Good day!

For some reasons I want to handle multicast packets with CH579 Ethernet. As it contain only single perfect match filter, I need to use hash table (R32_ETH_HTL/R32_ETH_HTH) to accept only needed multicasts. Can you point me to code example of calculating hash table settings?

Hello,

     if you want to handle muticast packets, the hash table should set at this:

     MacCrc32 = CRC6Bit(MultiMac);
     if(MacCrc32 > 31)
     {
       MacCrc32 -=32;
       Hash1 |= ((UINT32)1<     }
     else
     {
       Hash0 |= ((UINT32)1<     } 
     R32_ETH_HTL  = Hash0;                                               
     R32_ETH_HTH  = Hash1;

     Funcation CRC6Bit of which is below:

     UINT8 CRC6Bit(UINT8 *mac_addr)
     {
        INT32 perByte;
        INT32 perBit;
        const UINT32 poly = 0x04C11DB7;
        UINT32 crc_value = 0xFFFFFFFF;
        UINT8 c;
        for ( perByte = 0; perByte < 6; perByte ++ )
        {
            c = *(mac_addr++);
            for ( perBit = 0; perBit < 8; perBit++ )
            {
                crc_value = (crc_value<<1)^((((crc_value>>31)^c)&0x01)?poly:0);
                c >>= 1;
            }
        }
        crc_value=crc_value>>26;                                     
        return ((UINT8)crc_value);
    }

   Besides, MacFilts has to be set in only way:

   R8_ETH_ERXFCON |= RB_ETH_ERXFCON_HTEN;

   It should be set followed by register "R32_ETH_HTH" being set. Otherwise, if you use UDP muticast, then the other type    network are not  commended being used together.