Power Management

The Ethernet controller generates a wakeup event after receiving any packet whose destination address matches one of the 16 valid programmed Receive Addresses if the Directed Exact Wakeup Enable bit is set in the Wakeup Filter Control Register (WUFC.EX).

 

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Match any pre-

 

 

 

programmed address

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

6.4.3.1.2Directed Multicast Packet

For multicast packets, the upper bits of the incoming packet’s destination address indexes a bit vector (Multicast Table Array) that indicates whether to accept the packet. If the Directed Multicast Wakeup Enable bit set in the Wakeup Filter Control Register (WUFC.MC) and the indexed bit in the vector is one then the Ethernet controller generates a wakeup event. The exact bits used in the comparison are programmed by software in the Multicast Offset field of the Receive Control Register (RCTL.MO).

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See Section 6.4.3.1.2.

 

 

 

 

 

 

6.4.3.1.3

Broadcast

 

 

 

 

 

 

 

If the Broadcast Wakeup Enable bit in the Wakeup Filter Control Register (WUFC.BC) is set, the

 

 

Ethernet controller generates a wakeup event when it receives a broadcast packet.

 

 

 

 

 

 

 

 

 

 

 

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FF*6

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6.4.3.1.4

Magic Packet*1

 

 

 

 

 

 

Magic Packet* technology is defined at: http://www.amd.com/products/npd/overview/20212.html.

The Ethernet controller expects the destination address to:

1.Be the broadcast address (FF.FF.FF.FF.FF.FF)

2.Match the value in Receive Address Register 0 (RAH0, RAL0). This is initially loaded from the EEPROM but can be changed by the software driver.

3.Match any other address filtering enabled by the software driver.

The Ethernet controller searches for the contents of Receive Address Register 0 (RAH0, RAL0) as the embedded IEEE address. It considers any non FF byte after a series of at least 6 FFs to be the start of the address for comparison purposes (for example, it catches the case of 7 FFs followed by the address). As soon as one of the first 96 bytes after a string of FFs doesn’t match, it continues to search for anther set of at least 6 FFs followed by the 16 copies of the IEEE address later in the packet. Note that this definition precludes the first byte of the destination address from being FF.

1.Not applicable to the 82541ER.

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Software Developer’s Manual

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Intel Intel Gigabit Ethernet Controllers, PCI-X manual Broadcast, Directed Multicast Packet, Magic Packet*1, FF*6 Compare