Digital Electronic Systems Research Articles

A highly sensitive and ultra low‐power forward body biasing circuit to overcome severe process, voltage and temperature variations and extreme voltage scaling

SummaryDynamic voltage scaling is one of the most popular methods used to reduce energy consumption in today's digital electronic systems. However, addressing process, voltage and temperature variations at subthreshold voltages has become an inevitable procedure. Using a variation‐sensitive and ultra low‐power design, this paper proposed a novel technique capable of sensing and responding to process, voltage and temperature variations as well as dynamic voltage scaling by providing an appropriate forward body bias so that energy‐delay product of the whole system was improved. Theoretical analysis for process variation probability, confirmed by post‐layout HSPICE (Synopsys, Inc., Mountain View, CA) simulations for an 8‐bit pipelined Kogge–Stone adder, showed that the circuit performance was enhanced in severe variations and extreme voltage scaling situation. For this adder, for example, assuming a voltage scaling from 0.8 to 0.3 V and temperature changes of −15 to 75 °C, the proposed technique brought about a seven times less delay variation, whereas energy‐delay product improved by 23% compared with a zero body biased adder. Copyright © 2013 John Wiley & Sons, Ltd.

Digital noise produced by a non discretized tent chaotic map

This paper shows a digital electronic system that produces uniformly distributed binary sequences using the inverted tent chaotic map (ITCM) without the scaling and discretization processes. The proposed system has been developed considering a numerical representation of floating point with a 64-bit precision format according to the standard IEEE-754. The proposed system has four important advantages: (i) the produced binary sequences are uniformly distributed and they satisfy 10 randomness tests defined in the NIST 800-22SP guide, (ii) the statistical behavior of the ITCM is not affected by the scaling and discretization processes; therefore, the chaotic map used is not modified, (iii) the statistical behavior of the ITCM does not have stability islands inside the chaotic region, although its control parameter is changed, as it occurs with the logistic chaotic map and (iv) the statistical behavior of the binary sequences is conducted by the control parameter and the skeleton of the bifurcation diagram of the ITCM, which can be considered as the security keys of the system.

Digital System for Acquisition and Processing of Detected Images

The paper presents the digital electronic system for acquisition and processing of images from the detection stage of a compact and high resolution Anger camera to be used in clinical and research environments. Main features of the system are reconfigurability, linearity, low noise and processing data rate through hardware and firmware architecture solutions that also allow the system to operate in the presence of disturbances and electromagnetic noise, while at the same time minimizing the own radiated emissions.

ACCURATE AND EFFICIENT ANALYSIS OF PLANAR ELECTROMAGNETIC BAND-GAP STRUCTURES FOR POWER BUS NOISE MITIGATION IN THE GHZ BAND

Noise reduction in PCB is a major concern in the present digital electronic systems with data rate beyond 10Gbps. The noise, due to simultaneous switching noise, radiation from signal vias crossing the planes, etc. can propagate within parallel plane cavity at its resonant frequencies, thus allowing coupling between integrated circuits (ICs) far from each other. Electromagnetic band-gap (EBG) structures are largely employed as noise reduction technique. This paper presents a quick and e-cient analytical approach for evaluating the EBG noise reduction performances in terms of band-gap limits. The study is based on the physics behavior of the planar EBG structures, focusing on its resonant properties. The resonant modes of the EBG cavity are afiected by the additional inductance of the patterned plane respect to the case of the ideal solid plane cavity. The formulas provided, based on the quantiflcation of such inductance, can be easily implemented and employed for a quick layout design of power planes in multilayer PCBs, as shown in a practical example of a partial EBG plane.

