Exact AEP model in signature analysis using LCM

Linear compacting modules (LCMs) cover a wide range of compacting machines, of which linear feedback shift registers (LFSRs) and linear cellular automata (LCA) are two examples. An exact analytical model for aliasing error probability (AEP) in signature analysis using LCMs is derived. The model quantitatively specifies the effects of the LCM architecture, including the number of stages, the LCM interconnection, of the test pattern length and the binary stream error statistics. We show that the bit selection criterion used for calculation of the AEP of the external- and internal-Exclusive-Or (XOR) LFSRs is not valid in less specific cases. Hence, the authors introduce a new criterion for the bit selection for the general case. The use of a general LCM simplifies the design and implementation of the Application Specific ICs (ASICs) by providing a flexible (and uniform) structure that can be easily integrated with neighboring structures. This could result in hardware savings exceeding 66%