 10/
100 wire speeds.
The Ethernet controller supports both Interesting Packet pattern matching the AMD Magic Packet proprietary
technology for WOL. The WOL support for the AMD Magic Packet format does not require host software to
configure a pattern filter. The Magic Packet comparison is made in hardware and is enabled through a register
interface. The AMD Magic Packet can be either broadcast or directed, and must contain the receiver's MAC
address at least six times (repeating) in the packet. The Magic Packet wake-up is configured different from
pattern match wake-up.
The following components are involved in WOL operation:
• Internal memory
• WOL Pattern Pointer register
• WOL Pattern Configuration register
• WOL streams
• Pattern data structure
• GPIO
• Firmware mailbox
• PHY auto-negotiation
• Ethernet controller power management
Broadcom
®
January 29, 2016 • 5718-PG108-R
Wake on LAN Mode/Low-Power
Page 212