A Kind of Low-cost Non-intrusive Autonomous Fault Emulation System

SRAM-Filed Programmable Gate Arrays (FPGA) have become one of the most important carriers of digital electronic system because of its many inborn advantages. However, as manufacture of Integrated Circuit evolves towards Very Deep Sub-Micron technology, FPGA designers must be careful of circuit’s Single Event Upset (SEU) susceptibility when used in hostile environment, such as avionics and space applications where reliability is vital. We proposed a SEU-fault emulation platform to evaluate circuit’s SEU mitigation performance. The platform does not need any external circuit or micro controller to manage fault emulation process compared with existing approach. Source codes of Circuit Under Test (CUT) do not need to be modified or intruded with any component. It is a non-intrusive testing. Communication between host-computer and emulation board is minimized to accelerate fault injection speed. Experimental result shows that a single fault injecting (including Multi-Bits-Upset) only costs 29us. A circuit state reloading technology is exploited to increase emulation efficiency. Moreover, in the field of evolvable hardware, genetic operations can be reconfigured and its fitness can be evaluated on-line using the proposed fast dynamic reconfiguration method, which is useful for implementing self-repair and self-evolutionary hardware.

Application of FIFO Integrated into FPGA in the Image Acquisition and Storage System

With the scale of digital electronic systems, data transfering in different modules become one the key technology. One common method is to use the handshake signal.This method is not only difficult to implement, but also needs to consider the speed of the both sides’ clock. In response, t the article puts forward a design of FIFO integrated into FPGA, which has been applied to the image acquisition and storage system. The interior resources of FPGA have been fully used and the system design has been simplified yet.

A field-programmable-gate-array-based high-speed transceiver for a quartz crystal microbalance induced bond-rupture sensor

There is a need for faster and more precise biosensors to identify a disease in medical diagnostics. Bond-rupture scanning is a new sensor technique by inducing antibody–antigen bonds to rupture from a transducer surface. A quartz crystal microbalance (QCM) oscillates horizontally, and can be used as a platform to measure the mass change on its surface. A high speed digital electronics system was demonstrated for the purposes of inducing and detecting bond rupture. A field-programmable-gate-array-based high speed transceiver board is controlled by a digital signal processor, as well as various graphical user interfaces for the end user interaction. Bond-rupture detection was carried out by rupturing modified beads as a biological element shaking off from the surface of a QCM. It took as little as 20 s in a scanning experiment. The advantages of the proof-of-concept QCM and bond-rupture detection are that it is quick, simple and capable of discriminating between specific and non-specific interactions.

Suprapatellar versus Infra-Patellar Intramedullary Nail Insertion of the Tibia: A Cadaveric Model for Comparison of Patellofemoral Contact Pressures and Forces

To quantify patellofemoral contact pressures and forces during infrapatellar (IP) and suprapatellar (SP) intramedullary tibial nail insertion. Fresh-frozen hemicadavers with intact lower extremities and pelves were used for this study. A standard IP entry portal was used on nine tibiae, whereas an SP entry portal was used in eight tibiae. A digital electronic pressure sensor system was used to dynamically measure peak pressures within the patellofemoral joint during each procedure. Data were continuously recorded from the start to completion of each procedure. Mean pressure and force as well as peak contact pressures recorded were then compared between the two techniques. Mean patellofemoral pressures and forces as well as peak contact pressures were higher in the SP group than the IP group. The mean peak contact pressure was 0.90 MPa (range, 0.48-1.26 MPa) during IP nailing. The mean peak contact pressure on the patella and femoral condyles was 1.84 MPa (range, 1.09-2.95 MPa) and 2.13 MPa (range, 1.10-2.86 MPa), respectively, during SP nailing. It is known that structural integrity of articular cartilage is compromised at impact loads exceeding 25 MPa, and chondrocyte apoptosis can occur at sustained loads of as little as 4.5 MPa in immature bovine cartilage. The results of this study indicate that although the patellofemoral contact pressures are higher with SP nail insertion, they remain below the values reported to be detrimental to articular cartilage. Based on these data, we do not believe that the SP entry portal poses a significant risk to the viability or structural integrity of the articular cartilage of the patellofemoral joint. Clinical correlation is needed.

