An efficient method for compressing test data

The overall throughput of automatic test equipment (ATE) is sensitive to 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. In this paper, we propose a new test data compression method that aims to fully utilize the unique characteristics of test data compression. The key idea of the proposed method is to perform the Burrows-Wheeler transformation on the sequence of test patterns, and then to apply run-length coding. The experimental results show that our compression method performs better than six other methods for compressing rest delta. The average compression ratio of the proposed method performed on five test data sets is 3/5, while that for the next best one, the LZW method, is 21.