Patent attributes
A system includes a first multi-port RAM storing an instruction table. The instruction table specifies a regular expression for application to a data stream and a second multi-port RAM configured to store a capture table having capture entries decodable for tracking position information for a sequence of characters matching a capture sub-expression of the regular expression. The system includes a regular expression engine processing the data stream to determine match states by tracking active states for the regular expression and priorities for the active states by storing the active states of the regular expression in a plurality of priority FIFO memories in decreasing priority order. The system includes a capture engine operating in coordination with the regular expression engine to determine character(s) of the data stream that match the capture sub-expression based on the active state being tracked and decoding the capture entries of the capture table.