Ocultamiento del Mensaje de Señales de Voz usando la Transformada de Ondita Haar Discreta

This work introduces a message concealment method for voice signals transmission using codification through multi-resolution filter banks implementation for analysis and synthesis for the Discrete Haar Wavelet Transform. Through these multi-resolution filter banks of Haar wavelet the voice signal can be split in its components, and later a reversible distortion of the synthesis of its multi-resolution component signals is made, obtaining an output signal that, although maintains the same information of the original input signal, hides the message of the carried voice signal in itself. This method can be applied in codified transmission of voice, analog or digital signals, and due to the simplicity of the method it’s suitable to be implemented on digital electronic systems like FPGA, or ASIC.

Improving Digital System Diagnostics Through Prognostic and Health Management (PHM) Technology

This paper presents work on the development of a robust online digital electronic health management system. The presented technical approach integrates collaborative diagnostic and prognostic techniques from engineering disciplines, including statistical reliability, damage accumulation modeling, physics-of-failure modeling, signal processing and feature extraction, and automated reasoning algorithms. The prognostic and health management (PHM) approach is based on a paradigm of minimally invasive onboard monitoring paired with model-based estimates to deliver timely and accurate health assessments.

An introduction to I2C and SPI protocols

Today, at the low end of the communication protocols we find the inter-integrated circuit (I <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> C) and the serial peripheral interface (SPI) protocols. Both protocols are well suited for communications between integrated circuits for slow communication with on-board peripherals. The two protocols coexist in modern digital electronics systems, and they probably will continue to compete in the future, as both I <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> C and SPI are actually quite complementary for this kind of communication.

Microprocessor design using hardware description language

The following paper has been conceived to deal with the contents of some lectures aimed at enhancing courses on digital electronic, microelectronic or VLSI systems. Those lectures show how to use a hardware description language (HDL), such as the VHDL, to specify, design and verify a custom microprocessor. The general goal of this work is to teach how to handle the design of a complete digital system, using a commercially important HDL, from specification to testing. From a pedagogical point of view, this is very important since it helps students get used to a design flow commonly accomplished within semiconductors and microelectronics industries.

Superconductor Digital-RF Receiver Systems

Digital superconductor electronics has been experiencing rapid maturation with the emergence of smaller-scale, lower-cost communications applications which became the major technology drivers. These applications are primarily in the area of wireless communications, radar, and surveillance as well as in imaging and sensor systems. In these areas, the fundamental advantages of superconductivity translate into system benefits through novel Digital-RF architectures with direct digitization of wide band, high frequency radio frequency (RF) signals. At the same time the availability of relatively small 4K cryocoolers has lowered the foremost market barrier for cryogenically-cooled digital electronic systems. Recently, we have achieved a major breakthrough in the development, demonstration, and successful delivery of the cryocooled superconductor digital-RF receivers directly digitizing signals in a broad range from kilohertz to gigahertz. These essentially hybrid-technology systems combine a variety of superconductor and semiconductor technologies packaged with two-stage commercial cryocoolers: cryogenic Nb mixed-signal and digital circuits based on Rapid Single Flux Quantum (RSFQ) technology, room-temperature amplifiers, FPGA processing and control circuitry. The demonstrated cryocooled digital-RF systems are the world's first and fastest directly digitizing receivers operating with live satellite signals in X-band and performing signal acquisition in HF to L-band at ∼30GHz clock frequencies.

On the Evolution of Remote Laboratories for Prototyping Digital Electronic Systems

The design of digital electronic systems for industrial applications can benefit in many ways from the prototyping capabilities of field-programmable gate array (FPGA) platforms. This paper presents three evolutionary releases of an FPGA-based remote laboratory and discusses the didactical and technical motivations behind each release, aiming to reduce the overhead of setting up and operate a laboratory environment where designers and students can use FPGA prototyping to validate their designs. To achieve that, a number of abstraction layers were introduced, allowing configuration and data processing in remote FPGA platforms, as well as integrating such platforms within a simulation environment. The proposed approach supported a number of projects where groups of designers and students could specify, refine, and prototype electronic systems using a pool of remotely available FPGA platforms.

