IP1000ALF-DS-R04 데이터 시트보기 (PDF) - Unspecified

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IP1000ALF-DS-R04

Gigabit Ethernet NIC Single Chip

Unspecified 

IP1000A LF

Preliminary Data Sheet

Table 2-1 : Example Pseudo Packet Field Breakdown

PSEUDO PACKET OFFSET/

LENGTH INDICATOR PAIRS

0xC2

0x71

0xF4

0x10

ACTUAL RELATIVE

OFFSET

0xC

0x7

0x10

ACTUAL LENGTH

INDICATOR

0x2

0x1

0x4

If the pseudo packet shown in Figure 2-2 and described in Table 2-1 is placed into the IP1000A LF’s

transmit FIFO, for each received frame the IP1000A LF will take a CRC over the bytes described inTable

2-2.

Table 2-2 : Relationship Between Pseudo Packet and Receive Frame Bytes

ACTUAL RELATIVE

OFFSET

0xC

0x7

0x10

ACTUAL LENGTH

INDICATOR

0x2

0x1

0x4

BYTE OFFSETS OF RECEIVE

FRAME TO CALCULATE CRC OVER

0xC, 0xD

0x15

0x26, 0x27, 0x28, 0x29

If a CRC calculation over the received frame bytes indicated by the pseudo packet (in this example,

those bytes described byTable 2-2) matches the CRC value in the pseudo packet (in this example

0xF31908D7) the IP1000A LF will assert a wake event. Note, this matching technique may result in false

wake events being reported to the host system as it is possible that more than one set of byte values

specified by the pseudo packet may result in the same CRC value.

The IP1000A LF also supports Magic Packet™ technology developed by Advanced Micro Devices to

allow remote wake-up of a sleeping station on a network via transmission of a special frame. Once the

IP1000A LF has been placed in Magic Packet mode and put to sleep, it scans all incoming frames

addressed to it for a data sequence consisting of 16 consecutive repetitions of its own 48-bit Ethernet

MAC StationAddress. This sequence can be located anywhere within the frame, but must be preceded

by a synchronization stream. The synchronization stream is defined as 6 bytes of 0xFF. For example, if

the MAC address programmed into the StationAddress register is 0x11:22:33:44:55:66, then the

IP1000A LF would be scanning for the frame data shown in Figure 2-3.

Copyright © 2005, IC Plus Corp.

18/75

July 5, 2005

IP1000A LF-DS-R08

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