The memristor-based memory cell design is getting renewed attention in recent years due to its high speed and low power consumption. This paper aims at designing a novel hybrid memory cell incorporating a minimum number of transistors for a rapid bidirectional write operation. The read stability is one of the key elements for high efficiency and superior performance in memory. The memory cell in this paper was designed undertaking adequate measures for maintaining the stability in successive reads without any refresh operation. Extensive simulation experiments were conducted using 32-nm predictive technology model transistors and the results demonstrate superb performance and sound stability of the proposed memory cell in terms of read/write time as well as switching power consumptions.

Test generation for sequential circuits has been a difficult task. This is due to the large search space to be considered in test pattern generation. In this paper the detection of permanent faults in sequential circuits by random testing is analyzed utilizing the circuit partitioning approach together with a continuous parameter Markov model. Given a large sequential circuit, it is partitioned into several smaller partitions using either series or parallel decomposition. For each partition with certain stuck faults specified, the original state table and its error version are derived from an analysis of the partition under fault-free and faulty conditions, respectively. A random testing strategy that uses a three-state Markov model is used for detecting permanent stuck faults. Experimentation on various sequential circuits has shown that a significant saving in testing or test generation time can be achieved if we partition the circuit and then test each of its components as opposed to testing the circuit in its original form.>

In this paper a new method called CACOP For the detection probability analyses of random test patterns is proposed. Considering computational complexity, CACOP is a compromise between O(n/sup 2/) testability analyses like full-range cutting algorithm (FRCA) and linear time testability analyses like the controllability observability program (COP). By propagating bounds of controllabilities and observabilities, CACOP can determine the detection probability lower bound (DPLB) efficiently. The DPLBs derived by CACOP are potentially higher (and thus more accurate) than by FRCA; in addition, CACOP is computationally more efficient than FRCA. The conventional linear time testability analyses cannot guarantee the derivation of DPLBs. On the contrary, CACOP can achieve the goal with tolerable increase in computing complexity.>

General-purpose distributed systems comprised of computing nodes with different characteristics and connected by high-speed communication networks are very popular these days. The development of a dependable distributed system, however, necessitates the use of various techniques including fault tolerance to avert occurrences of failures or system malfunction. The ad hoc techniques of adding redundancy to improve reliability are not always suitable in these circumstances because of excessive design cost. Redundancies have to be allocated at various hardware and software levels in order to optimize their utilization in the system. This paper considers the design of general-purpose fault-tolerant distributed systems based on a layered approach. The benefits of the layered approach in the process of allocation of redundancy and fault tolerance at various system levels are presented and analyzed in the paper.

One of the most important problems in random testing is the measurement of test confidence after a sequence of test vectors has been applied. Sequential statistical analysis is employed to determine the random test confidence. According to the analysis, the random test confidence depends on the detection probability of the circuit under test, the random test length, and the manufacturing yield. A detection procedure driven by a test quality indicator without presumed random test length is proposed based on the results of the sequential statistical analysis. Performance evaluation and simulation results demonstrate that the sequential statistical analysis reflects a better random test confidence than conventional approaches. This difference is due to the fact that conventional test confidence measures do not take the manufacturing yield into account.>

The problem of detecting permanent faults in sequential circuits by random testing is analyzed utilizing a continuous parameter Markov model. Given a sequential circuit with certain stuck faults specified, the original state table and its error version can be readily derived from an analysis of the circuit under fault-free and faulty conditions, respectively. By simulation of these two tables on a computer, the parameters of the desired Markov model can be obtained. The approach does not require formulation of a product state table corresponding to the fault-free state table and its faulty version, which is rather difficult, when dealing with large circuits. For a specified confidence degree, it is easy to derive the parameters of the model and to calculate the required lengths of random test patterns or the maximum testing time. A complete mathematical analysis of the model is given. It provides insight into the nature of faults in relation to random testing and the associated confidence degree.>

It is known from a paper by Das that multiform total symmetry is equivalent to linearity. In this correspondence the results of Das are generalized and a simple proof is given to show that even for multiform partial symmetries the corresponding subfunctions are linear subfunctions.

This note describes an iterative procedure for generating the prime implicants of switching functions by utilizing a new tabular mode of functional representation called clause-column table. The procedure generates all the prime implicants and can be applied equally well to functions given in the sum-of-products or in the product-of-sums froms, both canonical and noncanonical. The procedure can also be readily adapted to determine the prime implicants of functions having a large number of unspecified or DON'T CARE terms.