300 likes | 383 Views
Substantial Fault Pairs at-A-Time (SFPAT): An Automatic Diagnostic Pattern Generation Method. Jing Ye 1,2 , Xiaolin Zhang 1,2 , Yu Hu 1 , and Xiaowei Li 1 1 Key Laboratory of Computer System and Architecture Institute of Computing Technology Chinese Academy of Sciences
E N D
Substantial Fault Pairs at-A-Time (SFPAT):An Automatic Diagnostic Pattern Generation Method Jing Ye1,2, Xiaolin Zhang1,2, Yu Hu1, and Xiaowei Li1 1Key Laboratory of Computer System and ArchitectureInstitute of Computing Technology Chinese Academy of Sciences 2Graduate University of Chinese Academy of Sciences
Motivation Fault Diagnosis Quality Distinguishability of Used Patterns Efficiency of Diagnosis Method Distinguish as Many Fault pairs as possible Few More Patterns Than Test Patterns
Outline • Key Observation • Distinguishability of 1-detect compressed Test Patterns • Distinguishability of N-detect Test Patterns • Related Work • Proposed Diagnostic Pattern Generation Method • Diagnostic Pattern Generation Method Overview • Circuit Transformation and Fault List Creation • Diagnostic Pattern Generation Flow • Experimental Result • Experimental Setting
Key Observation Distinguishability of 1-Detect Compressed Test Patterns • Experiment Setting • ISCAS’89 benchmark circuits • 1-detect compressed test patterns (TetraMax Ver.A-2007.12) • Fault Pairs Classification FP1 type FP2 type FP3 type two faults in the fault pair are in different FFRs but with the same observation points. two faults in the fault pair are in the same FFR. two faults in the fault pair are in different FFRs but with at least one different observation points. qp qp qp p Fanout Free Region (FFR)
Key Observation Distinguishability of 1-Detect Compressed Test Patterns Percentage of FPi-type fault pairs among all the fault pairs FP3 type FP3 type FP2 type FP2 type Percentage of indistinguishable FPi-type fault pairs among all the indistinguishable fault pairs AVERAGE FP1 type FP1 type
Key Observation Distinguishability of 1-Detect Compressed Test Patterns • FP1 type fault pairs • Two faults in the fault pair are in the same FFR • FP2 type fault pairs • Two faults in the fault pair are in different FFRs but with the same observation points • FP3 type fault pairs • Two faults in the fault pair are in different FFRs but with at least one different observation point AVERAGE FP1 > FP2 > FP3 ‘>’ : harder to be distinguished
Key Observation Distinguishability of 1-Detect Compressed Test Patterns • FP1 type fault pairs • Two faults in the fault pair are in the same FFR • FP2 type fault pairs • Two faults in the fault pair are in different FFRs but with the same observation points • FP3 type fault pairs • Two faults in the fault pair are in different FFRs but with at least one different observation point AVERAGE FP1 > FP2 > FP3 ‘>’ : harder to be distinguished +
Key Observation Distinguishability of N-Detect Test Patterns • N-detect test pattern • A fault may be detected for multiple times in different ways. FP1 type fault pairs
Related Work • Test elimination process of modifying test patterns • [I. Pomeranz, S. M. Reddy TCAD2000] • [I. Pomeranz, S. M. Reddy ETS2007] • Exclusive test pattern generation • [V. D. Agrawal, D. H. Baik, et al. ICVD2003] • Pattern generation for fault-tuple modeled faults • [N. K. Bhatti, R. D. Blanton ITC2006] • Integer linear program formulation • [M. A. Shukoor, V. D. Agrawal ETS2009] • Pattern distinguishability and N-detect patterns • [Z. Wang, M. Marek-Sadowska, et al. ICCD2003] • Pattern reordering algorithm for truncated fail data • [C. Gang, S. M. Reddy, et al. DAC2006]
Proposed Diagnostic Pattern Generation Method Diagnostic Pattern Generation Method Overview
Proposed Diagnostic Pattern Generation Method Diagnostic Pattern Generation Method Overview
Proposed Diagnostic Pattern Generation Method Diagnostic Pattern Generation Method Overview
Proposed Diagnostic Pattern Generation Method Diagnostic Pattern Generation Method Overview Cont.