Mid-infrared digital electronic camera system for assessing natural resources

Water strongly absorbs mid-infrared (1300-2500 nm) radiation, resulting in this region of the spectrum being sensitive to the water content within features. Little information is available on using an electronic digital camera filtered to this region of the spectrum to assess natural resources. The objectives of this study were to assemble an electronic digital camera system obtaining mid-infrared imagery and to show practical applications of the system for assessing natural resources. The system consists of a near-infrared to mid-infrared light sensitive camera (900-1700 nm, 14-bit radiometric resolution) containing a 640 by 512 indium gallium arsenide area array, a computer, an image acquisition card, a camera-link cable, a keyboard, a color monitor, a camera tripod, a generator, a camera mount, and a mid-infrared narrow bandpass filter (1632-1648 nm). The components of the system allow users to obtain ground or airborne imagery. Ground-based imagery and data were useful for separating succulent from nonsucculent plant parts. Airborne imagery provided useful information for differentiating vegetation, soil, and water and for identifying management practices such as irrigation. Findings of this study indicate that an electronic digital camera filtered to the mid-infrared region of the optical spectrum has high potential for assessing natural resources.

Fast and direct coupled-micro strip interconnect reduced-order modeling based on the finite-element method

Coupled-microstrip interconnect modeling including frequency-dependent effects (such as skin and proximity effects) is very important in high-speed digital circuits and microwave electronics systems. Two novel methods to model the coupled microstrip with a lumped equivalent circuit are proposed. The circuit model is obtained without using normal mode decomposition. Therefore, the circuit can be used in any excitation. We briefly review the stored energy equation for the inductance and power dissipation for the resistance when the interconnect consists of more than one signal conductor. In the first method, the rational function for impedance has common poles. Thus, an equivalent-circuit model is obtained in a fast and systematic way. In the second method, a more direct way of evaluating series impedance is proposed. Here, a more complicated method of pole selection leads to better accuracy in the frequency domain. A lumped-element equivalent circuit is obtained, which contains only series resistors, series inductors, and shunt capacitors. Hence, the circuit model should be very fast in transient simulation. Three examples are presented to demonstrate and validate the proposed methods.

Seamless aggregation and integration of diverse datastreams: Essential strategies for building practical digital libraries and electronic information systems

In the current information environment, libraries need to leverage on the latest digital technologies as well as the traditional paper technologies towards building practical digital libraries and electronic information systems. Digital libraries built exclusively out of nascent electronic publications such as e-journals, e-books, e-reference works (Web-based training programs, computer-based training programs, etc.), digital scholarly works (monographs, etc. in the public domain) and digitized documents conforming to standard digital formats are proving to be an uphill and unfinished task. Perhaps this could be the major reason why the start-success-finish ratio of most of the digital library initiatives, particularly initiated by isolated/individual libraries, is still left at alarmingly low numbers. We find the motivational and emotional bonding among the stakeholders melting down eventually as the digital library development process gets fired up. There are a host of problems the enthusiastic library fraternity face in their digital library development endeavours starting from copyright issues, technology complexities, infrastructure threats, diverse publication types, multiplicity of digital object formats and above all the publishers’ stringent policies and monopolies. It is therefore essential that the libraries adopt necessary strategies towards developing digital libraries from the lessons learnt. The monolithic and all-in-one-container approach is no longer feasible and no more advocated. It is imperative on the part of the information professional to have a componentized and a multi-system approach to knowledge technologies and information management. Seamless aggregation and meticulous integration of diverse datastreams, embracing the print as well as the electronic information, is the most appropriate strategy to be adopted and applied. This paper shares Indian Institute of Management Kozhikode's experience in creating a state-of-art digital library information system by seamlessly integrating and aggregating the print as well as the diverse and distributed digital content penetrating into its knowledge domain. The paper highlights significant features of IIMK's digital information system—the content aggregation and the content integration strategies we adopted for designing a scholarship Web portal and developing a digital library using the ‘Greenstone’ open source digital library software. The paper also highlights the role of libraries in promoting open access by setting up scholarly institutional repositories (IR). In summary, today's digital library information system is to be seen from a much wider and more holistic perspective, and provided with a much broadened meaning to hold and put together all the print, digital and electronic information available and accessible to the library.

