A Regular Expression Matching Circuit Based on a Decomposed Automaton

In this paper, we propose a regular expression matching circuit based on a decomposed automaton. To implement a regular expression matching circuit, first, we convert regular expressions into a non-deterministic finite automaton (NFA). Then, to reduce the number of states, we convert the NFA into a modular non-deterministic finite automaton with unbounded string transition (MNFAU). Next, to realize it by a feasible amount of hardware, we decompose the MNFAU into the deterministic finite automaton (DFA) and the NFA. The DFA part is implemented by an off-chip memory and a simple sequencer, while the NFA part is implemented by a cascade of logic cells. Also, in this paper, we show that the MNFAU based implementation has lower area complexity than the DFA and the NFA based ones.

• Type: Journal
• Year: 2011
• Where: ARC
• Authors: Hiroki Nakahara, Tsutomu Sasao, Munehiro Matsuura
• Keywords: ARC 2011, Hardware, Non-deterministic finite Automaton, Regular Expressions, finite Automaton