Intel 82558 Manuale Utente

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The 82559 Port commands are summarized in 

, which also includes the new Dump Wake-

up Packet command:

Following the Dump Wake-up command, the 82559 writes the stored data of the wake-up packet to 
the host memory, starting at the address specified in the pointer field. The dump data structure is 

shown below.

COEFFICIENTS = 0x04C11DB7;
Signature = 0;

for(n=i=0; n<128 & n<FrameLength; ++n)
{

if(Byte n of the Frame is in the

Flexible Filter)

{

ShiftBy = (i modulo 3) * 8;

if(Signature AND 0x80000000)

{

Signature = (Signature << 1)

XOR

(FrameByte << ShiftBy)

XOR

COEFFICIENTS;

}
else
{
Signature = (Signature << 1) XOR

(FrameByte << ShiftBy);

}
++i;

}

}

output bits 0-23 of Signature

// CRC Polynomial Coefficients
// Initialize the CRC Signature

// Search the frame, using only bytes
that are part of the flexible filter
pattern mask.

// Shift factor to move the frame byte to 

bit position 0, 8 or 16 of the 32-bit 

Dword.

// Bit position at 24 of the Dword is not 

used, because the signature is only 24 

bits.

// If the most significant bit is 1, XOR 

in the coefficients, previous signature 

and frame byte shifted over to the 

proper position.

// Otherwise, just XOR the previous 

signature and frame byte shifted over to 

the proper position.

// Include the Dword slot for the next 

frame byte that is in the pattern mask.

Software Reset

Don't care

0000

Self Test

Self test results pointer (16-byte alignment)

0001

Selective Reset

Don't care

0010

Dump

Dump area pointer (16-byte alignment)

0011

Dump Wake-up

Dump area pointer (16-byte alignment) 

0111