Frontier fault model we consider all multiple faults consisting of all combinations of the above faults excluding simultaneous faults on gate inputs. Request pdf on diagnosing multiple stuckat faults using multiple and single fault. Multiple stuck at faults multiple stuck at fault several single stuck at faults occur at the same time multiple stuck at faults are usually not considered in practice because of two reasons the number of multiple stuck at faults in a circuit with k lines is 3k1, which is too large a number even for circuits of moderate size. Fault modeling electrical engineering and computer science. Many other faults bridging, stuckopen and multiple stuckat are largely covered by stuckat fault tests. Delay fault diagnosis is significantly more difficult than stuck at fault diagnosis as a delay fault model has to consider the size of delay defects and is often harder to define. Transient faults may have permanent effects in fpgas. The classical fault model for a scan test is the single stuckat fault ssf, introduced in 1959 3. The total number of single and multiple stuck at faults in a circuit with k single fault sites is 3k1. Efficient satbased atpg techniques for all multiple stuck. A multiple model based approach for deep space power. Path delay fault pdf and multiple stuckat faultmsaf models uncover defects that are missed by the ssaf model. The undesired outcome is taken as the root top event of a tree of logic.
Single stuck at tests cover a large percentage of multiple stuck at faults. Even when single stuckat fault does not accurately model some physical defects, the tests derived for logic faults are still valid for most defects. Static faults, which give incorrect values at any speed and sensitized by performing only one operation. Nand gate has 3 fault sites and 6 single stuckat faults a b 1 1 z sa0 fault, sa1 fault. Figure 1012 ic with boundary scan register and testaccess port tdi test data input this data is shifted serially into the bsr tck test clock. Fault tree analysis maps the relationship between faults, subsystems, and redundant safety design elements by creating a logic diagram of the overall system.
The fta process is used to solve a wide variety of problems ranging from safety to management issues. The procedure requires insertion of at most modeling gates, when the multiplicity of the targeted fault is. For digital logic single stuckat fault model offers best advantage of tools and experience. Single stuckat fault model other fault models redundancy and. A stuckat fault is a particular fault model used by fault simulators and automatic test pattern generation atpg tools to mimic a manufacturing defect within an integrated circuit. It is shown that the test pattern as for single stuck at fault so for. Architecture fault modeling and analysis with the error. In the faulty circuit, a single linewire is sa0 or sa1.
Apply one clock pulse to the system clock sck to store the new values of qi. Fully testable circuit synthesis for delay and multiple stuck. Subsequent work 29, optimizes the fault simulation without changes in the fault model. This technique allows simulation and test generation for the modeled fault by any single fault simulator or test generator. The simple stuck at fault model paired with a complex fault diagnosis algorithm is compared against the bridging fault model paired with a simple fault diagnosis algorithm to determine which. This technique allows simulation and test generation for the modeled fault by any singlefault simulator or test generator. The fault tree analysis is provided in visualxsel 12. It is definitely better if all combinations of multiple faults can be completely tested.
One of the most common heavy problems in fault detection and fault diagnosis is the fault masking. Modelbased fault detection, isolation, and reconfiguration fault detection isolation, and reconfiguration fdir is a critical component of system resiliency, in particular for. We show that the multiple stuckat fault test set can be derived from the disjoint sum of product expression which allows test pattern generation at design time, eliminating the need of an atpg after the synthesis stage. Multiple stuckat fault testability analysis of robdd based. Multiple faults have been considered as very difficult since a mline circuit. Multiple stuckfault msf model is a straightforward extension of the ssf model in which several lines can be simultaneously stuck. Fully testable circuit synthesis for delay and multiple. In the faulty circuit any subset of wires are sa0sa1. Delay fault diagnosis is significantly more difficult than stuckat fault diagnosis as a delay fault model has to consider the size of delay defects and is often harder to define. On diagnosing multiple stuckat faults using multiple and single fault.
Some definitions why modeling faults various fault models. Pdf selection of a fault model for fault diagnosis based on. Identifying untestable transition faults in latch based designs with multiple clocks manan syal, sreejit chakravarty and michael s. Let f be the set of stuckat faults s1 and s0, where s. A multiple stuck at fault model through this conversion when a fault is not activated the output of the ingate circuit is same as good circuit value.
