Digi NS9215 - Manual (Page 335)

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E T H E R N E T C O M M U N I C A T I O N M O D U L E
Sample hash table code
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(*MERCURY_EFE).ht2.bits.data = SWAP32(hash_table[1]);
(*MERCURY_EFE).ht1.bits.data = SWAP32(hash_table[0]);
}
/ *
*
* Function: void eth_make_hash_table (WORD32 *hash_table)
*
* Description:
*
* This routine creates a hash table based on the CRC values of
* the MAC addresses setup by set_hash_bit(). The CRC value of
* each MAC address is calculated and the lower six bits are used
* to generate a value between 0 and 64. The corresponding bit in
* the 64-bit hash table is then set.
*
* Parameters:
*
* hash_table pointer to buffer to store hash table in.
*
* Return Values:
*
* none
*
*/
static void eth_make_hash_table (WORD32 *hash_table)
{
int index;
memset (hash_table, 0, 8); /* clear hash table*/
for (index = 0; index < mca_count; index++) /*for each mca address*/
{
set_hash_bit ((BYTE *) hash_table, calculate_hash_bit (mca_address
[index]));
}
}