Microprocessor Development Research Articles

Let's hear it for audio mining

he Web, databases, and other digitized information storehouses contain a growing volume of audio content. Sources include newscasts, sporting events, telephone conversations, recordings of meetings, Webcasts, documentary archives such as the Visual History Foundation's interviews with Holocaust survivors (http://www.vhf. org), and media files in libraries. Users want to make the most of this material by searching and indexing the digitized audio content. In the past, companies had to create and manually analyze written transcripts of audio content because using computers to recognize, interpret, and analyze digitized speech was difficult. However, the development of faster microprocessors, larger storage capacities, and better speech-recognition algorithms has made audio mining easier. Now, the technology is on the verge of becoming a powerful tool that could help many organizations. For example, companies could use audio mining to analyze customer-service and helpdesk conversations or even voice mail. Law enforcement and intelligence organizations could use the technology to analyze intercepted phone conversations. Public relations firms could use it to analyze news broadcasts to find coverage of clients.

Overview on a formal model of architecture/circuit trade-offs for the implementation of fast processors

Implementation complexity is playing an increasingly important role in the development of high-speed microprocessors, in terms of limitations to the actual cycle time. It is useful for the CPU architecture designer to have an assessment of the achievable cycle time when making architecture design decisions. Formal models exist that allow the designer to have an accurate estimation of the best possible delay of logic units before doing circuit and layout design. The combination of such modeling techniques together with instruction-level cycle-accurate simulation of the CPU architecture can be a powerful tool for the development of fast processors.

An optimal scheduling algorithm for minimizing the computing period of cyclic synchronous tasks on multiprocessors

We present an efficient optimal algorithm that schedules cyclic synchronous tasks into multiprocessors to minimize the computing period of iterative execution. Due to the rapid development of higher speed microprocessors and digital signal processors (DSPs), small-scale parallel embedded systems and on-chip parallel processors with a simple network structure became feasible for applications such as large-scale simulations and computation-intensive plant control systems that were previously executed by massively parallel computers. We consider cyclic synchronous tasks with communication overhead, which run on multiprocessors with a fully connected network. We suggest the computing period as the performance measure to maximize overall computation speed and the individual start policy that allows overlapping different iterations. The concepts and characteristics of the local period and the global period are also introduced. To solve the complex optimal scheduling problem in an efficient way, our algorithm uses a new spatial scheduling technique using the scheduling space which represents all possible start-time schedules in a multi-dimensional space. By using spatial searching and an enhanced branch-and-bound technique, the optimal schedule which minimizes the computing period can be found. The scheduling results for power plant simulation verify the practicality of our algorithm.

Inherently lower-power high-performance superscalar architectures

In recent years, reducing power has become an important design goal for high-performance microprocessors. This work attempts to bring the power issue to the earliest phases of microprocessor development, in particular, the stage of defining a chip microarchitecture. We investigate power-optimization techniques of superscalar microprocessors at the microarchitecture level that do not compromise performance. First, major targets for power reduction are identified within microarchitecture, where power is heavily consumed or will be heavily consumed in next-generation superscalar processors. Then, a new, energy-efficient version of a multicluster microarchitecture is developed that reduces energy the identified critical design points with minimal performance impact. A methodology is developed for energy-performance optimization at the microarchitecture level that generates, for a microarchitecture, a set of energy-efficient configurations, forming a convex hull in the power-performance space. Detailed simulation of the baseline and proposed multicluster architectures has been performed using the developed optimization methodology. A comparison of the two microarchitectures, both optimized for energy efficiency, shows that the multicluster architecture is potentially up to twice as energy efficient for wide issue processors, with an advantage that Grows with the issue width. Conversely, at the same power dissipation level, the multicluster architecture supports configurations with measurably higher performance than equivalent conventional designs.

Fuzzy logic applied to speed control of a stepping motor drive

Nowadays, thanks to the development of microprocessors, stepping motors are widely used in robotics and in the numerical control of machine tools where they have to perform high-precision positioning operations. Nevertheless, the variations of the mechanical configuration of the drive, which are common to these two applications, can lead to a loss of synchronism for high stepping rates. Moreover, the classical open-loop speed control is weak and a closed-loop control becomes necessary. In this paper, the fuzzy logic principle is applied to control the speed of a stepping motor drive with feedback. An advanced test bed is used in order to evaluate the tracking properties and the robustness capacities of the fuzzy logic controller when variations of the mechanical configuration occur. The experiment has been performed using a low-cost 16 bit microcontroller in order to verify the design performance.

