Data relay apparatus, content addressable/associative memory device, and content addressable/associative memory device use information search method

A content addressable/associative memory device having the function of searching stored information to be searched, the device comprising:

• a data storage circuit for storing a plurality of pieces of information to be searched;
• an analysis circuit for generating, at the time of a search request including a plurality of search keys and a plurality of pieces of applied mask information each of which indicates an area to be searched by each of the plurality of search keys being inputted, a plurality of search conditions each including a search key and a piece of applied mask information by analyzing the structure of the search request;
• and
• a search circuit for searching the data storage circuit for a piece of information to be searched corresponding to each search condition generated by the analysis circuit, and for outputting a memory address uniquely associated with the detected piece of information to be searched.

A content addressable/associative memory device use information search method for searching for information regarding a packet by using a content addressable/associative memory device, the method comprising the steps of:

• outputting, by a network processor, a search request including a plurality of elements in the inputted packet treated as a plurality of search keys and a plurality of pieces of applied mask information each of which indicates an area to be searched by each of the plurality of search keys;
• analyzing the structure of the search request and generating a plurality of search conditions each including a search key and a piece of applied mask information;
• searching a plurality of pieces of information to be searched which are stored in advance in the content addressable/associative memory device for a piece of information to be searched corresponding to a search condition, and outputting a memory address uniquely associated with the piece of information to be searched corresponding to the search condition;
• and
• outputting a stored candidate search result associated with the memory address from a memory device in which a plurality of candidate search results are stored as a search result.