A method for reliable measurement of interconnect delays is presented in the paper. The mode of test vectors generation never induces crosstalks. That is why the delay measurement is reliable. Also, ...minimization of ground bounce noises and reduction of power consumption during the test is an additional advantage. The presented method allows also localizing and identifying static faults of both stuck-at (SaX) and short types. The paper deals with the hardware that is necessary for implementing the method. The techniques for test data compression, that allow substantial reduction of data volume transferred between SoC and ATE, are also proposed.
The paper presents a novel method for size reduction of a signature-based diagnostic dictionary that is used in testing of static and delay faults in connections by means of specific Interconnect ...BIST (IBIST) structure. The IBIST has a form of a ring register R-LFSR which feedback lines constitute connections under test. The previous studies of the authors assumed implementation of a single 2n-bit R-LFSR structure for testing and diagnosis of faults occurring in buses with the width n ≤ 32 bits. As size of the diagnostic dictionary rapidly grows in pace with both the number of connections under test and increase of the fault-multiplicity, it was a significant drawback that hindered examination of very wide buses. This study proposes how to solve this problem by splitting the n-bit bus into b fragments with the width of k bits each. Every fragment is tested by an independent R-LFSR register with its length of 2 k bits. The study assumes faults with the maximum fault-multiplicity r max = 3 for each k-bit fragment of the bus, where the faults present combinations of stuck-at 0/1, AND /OR shorts of two or three lines and delay faults. The proposed approach has made it possible to significantly reduce size of the signature-based diagnostic dictionary that is necessary to locate and identify the mentioned faults. It was achieved by substantial reduction of the number of signature entries covered by the dictionary as well as by shortening the length of the signatures by b times. Moreover, the newly developed method enables to locate and identify substantial part of faults for the entire bus with the width of n, where the multiplicity of faults can be even as high as b r max .
A new structure of the fast and low-area test pattern generator (TPG) based on a long linear register composed of T-type flip-flops that can be easily integrated with the scan path is proposed for a ...BIST in the paper. In addition, authors propose a testing method that is suitable for verifying correct functioning of both the scan-path and the new type TPGs incorporated in it.
The paper highlights the need to apply the test-per-clock method at full clock rates to test crosstalks in networks of long interconnections between modules in a System on a Chip (SoC). The proposed ...method of testing n-interconnects involves the 3n-R-LFSR (ring linear feedback shift register) with a polynomial that guarantees the long counting cycle. The part of the ring LFSR that generates test patterns has double number of flip-flops where every second flip-flop is connected to the network of interconnections under test. It has been proved that the 3n-R-LFSR register is capable to generate all the two-test patterns that are necessary for the network with n interconnections. The completed simulation experiments evidenced efficiency of the method application to test crosstalks that are manifested by either an glitch or an edge delay.
The problem of knowledge-base updating is addressed from an abstract point of view in the attempt to identify some general desiderata the updating mechanism should satisfy. They are recognized to be ...basically two: evaluating the local impact of new data on the single items of knowledge already stored, and propagating this effect through the knowledge-base maintaining at the same time its global coherence. It will be shown that Bayesian updating, difficult to implement, satisfies simultaneously these two requirements, and that, on the other hand, Dempster—Shafer updating, easy to implement, does not satisfy the requirement of global coherent propagation. I will point out the existence of a trade-off between coherence and effectiveness in the methods for representing uncertainty currently proposed in AI. Two kinds of learning machines, Boltzmann machines and Harmonium, will be discussed and considered as first attempts to give a non-behavioral characterization of coherence in a cognitive agent, a characterization still consistent with the behavioral (probabilistic) definition.
Generalized Bayesian conditionals and Dempster-Shafer's conditionals are considered as probabilistic kinematics which hold under different conditions. In particular, generalized Bayes can be applied ...whenever the available evidence allows to partition the frame of reference. It will be pointed out how, in this case, it is always possible to get a probability function by a belief function by means of minimum (relative) entropy kinematics.
A theory of initialising new type linear test pattern generators (TPGs) based on rule 60 Cellular Automata (register composed of T-type flip-flops only) is developed in the paper. Two practical ways ...of setting an initial state of such registers are also shown. One of them is based on the use of external tester while another one is well suited to BIST applications. They both involve much less area overhead than hitherto employed TPG initialisation techniques, which require using either T-type flip-flops with set or reset inputs or T-type flip-flops equipped with scan mode.
The paper introduces a novel idea of interconnect fault detection, localization and identification based on test response compaction using a MISR. The above-mentioned operations are made at-speed. ...The localization is done by means of three long, full diagnostic resolution sequences: Walking 1 (W1), Walking 0 (W0) and a part of Johnson sequence (J). The final fault identification phase exploits information stored in two or three signatures
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