Many different physical defects may be modeled by the same logical stuck at fault. Identifying untestable transition faults in latch based. Multiple stuckat fault testability analysis of robdd. The first one is a free positioning of the ftaelements. The total number of single and multiple stuckat faults in a circuit with k single fault sites is 3k1. Multiple stuckmultiple stuck at faultsat faults a multiple stuck at fault means that any set of lines is stuck at some combination of 0,1 values. Design error diagnosis in digital circuits with stuckat. Later, the work 30 extends this to multiple and single stuck at faults, and a subset of single event upset seu limited to registers, hampering fault injection inside combinatorial circuits. We show that the multiple stuck at fault test set can be derived from the disjoint sum of product expression which allows test pattern generation at design time, eliminating the need of an atpg after the synthesis stage. Citeseerx document details isaac councill, lee giles, pradeep teregowda.
Ssf is technology independent s has been successfully used on ttl, ecl, cmos, etc. Figure 104 example network for stuckat fault testing. Similarly it can be proved for other signal lines also. Single stuckat faults at the clbs poles and multiple faults constituted from such single stuckat faults are considered. Multiple stuck fault msf model is a straightforward extension of the ssf model in which several lines can be simultaneously stuck. Causeeffect analysis 2 4 starts from possible causes fault models. C sa0, x sa1 x how many msl fault can there be in a circuit with n nodes. The second attack considers the cipher with a secret sbox. Charles kim, lecture notes on fault detection and location in distribution systems, 2010. It provides a standardized discipline to evaluate and control hazards. Stuckat fault as a logic fault zstuckat fault is a functional fault on a boolean logic function implementation zit is not a physical defect model stuckat 1 does not mean line is shorted to vdd stuckat 0 does not mean line is grounded.
For example, an input is tied to a logical 1 state during test generation to. The application of this model in circuit optimization, fault diagnosis and testing of multiply testable faults is discussed with examples. Efficient satbased atpg techniques for all multiple stuckat. We then characterize frontier faults which are equivalent to all multiple faults. The application of this model in circuit optimization, fault diagnosis and testing of multiply testable faults is discussed. Intel architecture group, intel corporation, santa clara, ca. Hsiao bradley department of electrical and computer engineering, virginia tech, blacksburg, va. Pdf modelling stuckat faults in combinational circuits with. Pdf on diagnosing multiple stuckat faults using multiple and. For most other fault models for example stuckat faults, the standard requires that. Download pdf download citation view references email request permissions.
Multiple stuckmultiple stuckat faultsat faults a multiple stuckat fault means that any set of lines is stuckat some combination of 0,1 values. Memory and analog circuits need other specialized fault models and tests. The proposed cuit using stuckat fault modelbased simulation and arrive at a poten. Independent of the testing scheme that is employed to detect transition faults, if the initial sequence t1 or the final test sequence t2 cannot be generated for a particular. Individual signals and pins are assumed to be stuck at logical 1, 0 and x. Multiple transient fault and multiple upset modeling the problem of the impact of multiple transient faults occurring simultaneously has been addressed in the past, but with the focus on memories 1718, in the light of the multiple upsets resulting from a single transient phenomenon. Gunda 10 proposed a scheme to handle multiple stuck at faults by ranking the faults according to the likelihood of being present in the defective part. Basically, in this model a single line is erroneously stuckat 0 or stuckat 1. Architecture fault modeling and analysis with the error model. Many other faults bridging, stuckopen and multiple stuck. Single stuckat fault model other fault models redundancy. The single stuck at fault has previously being used for modeling path delay faults 4. A systematic approach for diagnosing multiple delay faults.
Fault analysis procedure the stuckat fault model, which has been successfully and most commonly used for decades, is a logical and easytounderstand fault model. Gate arrays, standard cell, custom vlsi even when single stuckat fault does not accurately model some physical defects, the tests derived for logic. Given a set of input vectors, our objective is to determine the set of multiple stuckat01 sa01 faults that are not present in the circuit under test cut. Abstract multiple stuck at fault model analysis submitted. The definitions for each of these types of faults can be found in section 1 of the iso standard3. This paper presents a new approach to multiple fault analysis. Fault universe is too large, msl fault model seldom used, especially since tests for ssl faults cover many msl. Testability challenges in any synthesis approach include complete fault e ciency and ease of. Abstract a new method to fault diagnosis in combinational circuits is presented. Stuckat fault model can detect many realistic physical faults. Figure 1011 scan test configuration with multiple ics. Fault model summary fault models are analyzable approximations of defects and are essential for a test methodology.
