基于三态信号的改进游程编码压缩方法

Improved Run Length Coding Compression Method Based on Tri-State Signal

为提高集成电路测试效率,提出一种结合三态信号的改进游程编码压缩方法。先对原始测试集进行部分输入精简处理并填充测试集的无关位,再对经过预处理的测试集根据游程长度进行变长分段处理找出最优段长。按照游程长度的出现频率对最优段长下的参考位设置编码表进行编码压缩,使用三态信号编码标志位并将编码压缩后的测试集存入自动测试设备(ATE),最终通过设计解压电路对ATE中存储的压缩数据进行无损解压。实验结果表明,在硬件开销未明显增加的情况下,该方法的测试数据平均压缩率达到74.39%,优于同类压缩方法。

To improve the efficiency of integrated circuit testing,this paper proposes an improved run length coding compression method using tri-state signal.First,part of the input in the test cube is reduced,and the unrelated bits of the test set are filled.Then the variable length segment compression is performed on the pre-processed test set according to the run length to find the optimal segment length.According to the frequency of the run length,the encoding table is designed for the reference bits under the optimal segment length for coding compression. Finally,the flag bits are encoded with tri-state signals,and the encoded and compressed test set is saved into the Automatic Test Equipment(ATE). The compressed data in ATE can be decompressed without loss by designing a decompression circuit.Experimental results show that the proposed method improves the average compression ratio to74.39% without a significant increase in the hardware overhead,which is better than other similar compression methods.