Abstract: A new test data compression method is proposed based on encoding the data blocks which are sequential or non-continuous.In order to improve the efficiency of the code，binary code with fixed length is used to express the length information of the sequential data block.On the other hand，the sequences which don’t have enough length is made to be non-continuous data blocks by some strategy，and not be encoded，so it can avoid the situation that short run length sequences replaced by long length code.The rule proposed by the method reduces the complexity of encoding which makes use of prefix and tail code separately，so the process of its encoding and decoding is simple，and the protocol of communication is also simple.Experimental results for ISCAS-89 benchmarks show that our new technique results in much better compression ratios than FDR code and Golomb code.

Key words: test data compression, encode, sequential and non-continuous data block, system-on-a-chip

摘要： 提出了一种新的基于连续及非连续长度块编码的测试数据压缩方法，该方案从提高码字利用率的目的出发，利用定长的二进制码字表示连续长度块的长度信息，同时，将连续位长度不足的序列按一定的策略划为非连续块，并且不对其进行编码，故有效地避免了用长码字替换短游程序列的情况。该方案的编码规则减少了使用前、后缀形式编码的复杂性，所以其编码及解码过程简单，同时具有简单的通讯协议。对ISCAS-89标准电路Mintest集的压缩结果表明，提出的方案较FDR码和Golomb码都具有更好的压缩效率。

关键词: 测试数据压缩, 编码, 连续及非连续块, 系统芯片