A Smith-Waterman Systolic Cell

With an aim to understand the information encoded by DNA sequences, databases containing large amount of DNA sequence information are frequently compared and searched for matching or near-matching patterns. This kind of similarity calculation is known as sequence alignment. To date, the most popular algorithms for this operation are heuristic approaches such as BLAST and FASTA which give high speed but low sensitivity, i.e. significant matches may be missed by the searches. Another algorithm, the Smith-Waterman algorithm, is a more computationally expensive algorithm but achieves higher sensitivity. In this paper, an improved systolic processing element cell for implementing the SmithWaterman on a Xilinx Virtex FPGA is presented.