应用扩展前缀编码的测试数据压缩方案

提出一种扩展前缀编码的测试数据压缩方案,采用变长到变长的编码方式对任意长度的0游程和1游程编码,代码字由前缀和尾部组成,用扩展的前缀表明编码的游程类型;不引入额外的标记位,并能有效地压缩芯片测试数据量.理论分析和实验结果表明:扩展前缀编码能取得比FDR编码更高的压缩率,能够更好地适应于多样的编码对象.解压时使用一种特殊的计数器简化控制电路,解码电路硬件开销小且较易实现.

Test Data Compression Using Extended Prefix Coding

A test data compression scheme based on extended prefix coding is presented.It is a variable-to-variable run length code based on encoding both runs of 0's and 1's.The code word consists of prefix and tail.The scheme uses extended prefix to indicate the type of run.It doesn't add an extra bit.So it can compress test data efficiently.Theoretical analysis and experimental results show that the proposed scheme can provide higher compression efficiency than FDR and has a better adaptability for various test set.Due to using a special shift counter to simplify the control circuit,the decompression circuit can be implemented easily and the hardware cost is low.