AM79C90JCTR datasheet(52/62 Pages) AMD

52 / 62 page

AMD

Am79C90

{

int k,i, byte; /* temporary array indices */

int hashcode; /* the object of this program */

char buf[80]; /* holds input characters */

for (i=0;i<8;i++) ladrf[i] = 0; /* clear log. adr. filter */

printf (”Enter Ethernet addresses as 6 octets separated by blanks.\n”);

printf (”Each octet is one or two hex characters. The first octet \n”);

printf (”entered is the first octet to be transmitted. The LSB of \n”);

printf (”the first octet is the first bit transmitted. After each \n”);

printf (”address is entered, the Logical Address Filter contents \n”);

printf (”are displayed, least significant byte first, with the \n”);

printf (”appropriate bits set for all addresses entered so far.\n”);

printf (”

To exit press the <Enter> key.\n\n”);

while (1)

{

loop:

printf (”\nEnter address: ”);

/* If 1st character = CR, quit, otherwise read address. */

gets (buf);

if ( buf[0] == ’\0’) break;

if (sscanf (buf, ”%x %x %x %x %x %x”,

&adr[0], &adr[1], &adr[2],&adr[3],&adr[4],&adr[5])

!= 6)

{ printf

(”Address must contain 6 octets separated by blanks.\n”);

goto loop;

}

if ((adr[0] & 1) == 0)

{ printf (”First octet of multicast address ”);

printf (”must be an odd number.\n”);

goto loop;

}

/* Initialize CRC */

for (i=0; i<32; i++) CRC[i] = 1;

/* Process each bit of the address in the order of transmission.*/

for (byte=0; byte<6; byte++)

for (i=0; i<8; i++)

updateCRC ((adr[byte] >> i) & 1);

/* The hash code is the 6 least significant bits of the CRC

in reverse order: CRC[0] = hash[5], CRC[1] = hash[4], etc.

hashcode = 0;

for (i=0; i<6; i++) hashcode = (hashcode << 1) + CRC[i];

/* Bits 3–5 of hashcode point to byte in address filter.

Bits 0–2 point to bit within that byte. */

byte = hashcode >> 3;

AM79C90JCTR Datasheet(PDF) 52 Page - Advanced Micro Devices

AM79C90JCTR Datasheet(HTML) 52 Page - Advanced Micro Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62

Datasheet Download

Link URL