1,721,400 research outputs found
Functional verification of a multiple-issue, pipelined, superscalar Alpha processor - the Alpha 21164
No full textDigital's Alpha 21164 processor is a complex quad-issue, pipelined, superscalar implementation of the Alpha architecture. Functional verification was performed on the logic design and the PALcode interface. The simulation-based verification effort used implementation-directed, pseudorandom exercisers, supplemented with implementation-specific, hand-generated tests. Extensive coverage analysis was performed to direct the verification effort. Only eight logical bugs, all unobtrusive, were detected in the first prototype design, and multiple operating systems were booted with these chips in a prototype system. All bugs were corrected before any 21164-based systems were shipped to customers
Benchmark Tests On The Digital Equipment Corporation Alpha Axp 21164-Based Alphaserver 8400, Including A Comparison Of Optimized Vector And Superscalar Processing.
Get PDF: This paper reports single-processor performance of the DEC 8400 system, a multi-cpu mainframe based on the DEC 21164 microprocessor. Performance is compared with single processors of the CRAY J90, the IBM RISC System/6000 Model 39H, and the SGI Power Onyx (75 MHz MIPS R8000). Benchmark codes representing Los Alamos applications with a range of computational characteristics were used. An important part of the comparison uses a particle transport application with two implementations, one that is highly vectorized and one that is unvectorizable with memory access patterns more suitable for superscalar processors. The results suggest that the best architecture /implementation match is the vectorizable code running on the vector processor. Introduction The second generation of the Digital Equipment Corp. (DEC) Alpha AXP microprocessor is referred to as the 21164. An important difference between it and its predecessor, the 21064, is that the 21164 has twice the multiply/add throughput pe..
Testability Features and the Testability Access of the Alpha 21164 Microprocessor
No full textThis paper summarizes the testability features of the Alpha 21164 microprocessor chip and desribes the design of the special test ports employed for accessing them. 1. Introduction The Alpha 21164 microprocessor is a superscalar implementation of Digital's Alpha architecture [1-3]. It is designed to meet the requirements of a wide variety of systems ranging from uniprocessor workstations to multiprocessor supercomputers. At a 300 MHz operating frequency, it is the industry's first microprocessor to achieve greater than one billion instructions per second peak performance. Table 1 summarizes some key characteristics of the microprocessor. Table 1: Chip Summary Transistors: 9.3 M Power: 50W Die: 16.5mmX18.1mm Frequency: 300 MHz Process: 0.5µm; 0.35 µm L eff 4-layer Metal Performance: . 1.2 BIPS (peak) Package: 499-pin ceramic PGA w/ slug . 330 SPECint (est) . 500 SPECfp (est) Voltage: 3.3V; 5V I/O compatible . 600 TPS (est) Figure 1 shows a top level block diagram of the ..
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Etude des Architectures des Microprocesseurs DEC 21164, IBM POWER2 et MIPS R8000
Get PDFAujourd'hui, les microprocesseurs sont utilisés dans un grand nombre de systèmes matériels~: stations de travail, multiprocesseurs, systèmes temps réels... L'évolution est extrêmement rapide dans ce domaine au niveau de l'intégration sur le circuit intégré, au niveau de la fréquence, au niveau architecture et au niveau du logiciel. Nous étudions dans ce rapport les processeurs DEC 21164, l'IBM Power2 et le MIPS R8000. Effectuée dans le cadre d'une activité de veille technologique, cette étude met en avant les choix faits par les constructeurs et compare les diverses mises en oeuvre
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