Electronic Design Automation

3.5.1.1. Linear-decompression-based schemes

A class of test stimulus compression schemes is based on the use of linear decompressors to expand the data coming from the tester to fill the scan chains. Any decompressor that consists of only XOR gates and flip-flops is a linear decompressor [Könemann 1991]. Linear decompressors have a very useful property: their output space (i.e., the space of all possible test vectors that they can generate) is a linear subspace that is spanned by a Boolean matrix. In other words, for any linear decompressor that expands an m-bit compressed stimulus from the tester into an n-bit stimulus (test vector), there exists a Boolean matrix A^{n × m} such that the set of test vectors that can be generated by the linear ...