Automatic test pattern generation

About: Automatic test pattern generation is a research topic. Over the lifetime, 8214 publications have been published within this topic receiving 140773 citations. The topic is also known as: ATPG.

Improved SAT-based ATPG: more constraints, better compaction

Abstract: Automatic Test Pattern Generation (ATPG) based on Boolean Satisfiability (SAT) is a robust alternative to classical structural ATPG. Due to the powerful reasoning engines of modern SAT solvers, SAT-based algorithms typically provide a high test coverage because of the ability to reliably classify hard-to-detect faults. However, a drawback of SAT-based ATPG is the test compaction ability. In this paper, we propose an enhanced dynamic test compaction approach which leverages the high implicative power of modern SAT solvers. Fault detection constraints are encoded into the SAT instance and a formal optimization procedure is applied to increase the detection ability of the generated tests. Experiments show that the proposed approach is able to achieve high compaction -- for certain benchmarks even smaller test sets than the currently best known results are obtained.

Partial scan by use of empirical testability

Abstract: The objective of the partial scan method proposed is to obtain maximum fault coverage for the number of scan elements selected. Empirical testability difference (ETD), a measure of the potential improvement in the overall testability of the circuit, is used to successively select storage elements for scan. ETD is calculated by using testability measures based on empirical evaluation of the circuit with the actual test sequence generator. In addition, ETD focuses on the hard-to-detect faults rather than all faults once such faults are known. The method has been extensively tested with ten of the sequential circuits given by F. Brglez et al. (1989) using the FASTEST provided by T. Kelsey and K. Saluja (1989). The results of these tests indicate that ETD yields on average either 27% of the number of uncovered faults for the same number of scan elements or 21% fewer scan elements for the same fault coverage compared to the other methods studied. >

A graph traversal based framework for sequential logic implication with an application to C-cycle redundancy identification

Abstract: This paper presents a new graph traversal based framework for sequential logic implication called GRAPH-SIMP. Due to the prohibitive time and space cost, few previous works target the discovery of sequential indirect implications that span multiple time frames. By using an efficient graph data structure and incorporating a graph reduction step into the implication generation process, our approach provides an efficient support for sequential implication. Sequential logic implication has many useful applications, one of which is sequentially redundant fault identification. We show that sequential implications found by GRAPH SIMP allow us to find more sequential redundancies than previously reported. Results of testing our implication algorithm against ISCAS89 circuits show that high implication coverage is essential to identifying redundant faults.

Reuse-based test access and integrated test scheduling for network-on-chip

Abstract: In this paper, we propose a new method for test access and test scheduling in NoC-based system. It relies on a progressive reuse of the network resources for transporting test data to routers. We present possible solutions to the implementation of this scheme. We also show how the router testing can be scheduled concurrently with core testing to reduce test application time. Experimental results for the ITC'02 SoC benchmarks show that the proposed method can lead to substantial reduction on test application time compared to previous work based on the use of serial boundary scan. The method can also help to reduce hardware overhead.

Assertion checking by combined word-level ATPG and modular arithmetic constraint-solving techniques

Abstract: We present a new approach to checking assertion properties for RTI, design verification. Our approach combines structural, word-level automatic test pattern generation (ATPG) and modular arithmetic constraint-solving techniques to solve the constraints imposed by the target assertion property. Our word-level ATPG and implication technique not only solves the constraints on the control logic, but also propagates the logic implications to the datapath. A novel arithmetic constraint solver based on modular number system is then employed to solve the remaining constraints in datapath. The advantages of the new method are threefold. First, the decision-making process of the word-level ATPG is confined to the selected control signals only. Therefore, the enumeration of enormous number of choices at the datapath signals is completely avoided. Second, our new implication translation techniques allow word-level logic implication being performed across the boundary of datapath and control logic, and therefore, efficiently cut down the ATPG search space. Third, our arithmetic constraint solver is based on modular instead of integral number system. It can thus avoid the false negative effect resulting from the bit-vector value modulation. A prototype system has been built which consists of an industrial front-end HDL parser, a property-to-constraint converter and the ATPG/arithmetic constraint-solving engine. The experimental results on some public benchmark and industrial circuits demonstrate the efficiency of our approach and its applicability to large industrial designs.