Automated environmental monitoring and database management: Fantasies and realities

Modern dataloggers and the ever-increasing number of sensors can measure a wide range of environmental parameters, from air temperature and relative humidity through energy flux density, in minute detail and summarize the data for you at any interval your research requires. The cost of collecting environmental data using automated data recorders and their associated sensors continues to drop with advancements in microprocessor development. The value of the data collected by these systems is largely determined by decisions regarding overall project and individual study component design. The utility and versatility of the information collected is a function of the planning performed at the beginning of the research program. The initial design of the monitoring system and the database produced by the system will determine whether or not the data may be useful for other work being conducted on site or nearby. The expected and actual functionality of the database produced can be quite different depending on the resources applied to the monitoring system during initial setup and with ongoing maintenance. This paper incorporates the experiences gained from three long-term research programs involving extensive automated environmental monitoring networks, the problems encountered, the success stories, and the lessons learned. Suggestions and considerations for system design and database management are proposed. Key words: environmental monitoring, system design, database management

The Diving Response Mechanism and its Surprising Evolutionary Path in Seals andSea Lions

During the last half century or more, studies of diving physiology and biochemistry made great progress in mechanistically explaining the basic diving response of aquatic mammals and birds. Key components of the diving response (apnea, bradycardia, peripheral vasoconstriction, redistribution of cardiac output) were found in essentially all species analyzed and were generally taken to be biological adaptations. By the mid 1970s, this approach to unravelling the diving response had run 'out of steam' and was in conceptual stasis. The breakthrough which gave renewal to the field at this time was the development of microprocessor based monitoring of diving animals in their natural environments, which led to a flurry of studies mostly confirming the basic outlines of the diving response based upon laboratory studies and firmly placing it into proper biological context, underlining its plasticity and species specificities. Now towards the end of the millenium, despite ever more detailed field monitoring of physiology, behaviour and ecology, mechanistic studies are again approaching a point of diminishing returns. To avoid another conceptual stasis, what seems required are new initiatives which we anticipate may arise from two differing approaches. The first is purely experimental, relying on magnetic resonance imaging (MRI) and spectroscopy (MRS) to expand the framework of the original “diving response” concept. The second—evolutionary study of the diving response—is synthetic, linked to both field and laboratory studies. To date the evolution of the diving response has only been analyzed in pinnipeds and from these studies two kinds of patterns have emerged. (1) Some physiological and biochemical characters, required and used in diving animals, are highly conserved not only in pinnipeds but in all vertebrates; these traits are necessarily similar in all pinnipeds and include diving apnea, bradycardia, tissue specific hypoperfusion, and hypometabolism of hypoperfused tissues. (2) Another group of functionally linked characters are more malleable and include (i) spleen mass, (ii) blood volume, and (iii) hemoglobin (Hb) pool size. Increases in any of these traits improve diving capacity. Assuming that conserved physiological function means conserved sequences in specific genes and their products (and that evolving function requires changes in such sequences), it is possible to rationalize both above trait categories in pinniped phytogeny. However, it is more difficult for molecular evolution theory to explain how complex regulatory systems like those involved in bradycardia and peripheral vasoconstriction remain the same through phylogenetic time than it is to explain physiological change driven by positive natural selection.

Predictive Control of an Induction Machine Under an Open Architecture Structure

Due to the rapid innovation speed in the development of microprocessors and communication technology, it becomes necessary to generate software in a hardware-independent way. The consequence of this requirement is the introduction of links between application software and hardware, in an open architecture oriented structure. This paper presents an open architecture structure of motor drives with application to an axis induction machine control, showing the connection between the motor (including load, PWM inverter, current sensors, incremental encoders) and software developments for the end users (automatic design of the tuning parameters, design of the controller), through a DSP based real time part implementation.