Seamless aggregation and integration of diverse datastreams: Essential strategies for building practical digital libraries and electronic information systems

Summary In the current information environment, libraries need to leverage on the latest digital technologies as well as the traditional paper technologies towards building practical digital libraries and electronic information systems. Digital libraries built exclusively out of nascent electronic publications such as e-journals, e-books, e-reference works (Web-based training programs, computer-based training programs, etc.), digital scholarly works (monographs, etc. in the public domain) and digitized documents conforming to standard digital formats are proving to be an uphill and unfinished task. Perhaps this could be the major reason why the start-success-finish ratio of most of the digital library initiatives, particularly initiated by isolated/individual libraries, is still left at alarmingly low numbers. We find the motivational and emotional bonding among the stakeholders melting down eventually as the digital library development process gets fired up. There are a host of problems the enthusiastic library fraternity face in their digital library development endeavours starting from copyright issues, technology complexities, infrastructure threats, diverse publication types, multiplicity of digital object formats and above all the publishers’ stringent policies and monopolies. It is therefore essential that the libraries adopt necessary strategies towards developing digital libraries from the lessons learnt. The monolithic and all-in-one-container approach is no longer feasible and no more advocated. It is imperative on the part of the information professional to have a componentized and a multi-system approach to knowledge technologies and information management. Seamless aggregation and meticulous integration of diverse datastreams, embracing the print as well as the electronic information, is the most appropriate strategy to be adopted and applied. This paper shares Indian Institute of Management Kozhikode's experience in creating a state-of-art digital library information system by seamlessly integrating and aggregating the print as well as the diverse and distributed digital content penetrating into its knowledge domain. The paper highlights significant features of IIMK's digital information system—the content aggregation and the content integration strategies we adopted for designing a scholarship Web portal and developing a digital library using the ‘Greenstone’ open source digital library software. The paper also highlights the role of libraries in promoting open access by setting up scholarly institutional repositories (IR). In summary, today's digital library information system is to be seen from a much wider and more holistic perspective, and provided with a much broadened meaning to hold and put together all the print, digital and electronic information available and accessible to the library.

Chip devices for miniaturized biotechnology

Chip devices were introduced in chemistry and molecular biology to improve the read-out of information from molecular systems by efficient analytical procedures and to organize automated experiments. Biochips and chip reactor systems are of interest for cellular processes, too, and can be regarded as components in interfaces for the information exchange between living nature and digital electronic systems. In this minireview, different types of chip reactors for biotechnological applications like nanotiterplates, chip thermocyclers and devices for segmented flow operations are discussed. Finally, an outlook is given on the application of chip reactor systems, which are promising tools for automated experiments with highly parallelized screening procedures, for artificial microcompartmentation, cell analogue systems, micro-ecological studies, investigations on modulated morphogenesis, and for a bioanalogue molecular nanotechnology.

Effects of conductor surface condition on signal integrity

The evolution of digital electronic systems to ever‐faster pulse rise times has placed increased demands on printed wiring board (PWB) materials. Signal loss associated with dielectric materials has driven development and commercialization of cost‐effective low loss laminate materials. In order to provide a better understanding of conductor material and surface finish choices, efforts have been made to quantify the impacts of these factors on loss. An alternative test approach has been identified which provides a measure of conductor performance, decoupled from both system geometry and the influence of laminate material.