Fault coverage refers to the percentage of some type of
fault that can be detected during the test of any engineered system. High fault coverage is particularly valuable during manufacturing test, and techniques such as
Design For Test (DFT) and
automatic test pattern generation are used to increase it.
Applications
Digital electronics
In
digital electronics
Digital electronics is a field of electronics involving the study of digital signals and the engineering of devices that use or produce them. It deals with the relationship between Binary number, binary inputs and outputs by passing electrical s ...
, fault coverage refers to
stuck-at fault coverage.
[{{Cite book , last=Williams , first=Thomas W. , title=How Should Fault Coverage Be Defined? , last2=Sunter , first2=Stephen K. , publisher=18th IEEE VLSI Test Symposium (VTS 2000), 30 April - 4 May 2000, Montreal, Canada , year=2000 , pages=325-328 , doi=10.1109/VTS.2000.10003] It is measured by sticking each pin of the hardware model at logic '0' and logic '1', respectively, and running the test vectors. If at least one of the outputs differs from what is to be expected, the fault is said to be detected. Conceptually, the total number of simulation runs is twice the number of pins (since each pin is stuck in one of two ways, and both faults should be detected). However, there are many optimizations that can reduce the needed computation. In particular, often many non-interacting faults can be simulated in one run, and each simulation can be terminated as soon as a fault is detected.
A fault coverage test passes when at least a specified percentage of all possible faults can be detected. If it does not pass, at least three options are possible. First, the designer can augment or otherwise improve the vector set, perhaps by using a more effective
automatic test pattern generation tool. Second, the circuit may be re-defined for better fault detectability (improved controllability and observability). Third, the designer may simply accept the lower coverage.
See also
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Design for testing
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Automatic test pattern generation
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Electronic design automation
Electronic design automation (EDA), also referred to as electronic computer-aided design (ECAD), is a category of software tools for designing Electronics, electronic systems such as integrated circuits and printed circuit boards. The tools wo ...
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Fault detection and isolation
Fault detection, isolation, and recovery (FDIR) is a subfield of control engineering which concerns itself with monitoring a system, identifying when a Fault (technology), fault has occurred, and pinpointing the type of fault and its location. Two ...
References
External links
Gate-level fault simulator PROOFS for non-profit educational institutions from the University of Illinois
Electronic design
Electronic design automation
Electronic engineering
Integrated circuits