2009-11-17 05:24 AM
multicast hash table, which CRC is used?
2011-05-17 04:30 AM
Hi everybody,
I'm making an small sensor thing on ethernet, it's using multicast UDP packets for communication. The ethernet chip has a hash table filter for multicast packets. So far so good, but I don't see which CRC algorithm is used for hashing MAC addresses. This is what the manual says: ''For hash filtering, the MAC uses the 6 upper CRC bits of the received destination address to index the content of the Hash table. A value of 000000 selects bit 0 in the selected register, and a value of 111111 selects bit 63 in the Hash Table register. If the corresponding bit (indicated by the 6-bit CRC) is set to 1, the unicast frame is said to have passed the Hash filter; otherwise, the frame has failed the Hash filter.'' Are there implementation example around?