Achieving serendipitous N-detect mark-offs in Multi-Capture-Clock scan patterns

IET Computers & Digital Techniques

2018

Functional broadside tests are important for avoiding overtesting of delay faults during the application of scan-based tests. Multicycle tests have advantages in defect detection and test compaction. This study addresses the on-chip generation of primary input sequences for the application of multicycle functional broadside tests to a circuit that is embedded in a larger design. In this study, multicycle functional broadside tests are considered under two types of constraints: (i) functional constraints that the design imposes on the primary input patterns of the circuit, and (ii) test application constraints when direct access to the primary inputs of the circuit is not available, and the application of two or more consecutive primary input patterns requires hardware support. The use of multicycle functional broadside tests also results in an increased fault coverage.

Section: Introductionmentioning

confidence: 99%

On‐chip generation of primary input sequences for multicycle functional broadside tests

IET Computers & Digital Techniques

2018

“…A multi-cycle test for a scan circuit has several clock cycles between a scan-in and a scan-out operation. Multi-cycle tests are useful for several applications [1][2][3][4][5][6][7][8] including test compaction. The usefulness for test compaction results from the fact that a multi-cycle test with more clock cycles between scan operations can detect more faults.…”

Section: Introductionmentioning

confidence: 99%

On multi‐cycle test cubes

IET Computers & Digital Techniques

2013

This article studies the generation of test sets that consist of multi-cycle test cubes. Such test cubes have partiallyspecified scan-in states, and several functional clock cycles between scan operations. Test cubes are important for test data compression. In addition, multi-cycle tests can detect delay defects that are not detected by single-cycle tests. The use of multi-cycle test cubes is shown to reduce the number of test cubes required for detecting single stuck-at faults compared with the case where single-cycle test cubes are used. This article also shows that a multi-cycle test cube for a single stuck-at fault can have fewer specified scan-in values than a single-cycle test cube for the same fault. As a result, multi-cycle test cubes can be more effective for test data compression. This article also discusses the conditions under which multi-cycle test cubes can be merged in order to further reduce the number of test cubes in a test set.

“…Partial-scan circuits require several clock cycles for activating faults and propagating fault effects to observable outputs. Multicycle tests are also useful for circuits with multiple clock domains [3]- [4]. Even with a full-scan circuit and a single clock domain, multicycle broadside tests can be used for reducing the test application time [5]- [7].…”

Section: Introductionmentioning

confidence: 99%

On Transition Fault Diagnosis Using Multicycle At-Speed Broadside Tests

2011 Sixteenth IEEE European Test Symposium

2011

This paper studies issues related to transition fault diagnosis using multicycle broadside tests that are applied at-speed. Two transition fault models were proposed earlier for at-speed simulation, referred to as d -faults and x -faults. Both fault models account for the extra delay of a transition fault in order to allow at-speed simulation. However, they differ in the following ways. (1) The number of x -faults is equal to the number of conventional transition faults, while the number of d -faults grows with the number of cycles in a test. (2) Output responses of x -faults contain unspecified values that result in lower diagnostic resolution. The paper describes a fault diagnosis procedure that combines the use of x -faults for efficiency with the use of d -faults for diagnostic resolution.