For most other fault models for example stuck at faults, the standard requires that. Table 102 tests for stuckat faults in figure 104 normal gate inputs. Abstract multiple stuck at fault model analysis submitted by. Figure 101 testing and and or gates for stuckat faults. A signal, or gate output, is stuck at a 0 or 1 value, independent of the inputs to the circuit. Modeling and analysis of fault detection and fault tolerance in embedded wireless sensor networks. The process of a stuckat fault model testing is shown in figure 8. It is shown that the test pattern as for single stuckat fault so for. The multiple stuckat fault test set is larger than the single stuckat fault test set. Single stuckat tests cover a large percentage of unmodeled physical defects.
Fault tree analysis fta is a topdown, deductive failure analysis in which an undesired state of a system is analyzed using boolean logic to combine a series of lowerlevel events. Stuckat faults any input or internal wire in circuit can be stuckat1 or stuckat0 single stuckatfault model. A single fault test can fail to detect the target fault if another fault is also present. In a circuit consisting of n lines, a multiple fault is represented by a tuple with at most n components and. Pdf selection of a fault model for fault diagnosis based. The single stuckat fault has previously being used. Many different physical defects may be modeled by the same logical stuckat fault. Multiple stuckat fault models and vlsi diagnostic test. Fault tree analysis fta is one of the most important logic and probabilistic techniques used. Actual number of physical defects in a circuit are too many. Multiple stuck at fault model analysis semantic scholar. Single stuck at faults at the clbs poles and multiple faults constituted from such single stuck at faults are considered. We prove that the modeled circuit is functionally equivalent to the original circuit and the targetedmultiple fault is equivalentto the modeledsingle stuckat fault.
Patternmultiplefaultpropagation which allows to analyze simultaneously bit strings. Fundamental algorithms for system modeling, analysis, and. These faults are based on fault models, and for digital circuits, the main fault models are stuckatfault, bridging fault, and delay fault. This analysis method is mainly used in safety engineering and reliability engineering to understand how systems can fail, to identify the best ways to reduce risk and to determine or get a feeling for event. Modeling and analysis of fault detection and fault tolerance in embedded wireless sensor networks published. Single stuckat tests cover a large percentage of multiple stuckat faults. The multiple stuck at fault test set is larger than the single stuck at fault test set. Gunda 10 proposed a scheme to handle multiple stuckat faults by ranking the faults according to the likelihood of being present in the defective part. The single stuckat faultssaf model is a popular model which covers many defects but not all. Scan out and verify the qi values by pulsing the test clock tck. For example, an input is tied to a logical 1 state during test generation to assure that a manufacturing defect with that type of. Lecture 6 15 pro and con advantages a large number of faults are detected by each pattern when. Fault tree handbook with aerospace applications version 1.
Pdf multiple stuck at fault model analysis semantic scholar. Multiple stuckline msf faults more than one line may be stuck at a logic value a d c b z sa0 sa1 fault. The simple stuckat fault model paired with a complex fault diagnosis algorithm is compared against the bridging fault model paired with a simple fault diagnosis algorithm to determine which. The application of this model in circuit optimization, fault diagnosis and testing of multiply testable faults is. Abstract this paper presents a novel technique to identify. Analysis should classify each of the n faults as safe fault, single point fault spf, residual fault rf, multi point fault mpf, detected fault or latent fault. Moreover additional symbols appear in the icon bar on top, if the menu point data fault tree analysis is used. Multiple stuck at fault analysis is an approach for solving the problem, but the full multiple fault combination analysis is a time consuming procedure. Later, the work 30 extends this to multiple and single stuckat faults, and a subset of single event upset seu limited to registers, hampering fault injection inside combinatorial circuits. Testing digital systems i lecture 6 8 copyright 2010, m. Given a set of input vectors, our objective is to determine the set of multiple stuck at 01 sa01 faults that are not present in the circuit under test cut. A multiple stuckat fault means that any set of lines is. Multiple stuckat faults multiple stuckat fault several single stuckat faults occur at the same time multiple stuckat faults are usually not considered in practice because of two reasons the number of multiple stuckat faults in a circuit with k lines is 3k1, which is. In this paper, we present atpg automatic test pattern generation techniques targeting all multiple stuck at faults, i.
A stuck at fault is a particular fault model used by fault simulators and automatic test pattern generation atpg tools to mimic a manufacturing defect within an integrated circuit. Single stuckat fault three properties define a single stuckat fault only one line is faulty the faulty line is permanently set to 0 or 1 the fault can be at an input or output of a gate example. Ssf is technology independent has been successfully used on ttl, ecl, cmos, etc. Table 102 tests for stuck at faults in figure 104 normal gate inputs a b c d a b p c q r d s t u v w faults tested 0 1 0 1 0 1 0 0 0 1 1 0 1 1 0 1 a1 p1 c1 v1 f1.