TEST DATA COMPRESSION BASED ON BURROWS-WHEELER TRANSFORMATION AND RUN-LENGTH SCHEME

Abstract

Data compression has important application in the areas of file storage and transferring data form one computer to another. A simple characterization of data compression is that it involves transforming a string of characters in some representation. into a new string which contains the same information but whose length is as small as possible. The overall throughput of automatic test equipment (ATE) is affected by the download time of test data. An effective approach to the reduction of the download time is to compress test data before the download. A compression algorithm for test data should meet two requirements: lossless and simple decompression. Here a new test data compression method is proposed that aims to fully utilize the unique characteristics of test data compression. The key idea of the method is to perform the Burrows-Wheeler transformation on the sequence of test patterns and then to apply run-length coding. Experimental results show that this compression method performs better than the other methods for compressing test data The average compression ratio of this method performed on 10 test data sets is 9.74, while that for the next best one TDMT, is 9.53. The result also shows that this method indeed reduces the execution time significantly. The compression ratio is defined as the ratio of the number of bits required to represent an original uncompressed data to that of the compressed data. The software implementation is done in C programming language in windows 98 environment in order to compare the performance of run-length and TDMT compression scheme.