82598EB Datasheet, PDF (150/596 Pages) Intel Corporation – Intel® 82598EB 10 Gigabit Ethernet Controller Datasheet

Intel^® 82598EB 10 GbE Controller - Wake Up
When APM Wakeup is enabled, the 82598 checks all incoming packets for Magic Packets*. Refer to
Section 3.3.2.3.1.4 for more information.
Once the 82598 receives a matching magic packet, it:
• Sets the PME_Status bit in the Power Management Control/Status Register (PMCSR) and issues a
PM_PME message (in some cases, this might be required to assert the WAKE# signal first to
resume power and clock to the PCIe interface).
• Stores the first 128 bytes of the packet in WUPM.
• Sets the Magic Packet Received bit in the WUS register.
• Sets the packet length in the WUPL register.
The 82598 maintains the first magic packet received in WUPM until the software device driver writes a
0b to the Magic Packet Received MAG bit in the WUS register.
APM wake up is supported in all power states and only disabled if a subsequent EEPROM read results in
the APM Wake Up bit being cleared or the software explicitly writes a 0b to the APM Wake Up (APM) bit
of the GRC register.
3.3.2.2 ACPI Power Management Wakeup
The 82598 supports ACPI power management based wake ups. It can generate system wake-up events
from three sources:
• Reception of a Magic Packet*.
• Reception of a network wake-up packet.
• Detection of a link change of state.
Activating ACPI power management wake up requires the following steps:
• The operating system (at configuration time) writes a 1b to the Pme_En bit (bit 8) of the PMCSR
register.
• The software device driver clears all pending wake-up status in the WUS register by writing 1b to
all the status bits.
• The software device driver programs the Wake Up Filter Control (WUFC) register to indicate the
packets it needs to wake up and supplies the necessary data to the IPv4/v6 Address Table (IP4AT,
IP6AT), Flexible Host Filter Table (FHFT). It can also set the Link Status Change Wake Up Enable
(LNKC) bit in the WUFC register to cause a wake up when the link changes state.
• Once the 82598 wakes up the system the driver needs to clear WUS and WUFC until the next
time the system goes to a low power state with wake up.
Normally, after enabling wake up, the operating system writes (11b) to the lower two bits of the PMCSR
to put the 82598 into low-power mode.
Once wake up is enabled, the 82598 monitors incoming packets, first filtering them according to its
standard address filtering method, then filtering them with all of the enabled wakeup filters. If a packet
passes both the standard address filtering and at least one of the enabled wake-up filters, the 82598:
• Sets the PME_Status bit in the PMCSR.
• If the PME_En bit in the PMCSR is set, asserts PE_WAKE_N.
• Stores the first 128 bytes of the packet in WUPM.
• Sets one or more of the Received bits in the WUS register (the 82598 sets more than one bit if a
packet matches more than one filter).
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