Increasingly, embedded system designers must exploit application-specific concurrency in order to obtain high performance. Often an application will exhibit several different styles and granularities of concurrency. An average embedded RISC processor is a poor platform when concurrency is a first-class concern. The Sub-RISC paradigm, on the other hand, allows designers to create programmable architectures with application-specific process-, data-, and datatype-level concurrency. This paper describes a Sub-RISC processor that accelerates regular expression matching for network intrusion detection. This processor is lightweight and can be tiled to search multiple packet streams in parallel. Unlike typical application-specific processors, designers are not burdened with assembly language programming. Instead, the language of regular expressions is used as a high-level programming abstraction. Results are shown for ASIC and FPGA implementations using regexp rules from the Snort database.