scholarly journals PGEN: A Novel Approach to Sequential Circuit Test Generation

VLSI Design ◽  
1996 ◽  
Vol 4 (3) ◽  
pp. 149-165 ◽  
Author(s):  
Wen-Ben Jone ◽  
Nigam Shah ◽  
Anita Gleason ◽  
Sunil R. Das

A novel approach, called PGEN, is proposed to generate test patterns for resettable or nonresettable synchronous sequential circuits. PGEN contains two major routines, Sequential PODEM (S-PODEM) and a differential fault simulator. Given a fault, S-PODEM uses the concept of multiple time compression supported by a pulsating model, and generates a test vector in a single (yet compressed) time frame. Logic simulation (included in S-PODEM) is invoked to expand the single test vector into a test sequence. The single test vector generation methodology and logic simulation are well coordinated and significantly facilitate sequential circuit test generation. A modified version of differential fault simulation is also implemented and included in PGEN to cover other faults detected by the expanded test sequence. Experiments using computer simulation have been conducted, and results are quite satisfactory.

Author(s):  
Ahmed K. Jameil ◽  
Yasir Amer Abbas ◽  
Saad Al-Azawi

Background: The designed circuits are tested for faults detection in fabrication to determine which devices are defective. The design verification is performed to ensure that the circuit performs the required functions after manufacturing. Design verification is regarded as a test form in both sequential and combinational circuits. The analysis of sequential circuits test is more difficult than in the combinational circuit test. However, algorithms can be used to test any type of sequential circuit regardless of its composition. An important sequential circuit is the finite impulse response (FIR) filters that are widely used in digital signal processing applications. Objective: This paper presented a new design under test (DUT) algorithm for 4-and 8-tap FIR filters. Also, the FIR filter and the proposed DUT algorithm is implemented using field programmable gate arrays (FPGA). Method: The proposed test generation algorithm is implemented in VHDL using Xilinx ISE V14.5 design suite and verified by simulation. The test generation algorithm used FIR filtering redundant faults to obtain a set of target faults for DUT. The fault simulation is used in DUT to assess the benefit of test pattern in fault coverage. Results: The proposed technique provides average reductions of 20 % and 38.8 % in time delay with 57.39 % and 75 % reductions in power consumption and 28.89 % and 28.89 % slices reductions for 4- and 8-tap FIR filter, respectively compared to similar techniques. Conclusions: The results of implementation proved that a high speed and low power consumption design can be achieved. Further, the speed of the proposed architecture is faster than that of existing techniques.


Author(s):  
Ronald Wilson ◽  
Domenic Forte ◽  
Navid Asadizanjani ◽  
Damon L. Woodard

Abstract In the hardware assurance community, Reverse Engineering (RE) is considered a key tool and asset in ensuring the security and reliability of Integrated Circuits (IC). However, with the introduction of advanced node technologies, the application of RE to ICs is turning into a daunting task. This is amplified by the challenges introduced by the imaging modalities such as the Scanning Electron Microscope (SEM) used in acquiring images of ICs. One such challenge is the lack of understanding of the influence of noise in the imaging modality along with its detrimental effect on the quality of images and the overall time frame required for imaging the IC. In this paper, we characterize some aspects of the noise in the image along with its primary source. Furthermore, we use this understanding to propose a novel texture-based segmentation algorithm for SEM images called LASRE. The proposed approach is unsupervised, model-free, robust to the presence of noise and can be applied to all layers of the IC with consistent results. Finally, the results from a comparison study is reported, and the issues associated with the approach are discussed in detail. The approach consistently achieved over 86% accuracy in segmenting various layers in the IC.


Radiocarbon ◽  
2004 ◽  
Vol 46 (1) ◽  
pp. 455-463 ◽  
Author(s):  
T H Donders ◽  
F Wagner ◽  
K van der Borg ◽  
A F M de Jong ◽  
H Visscher

Sub-fossil sections from a Florida wetland were accelerator mass spectrometry (AMS) dated and the sedimentological conditions were determined. 14C data were calibrated using a combined wiggle-match and 14C bomb-pulse approach. Repeatable results were obtained providing accurate peat chronologies for the last 130 calendar yr. Assessment of the different errors involved led to age models with 3–5 yr precision. This allows direct calibration of paleoenvironmental proxies with meteorological data. The time frame in which 14C dating is commonly applied can possibly be extended to include the 20th century.


2017 ◽  
Vol E100.D (9) ◽  
pp. 2118-2125 ◽  
Author(s):  
Toshinori HOSOKAWA ◽  
Atsushi HIRAI ◽  
Yukari YAMAUCHI ◽  
Masayuki ARAI

Author(s):  
James C.-M. Li ◽  
Michael S. Hsiao

Author(s):  
Meera Day Towler ◽  
Tim Allison ◽  
Paul Krueger ◽  
Karl Wygant

This investigation studies fast-response pressure measurements as an indicator of the onset of surge in a single-stage centrifugal compressor. The objective is to determine an online monitoring approach for surge control that does not rely on surge margin relative to maps from predictions or factory testing. Fast-response pressure transducers are installed in the suction piping, inducer, diffuser, and discharge piping. A speed line is mapped, and high-speed pressure data are collected across the compressor map. The compressor is driven into surge several times to collect pressure data between during surge and between surge events. Following testing, these data are post-processed via filtration and statistical analyses. It is determined that, when taken together, the mean and range of the standard deviation of the time signal for multiple time steps can be used to determine whether the compressor’s operating point is approaching surge for the conditions tested.


Author(s):  
Victoria I. Michalowski ◽  
Denis Gerstorf ◽  
Christiane A. Hoppmann

Aging does not occur in isolation, but often involves significant others such as spouses. Whether such dyadic associations involve gains or losses depends on a myriad of factors, including the time frame under consideration. What is beneficial in the short term may not be so in the long term, and vice versa. Similarly, what is beneficial for one partner may be costly for the other, or the couple unit over time. Daily dynamics between partners involving emotion processes, health behaviors, and collaborative cognition may accumulate over years to affect the longer-term physical and mental health outcomes of either partner or both partners across adulthood and into old age. Future research should move beyond an individual-focused approach to aging and consider the importance of and interactions among multiple time scales to better understand how, when, and why older spouses shape each other’s aging trajectories, both for better and for worse.


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