Advantages of an Open Architecture Structure for the Design of Predictive Controllers for Motor Drives

Due to the rapid innovation speed in the development of microprocessors and communication technology, it becomes more and more necessary to generate software in a hardware-independent way. The consequence of this requirement is the introduction of a link between application software and hardware, in an open architecture oriented structure. This paper presents an open architecture structure of motor drives control with a particular application to an induction machine axis control, showing the connection between the motor (including load, PWM inverter, current sensors, incremental encoders) and the software developments for the end users (automatic design of the tuning parameters, design of the controller) through a DSP based implementation of the real time part.

Dynamic contact responses of laminated composite plates according to the impactor's shapes

The dynamic contact behaviors of laminated composite plates by a rigid elliptic impactor are discussed. To impose the dynamic contact conditions, the simple laws like the modified Hertz contact law have been used in the early works, but these laws cannot account for a stacking sequence, span or thickness of the laminate, impactor's shape and friction when simulating the dynamic contact behaviors. However, due to the competitive development of cheap powerful microprocessors, the previously prohibitive computing algorithm can be implemented even by the desktop workstations. In this paper, a formulation which can describe the dynamic contact behaviors of composite laminates, precisely, is introduced. A successive iteration method is used for nonlinear analysis and the Newmark method is used for time integration. An algorithm to determine the equilibrium position of a rigid impactor and a composite laminate at each time step is proposed. The effects of the impactor's shape on the quasi-static contact behaviors of isotropic and composite plates are considered. The impact responses of composite laminates due to transverse impact are also presented according to the shape of the impactor. It is concluded, from the computed results of static indentation, that the higher contact force is obtained when the blunter indentor is used, and from the dynamic impact simulation, maximum impact force is elevated and the impact duration is elongated when the shape of impactor is blunter.

Microprocessor architecture design with ATLAS

A concrete example of special purpose microprocessor development demonstrates how this simulation and analysis package facilitates the early stages of design. Simulation data enable the designer to improve performance quickly and easily with less probability of error.

Tuning the Pentium Pro microarchitecture

Designing a wholly new microprocessor is difficult and expensive. To justify this effort, a major new microarchitecture must improve performance one and a half or two times over the previous-generation microarchitecture, when evaluated on equivalent process technology. In addition, semiconductor process technology continues to evolve while the processor design is in progress. The previous-generation microarchitecture increases in clock speed and performance due to compactions and conversion to newer technology. A new microarchitecture must "intercept" the process technology to achieve a compounding of process and microarchitectural speedups. This paper looks at a large microprocessor development project which reveals some of the reasoning (for goals, changes, trade-offs, and performance simulation) that lay behind its final form.

Laryngograph: speech pattern element tools for therapy, training and assessment.

The clinically based, real-time analysis of speech into physically definable elements, which are of direct perceptual and productive importance, has become more readily possible in recent years as the result of microprocessor developments. The combination of the acoustic signal of speech derived from a microphone together with the accompanying Laryngograph signal provides the basis for a highly reliable set of facilities. The paper describes methods and results for the analysis of voice, frication and timbre for both quantitative analysis and teaching and therapy using interactive visual displays. A brief discussion is given of links to work in stroboscopy, electropalatography and the associated use of additional sensors. Finally reference is made to a complete clinical work station combining these different facilities together with the quantitative analytical procedures of the speech pattern audiometer.

Millwrights to mechatronics: The merits of multi-disciplinary engineering

In recent years the term “Mechatronics” has come into use to describe a multi-disciplinary approach to engineering (and particularly engineering design) in which a symbiosis of mechanical, electrical, electronic, computer and software engineering is used to create new design solutions to engineering problems. These mechatronic designs can often be more effective than traditional solutions rooted in mono-disciplinary engineering. This paper notes that virtually all engineering was once the province of millwrights and discusses its division into the many currently recognised constituent, and largely separate, disciplines. It is argued that this has followed from the principles of efficiency through division of production which have long been a tenet of capitalist manufacturing. In the closing two decades of the twentieth century there has been a move to return to more integrated production techniques and, with the development of microprocessors and microprocessor controlled systems and products, a need for integration in engineering design and education. The ways in which microprocessors have been applied to, or embedded in, contemporary products, machines and systems are categorised and examples of the design of mechatronic devices, with which the author has been associated, are presented.

