Fault Detection and Board-Level Diagnosis by Signature Analysis

这是波士顿大学的M.Karpovsky教授和马萨诸塞大学的D.Pradhan共同努力的成果。拟议的调查有两个方面。第一个涉及通过压缩测试响应来进行故障检测。错误(故障的表现)被定义为实际测试响应和无故障响应之间的分量智能异或。如果观察到的签名(压缩测试响应)等于基准，则屏蔽故障。因此，根据误差的统计，最优压缩器是将测试响应压缩到参考中的概率最小化的压缩器。对于给定的被测电路，当错误序列中包含的错误序列的分布是已知的时，最优压缩器的设计正在被研究。这项工作也是基于有限域上的单个纠错码。第二个滑板。通过特征分析进行层次诊断。目标是分析板载冗余芯片的硬件复杂度与测试时间之间的折衷关系。目前正在研究两种基于测试响应压缩的技术。这些是；空格。测试响应的时间压缩，空间压缩机以前研究的扩展；以及在有限域上用Hamming代码进行板级诊断。卡尔波夫斯基教授和普拉丹教授都是杰出的研究人员，在过去的十年里有着坚实的成就记录，他们很有可能继续一流的研究。测试响应分析这一研究课题对工业很重要，是设计、工具和测试计划中的一个高优先级类别。

This is a collaborative effort between Professors M. Karpovsky at BostonUniversity and D. Pradhan at the University of Massachusetts. The proposedinvestigations are two.fold. The first concerns fault detection by acompression of test responses. Errors (manifestations of faults) are definedas the component.wise exclusive OR between actual test responses and fault.free responses. Faults are masked if the observed signature (compressed test response) is equal to the reference. Thus, depending on the statistics of theerrors, an optimal compressor is the compressor that minimizes a probabilitythat the test responses are compressed into the reference. The design ofoptimal compressors when the distribution of ones contained in error sequences is known for a given circuit under test is being investigated. This work isalso based on single error correcting codes over a finite field. Second isboard . level diagnosis by signature analysis. The objective is to analyzetradeoffs between the hardware complexity of the redundant chips on the boardand test time. Two techniques, based on compression of test responses, arebeing pursued. These are; space . time compression of test responses, anextension of previous research in space compressors; and board diagnosis byHamming codes over a finite field. Professors Karpovsky and Pradhan, are outstanding researchers with solidrecords of accomplishment over the past decade, and that they are very likelyto continue first class research. The research topic, test response analysis, is important to industry, and is a high.priority category within the Design,Tools and Test Program.