11918484
Automatic configuration generation for FPGA interconnect testing
We present a new automatic test configuration generation technique for manufacturing testing of interconnect network of SRAM-based FPGA architectures. The technique guarantees detection of open and bridging faults in all wiring channels and programmable switches in the interconnects. Only 8 test configurations are required to achieve 100% coverage of stuck-open, stuck-closed, open and bridging faults in the interconnects of Xilinx Virtex FPGAs.
2705949
Logic soft errors in sub-65nm technologies design and CAD challenges
Logic soft errors are radiation induced transient errors in sequential elements (flip-flops and latches) and combinational logic. Robust enterprise platforms in sub-65nm technologies require designs with built-in logic soft error protection. Effective logic soft error protection requires solutions to the following three problems: (1) accurate soft error rate estimation for combinational logic networks; (2) automated estimation of system effects of logic soft errors, and identification of regions in a design that must be protected; and, (3) new cost-effective techniques for logic soft error protection, because classical fault-tolerance techniques are very expensive.
18607273
X-tolerant test response compaction
Larger, denser designs lead to more defects; higher quality requirements and new test methods lead to an explosion in test data volume. Test compression technique attempt to do more testing with fewer bits. This article summarizes one such method, X compact which addresses how unknowns the bane of compression and logic BIST techniques are eliminated. DFT engineers must spend serious effort to minimize Xs in future designs. It is impossible to eliminate all Xs. X-tolerant response compactors are necessary for tolerating residual Xs to enable massive compaction with practically no impact on test quality. X-compactors are mainly useful for test compression purposes and provide up to 80 times the test response compaction of traditional scan. X-tolerant signature analyzers extend the X-compact concept to incorporate time compaction, thereby tolerating thousands of Xs and reducing test response data volume by 50 to 2,000 times relative to traditional scan. These signature analyzers are extremely beneficial for BIST because Xs can easily corrupt traditional MISR-based BIST signature analyzers. X-tolerant response compactors also enable efficient diagnosis essential to fast yield-learning.
2397835
Speed clustering of integrated circuits
Experimental data on 0.18 /spl mu/ test chips shows strong evidence of clustering of speeds of neighboring dies on a wafer. This clustering phenomenon is utilized to develop techniques for predicting the speed of a part from the speeds of three or more of its neighbors. On-chip processor monitors are used to further improve the prediction accuracy of these techniques. Experimental data demonstrates both the effectiveness of these prediction schemes and the possibility of applying of them to reduce the cost of speed binning.
2734062
A design diversity metric and reliability analysis for redundant systems
Design diversity has long been used to protect redundant systems against common-mode failures. The conventional notion of diversity relies on "independent" generation of "different" implementations. This concept is qualitative and does not provide a basis to compare the reliabilities of two diverse systems. In this paper, for the first time, we present a metric to quantify diversity among several designs. Based on this metric, we derive analytical reliability models that show a simple relationship between design diversity, system failure rate, and mission time. In addition, we present simulation results to demonstrate the effectiveness of design diversity in Duplex and Triple Modular Redundant (TMR) systems. For independent multiple-module failures, we show that, mere use of different implementations does not always guarantee higher reliability compared to redundant systems with identical implementations-it is important to analyze the reliability of redundant systems using our metric. For common-mode failures and design faults, there is a significant gain in using different implementations-however, as our analysis shows, the gain diminishes as the mission time increases. Our simulation results also demonstrate the usefulness of diversity for enhancing the self-testing properties of redundant systems.
900289
Techniques and algorithms for fault grading of FPGA interconnect test configurations
Conventional fault simulation techniques for field programmable gate arrays (FPGAs) are very complicated and time consuming. The alternative, FPGA fault emulation technique, is incomplete and can be used only after the FPGA chip is manufactured. In this paper, we present efficient algorithms for computing the fault coverage of a given FPGA test configuration. The faults considered are opens and shorts in FPGA interconnects. The presented technique is able to report all detectable and undetectable faults and, compared with conventional methods, is orders of magnitude faster.
