Patent attributes
A low-heat, large-scale ternary content-addressable memory (TCAM) efficiently compares one or more input records with a set of entries. Compression may also be used. X bits are eliminated from entries and in some embodiments, a subset of non-X bits are also eliminated, minimizing entries that must be searched. Entry bit sets can be converted into sets of fields. A useful set of fields is a triplet comprising a start field, a length field, and a data field. Hashing determines the RAM line of the TCAM in which entries are stored and which RAM line is to be compared with a given input. Searches are only needed on entries in RAM lines corresponding to inputs of interest. Priority values decide the winner if more than one TCAM entry in the appropriate RAM line matches the input. Bin packing can be used to optimally allocate TCAM entries across different possible RAM lines.