Proposed Diagnostic Pattern Generation Method Circuit Transformation and Fault List Creation • Miter circuit • Miter circuit is a circuit consisting of two modified duplication D1 and D2 of the original circuit. • Different connection of D1 and D2 is proposed in previous works. • S-fault • The pattern which can detect a S-fault in the transformed circuit can distinguish its related fault pair in the original circuit. • Example • Stuck-at v fault at l: l/v. • We will work on other fault models in the future. • Distinguish the fault pair (a/1,c/1) and the fault pair (b/1,d/1).
Proposed Diagnostic Pattern Generation Method Circuit Transformation and Fault List Creation • Target fault pair • (a/1,c/1) • (b/1,d/1) • SA1-module • ‘out’ = ‘sel’ | ‘in’
Proposed Diagnostic Pattern Generation Method Circuit Transformation and Fault List Creation • Target fault pair • (a/1,c/1) • (b/1,d/1) • SA1-module • ‘out’ = ‘sel’ | ‘in’
Proposed Diagnostic Pattern Generation Method Circuit Transformation and Fault List Creation • Target fault pair • (a/1,c/1) • (b/1,d/1) • SA1-module • ‘out’ = ‘sel’ | ‘in’
Proposed Diagnostic Pattern Generation Method Circuit Transformation and Fault List Creation • Target fault pair • (a/1,c/1) • (b/1,d/1) • SA1-module • ‘out’ = ‘sel’ | ‘in’ • S-fault • sel1/1 – (a/1,c/1) • sel2/1 – (b/1,d/1)
Proposed Diagnostic Pattern Generation Method Circuit Transformation and Fault List Creation • Target fault pair • (a/1,c/1) • (b/1,d/1) • SA1-module • ‘out’ = ‘sel’ | ‘in’ FAULT-FREE 0 0 FAULT-FREE • S-fault • sel1/1 – (a/1,c/1) • sel2/1 – (b/1,d/1)
Proposed Diagnostic Pattern Generation Method Circuit Transformation and Fault List Creation • Target fault pair • (a/1,c/1) • (b/1,d/1) • SA1-module • ‘out’ = ‘sel’ | ‘in’ INJECT a/1 1 INJECT c/1 • S-fault • sel1/1 – (a/1,c/1) • sel2/1 – (b/1,d/1)
Proposed Diagnostic Pattern Generation Method Circuit Transformation and Fault List Creation • Target fault pair • (a/1,c/1) • (b/1,d/1) • SA1-module • ‘out’ = ‘sel’ | ‘in’ INJECT h/1 0 0 FAULT-FREE • S-fault • sel1/1 – (a/1,c/1) • sel2/1 – (b/1,d/1) • Fault in original circuit • Constrain the value of sel to 0
Proposed Diagnostic Pattern Generation Method Diagnostic Pattern Generation Flow FP1 > FP2 > FP3
Proposed Diagnostic Pattern Generation Method Diagnostic Pattern Generation Flow
Proposed Diagnostic Pattern Generation Method Diagnostic Pattern Generation Flow SAT tool
Experimental Result Experimental Setting • Benchmark circuit • ISCAS’89 • ITC’99 • Test Pattern • TetraMax Ver.A-2007.12 • 1-detect compressed test patterns
Experimental Result Experimental Data The number of S-faults is mainly determined by the circuit structure The number of S-faults becomes much smaller
Experimental Result Comparison with Previous Work • Comparison with [12] • ISCAS’89: almost the same for the small circuits • ITC’99: different version of benchmark circuits [12] I. Pomeranz and S. M. Reddy, "Diagnostic Test Generation Based on Subsets of Faults," Proc. of European Test Symposium (ETS), pp. 151-158, 2007.
Number of test patterns in this work Number of diagnostic patterns in [12] Number of test patterns in [12] About 90% of distinguished fault pairs under diagnostic patterns among indistinguished fault pairs under test patterns in [12] Number of diagnostic patterns in this work Experimental Result 100% in this work Comparison with Previous Work • Comparison with [12] [12] I. Pomeranz and S. M. Reddy, "Diagnostic Test Generation Based on Subsets of Faults," Proc. of European Test Symposium (ETS), pp. 151-158, 2007.
Conclusion Distinguishability of patterns are important ! • Distinguishability of 1-detect compressed test patterns • FP1 > FP2 > FP3 • Miter-circuit and S-fault • The pattern which can detect a S-fault in the miter-circuit can distinguish its related fault pair in the original circuit. • There is no need to modify the ATPG tool, and the functions of ATPG tool can also be applied.
Thank You for Your Attention ! • Any Questions?