3106881
Path vector face routing: geographic routing with local face information
Existing geographic routing algorithms depend on the planarization of the network connectivity graph for correctness, and the planarization process gives rise to a well-defined notion of "faces". In this paper, we demonstrate that we can improve routing performance by storing a small amount of local face information at each node. We present a protocol, path vector exchange (PVEX), that maintains local face information at each node efficiently, and a new geographic routing algorithm, greedy path vector face routing (GPVFR), that achieves better routing performance in terms of both path stretch and hop stretch than existing geographic routing algorithms by exploiting available local face information. Our simulations demonstrate that GPVFR/PVEX achieves significantly reduced path and hop stretch than greedy perimeter stateless routing (GPSR) and somewhat better performance than greedy other adaptive face routing (GOAFR+) over a wide range of network topologies. The cost of this improved performance is a small amount of additional storage, and the bandwidth required for our algorithm is comparable to GPSR and GOAFR+ in quasi-static networks.
29308229
Safety Verification of Model Helicopter Controller Using Hybrid Input/Output Automata
This paper presents an application of the Hybrid I/O Automaton (HIOA) framework [12] in verifying a realistic hybrid system. A supervisory pitch controller for a model helicopter system is designed and then verified. The design of the supervisor is limited by the actuator bandwidth, the sensor inaccuracies, and the sampling rates. Verification is carried out by induction over the length of an execution of the composed system automaton. The HIOA model makes the inductive proofs tractable by decomposing them into independent discrete and continuous parts. The paper also presents a set of language constructs for specifying hybrid I/O automata.
8080205
Using Feature Combination and Statistical Resampling for Accurate Face Recognition Based on Frequency Domain Representation of Facial Asymmetry
This paper explores the efficiency of facial asymmetry in face identification tasks using a frequency domain representation. Satisfactory results are obtained for two different tasks, namely, human identification under extreme expression variations and expression classification, using a PCA-type classifier on a database with 55 individuals, which establishes the robustness of these measures to intra-personal distortions. Furthermore, we demonstrate that it is possible to improve upon these results significantly by simple means such as feature set combination and statistical resampling methods like bagging and random subspace method (RSM) using the same PCA-type base classifier. This even succeeds in attaining perfect classification results with 100% accuracy in some cases. Moreover, both these methods require few additional resources (computing time and power), hence they are useful for practical applications as well and help establish the effectiveness of frequency domain representation of facial asymmetry in automatic identification tasks
206590610
Modeling Phase Spectra Using Gaussian Mixture Models for Human Face Identification
It has been established that information distinguishing one human face from another is contained to a large extent in the Fourier domain phase component of the facial image. However, to date, formal statistical models for this component have not been deployed in face recognition tasks. In this paper we introduce a model-based approach using Gaussian mixture models (GMM) for the phase component for performing human identification. Classification and verification are performed using a MAP estimate and we show that we are able to achieve identification error rates as low as 2% and verification error rates as low as 0.3% on a database with 65 individuals with extreme illumination variations. The proposed method is easily able to deal with other distortions such as expressions and poses, and hence this establishes its robustness to intra-personal variations. A potential use of the method in illumination normalization is also discussed.
35384166
Facial asymmetry quantification for expression invariant human identification
We investigate facial asymmetry as a biometric under expression variation. For the first time, we have defined two types of quantified facial asymmetry measures that are easily computable from facial images and videos. Our findings show that the asymmetry measures of automatically selected facial regions capture individual differences that are relatively stable to facial expression variations. More importantly, a synergy is achieved by combining facial asymmetry information with conventional EigenFace and FisherFace methods. We have assessed the generality of these findings across two publicly available face databases: Using a random subset of 110 subjects from the FERET database, a 38% classification error reduction rate is obtained. Error reduction rates of 45-100% are achieved on 55 subjects from the Cohn-Kanade AU-Coded Facial Expression Database. These results suggest that facial asymmetry may provide complementary discriminative information to human identification methods, which has been missing in automatic human identification.