METHOD AND SYSTEM FOR SEARCHING COINCIDENCE OF PATTERNS

摘要

PURPOSE: To provide a method for searching pattern matching between the partial strings of both recent character strings in the past and at present by performing recursive comparison and forward or backward collation to 1st and 2nd character strings in a buffer. CONSTITUTION: A history buffer 203 and a comparator 205 form a matching register M. A coincidence look-ahead MLA unit 217 responds to signals from the matching register M and a main selection PS register 207. The PS register 207 loads in parallel the matching register M. The MLS 217 determines the flow, including parallel load or cyclic shift through the PS register 207. Thus, one piece of operation at the PS register 207 is decreased. After one address in a final marker inside the PS register 207 is solved, a value subtracting '1' from a matched length is subtracted from the address and a matching start position is provided by an offset address calculation unit 209. Finally, an edge detection circuit leads the end of string matching out of a MLA signal on a route 219.