DEVICE DETECTING PRESCRIBED PATTERN IN DATA STREAM, METHOD FOR DETECTING PRESCRIBED PATTERN IN DATA STREAM AND METHOD IN NETWORK INTERFACE IDENTIFYING PRESCRIBED PATTERN IN DATA PACKET

摘要

PROBLEM TO BE SOLVED: To detect a prescribed pattern in a data stream by comparing a pattern data field with an adjacent group that selects the byte of a data stream and providing a comparator which outputs a comparison result. SOLUTION: A pattern matching circuit 62 uses a skip/ignoring field to minimize needed space quantity in memory and includes pattern memory 80 which stores pattern entries that specify respective patterns. Also, it includes a comparator 82 which compares one pattern data field that selects a stored pattern entry with a group which selects a byte from a packet data stream that is supplied from a medium access controller. Further, it contains a match logic 86 which receives a comparison result from the comparator 82 and decides the end of a comparison result based on an end bit from a state machine 84.