一种基于相容压缩和FDR编码压缩的综合压缩方法。该方法首先把原始测试集的测试向量转变成多扫描链的形式，利用测试向量间的相容关系进行第一次压缩——相容压缩，在此基础上对相容压缩过的测试集进行重排，使其仍然保持原始测试集中测试模式的排列特性，并对其进行优化排序，使得相邻模式间具有最少的不同位，最后利用FDR编码方法进行第二次压缩。

目前，减少测试应用时间和测试数据容量是测试领域的努力方向。本文提出的这种方法可以有效的减少存储容量和降低测试时间从而有效的降低了测试成本。与类似的纯编码压缩方法相比，如：Golomb码，统计码，基于字典的编码等压缩方法，其压缩效果更为显著。-The method of FDR codes compression based on compatible compression of multiple scan chains is presented chiefly in this paper. The test vectors are transferred to the pattern of the multiple scan chain and the compatible compression is implemented of first time. The next, the test vectors are reset after the compatible compression, but the character that there are a few different bits between test patterns of the test set is kept all the same. The test pattern was sorted to make the near mode have the least different bits, finally making use of the FDR code proceeds to compress for the second time.

Recently, reducing test application time and test data volume is a direction of effort in SoC design. This method can reduce the volume of test equipment and test times. Compared to the same type of the codes compression schemes, such as Golomb codes, statistical codes and compression using dictionary, the efficiency of the proposed scheme is better.