Technology and business: forces driving microprocessor evolution

High-end microprocessors are the epitome of integrated circuit technology. But it is low end microprocessors which fuel progress in microprocessors. More than 98% of the four billion microprocessors forecast to ship worldwide in 1995 will end up in low end embedded applications. The microprocessor industry spends most of its research dollars developing high-end microprocessors for CPU applications. Current high-end microprocessor implementations exploit most of the inherent parallelism in their instruction streams. Where does microprocessor development go from here? I give an overview of the development of the microprocessor industry and I show that to predict where the microprocessor is going one must first understand the industry's illogical behavior.

Partial discharge pulse distribution pattern analysis

Statistical data analysis has been recently requisite for partial discharge (PD) study. This has been enabled by the recent development of microprocessors or the downsizing of computers. It is important to pay more attention to profiles of a packet of PD pulses on the voltage phase angle. Statistical parameters such as skewness and kurtosis have been intensively investigated for PD analysis. More recently, the neural network algorithm has been utilised especially to discriminate PD signals from noise signals for insulation diagnosis.

Reduced-voltage power/performance optimization of the 3.6-volt PowerPC 601 Microprocessor

An experimental 2.0-volt low-power PowerPC 601™ Microprocessor built in a modified 3.6-volt, 0.6-µm IBM CMOS technology is described. By using unmodified tasks from the 3.6-volt design, a 3× power savings was realized while maintaining nearly the original performance. The use of selective scaling provides high performance at reduced power supply voltage. This technique, applicable to selected existing product designs, may allow early entry into the low-power market while minimizing new process development expense. The technique proposes hyperscaled reductions in specific electrical and physical parameters, while keeping horizontal layout rules unchanged. Static chip designs, which comprise the majority of 601 circuitry, respond well to the alterations. In addition, potential reliability detractors are deuced or eliminated. Challenges to this technique include I/O interfacing and minimizing leakages associated with low device thresholds. The 601 design and its base technology are described, a long with the experimental changes. The paper reviews the motivation behind low-power microprocessor development, alternative power-saving techniques being practiced, and opportunities for continued power reduction.

An artificial neural emulator for an odour sensor array

In this paper we describe the development of a stand-alone microprocessor -based instrument which can classify intelligently the signals from an array of odour-sensitive sensors. Data from the odour sensor array are initially used to train a neural net on a PC using a software program and then sent down an RS-232C interface to the artifical neural emulator (ANE). The ANE uses multiplexer and ADC chips to condition the array output, followed by a Motorola 6803-based digital processing stage that contains in its RAM or ROM, an artificial neural architecture, neuronal weights and an operating instruction set. The processor computes the output of a neural network, classifies this against a knowledge base of odours and displays the result on a two-line LCD display. The ANE has also been fused with an array four commercial gas sensors (Figaro Engineering Inc., Japan), a temperature IC and a capacitive humidity sensor to produce a stand-alone intelligent odour-sensing system.

Microprocessors and digital ICs for motion control

This paper reviews the developments in microprocessors and digital ICs with a special attention to applications to motion control. First, the use of microprocessors and digital ICs in the control of electric motor drives is considered. General-purpose microprocessors and microcontrollers are then presented with emphasis on features that are necessary for the implementation of real-time control systems. High-performance advanced processors such as digital signal processors (DSPs), reduced-instruction-set computing (RISC) processors, and parallel processors are studied. Development and debugging tools required for developing sophisticated microprocessor-based control systems are considered. The capabilities of application-specific integrated circuits (ASICs) in motion control and their design process are examined. Typical application examples illustrating research work in digital motion control using microprocessors and digital ICs are presented. The potentials of new devices are considered for application to high-performance drive systems. Trends for future development of the microprocessor technology for motion control applications are projected.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Development of a Portable Microprocessor for Measuring Selected Stress Responses of Growing Pigs

The development of a non-restrictive method for measuring selected stress responses of growing pigs in their environment is important to assess the acceptability of an environment for the pig. Blood pressure, body temperature, and animal activity are three measurements that can relate to stress of an environment. A portable microprocessor-controlled data logger was developed to measure these three parameters every 16 min over several days. These measurements were found to be accurate when obtained from the data logger strapped to a pig. Surgical techniques were developed to obtain blood pressure and body temperature. Specific data collected from this study showed that typical blood pressure for a growing pig (35 kg) is 805 mm Hg, blood temperature varied between 398 C (thermoneutral) and 428 C (surgical recovery) and the pig was active 26% of the time.