Method of Constructing the Pipe-Lined Content Addressable Memory for High Speed Lookup of Longest Prefix Matching Algorithm in Internet Protocol Address Lookup

摘要

PURPOSE: A method for configuring a pipeline CAM(Content Addressable Memory) for fast LPM(Longest Prefix Matching) searching in an IP address lookup process is provided to efficiently apply to fast LPM searching among the IP address lookup process of a router. CONSTITUTION: An input packet IP address(701), input data, is segmented by 4 bits, and total 32 bits are inputted to key field blocks 0 through 7. Each of the key field blocks(702) simultaneously executes a search to confirm whether the inputted 4-bit data exist in the CAM memory array of each key field block. Then each key field block supplies a searched result to a match block search and match vector generation logic(703). Based on the results of key field blocks 0 through 7, the match block search and match vector generation logic searches up to which key field block matching has been made.