27 research outputs found

    FPGA Implementation of Double Precision Floating Point Multiplier

    Get PDF
    High speed computation is the need of today’s generation of Processors.  To accomplish this major task,  many functions  are implemented  inside the hardware  of the processor rather than  having  software  computing  the  same  task. Majority of the operations which the processor executes are Arithmetic operations which are widely used in many applications that require heavy mathematical operations such as scientific calculations, image and signal processing. Especially in the field of signal processing, multiplication division operation is widely used in many applications. The major issue with these operations in hardware is that much iteration is required which results in slow operation while fast algorithms require complex computations within each cycle. The result of a Division operation results in a either  in Quotient  and  Remainder  or a Floating  point  number  which is the  major reason  to  make it  more complex than  Multiplication  operation

    Power-Aware Design Methodologies for FPGA-Based Implementation of Video Processing Systems

    Get PDF
    The increasing capacity and capabilities of FPGA devices in recent years provide an attractive option for performance-hungry applications in the image and video processing domain. FPGA devices are often used as implementation platforms for image and video processing algorithms for real-time applications due to their programmable structure that can exploit inherent spatial and temporal parallelism. While performance and area remain as two main design criteria, power consumption has become an important design goal especially for mobile devices. Reduction in power consumption can be achieved by reducing the supply voltage, capacitances, clock frequency and switching activities in a circuit. Switching activities can be reduced by architectural optimization of the processing cores such as adders, multipliers, multiply and accumulators (MACS), etc. This dissertation research focuses on reducing the switching activities in digital circuits by considering data dependencies in bit level, word level and block level neighborhoods in a video frame. The bit level data neighborhood dependency consideration for power reduction is illustrated in the design of pipelined array, Booth and log-based multipliers. For an array multiplier, operands of the multipliers are partitioned into higher and lower parts so that the probability of the higher order parts being zero or one increases. The gating technique for the pipelined approach deactivates part(s) of the multiplier when the above special values are detected. For the Booth multiplier, the partitioning and gating technique is integrated into the Booth recoding scheme. In addition, a delay correction strategy is developed for the Booth multiplier to reduce the switching activities of the sign extension part in the partial products. A novel architecture design for the computation of log and inverse-log functions for the reduction of power consumption in arithmetic circuits is also presented. This also utilizes the proposed partitioning and gating technique for further dynamic power reduction by reducing the switching activities. The word level and block level data dependencies for reducing the dynamic power consumption are illustrated by presenting the design of a 2-D convolution architecture. Here the similarities of the neighboring pixels in window-based operations of image and video processing algorithms are considered for reduced switching activities. A partitioning and detection mechanism is developed to deactivate the parallel architecture for window-based operations if higher order parts of the pixel values are the same. A neighborhood dependent approach (NDA) is incorporated with different window buffering schemes. Consideration of the symmetry property in filter kernels is also applied with the NDA method for further reduction of switching activities. The proposed design methodologies are implemented and evaluated in a FPGA environment. It is observed that the dynamic power consumption in FPGA-based circuit implementations is significantly reduced in bit level, data level and block level architectures when compared to state-of-the-art design techniques. A specific application for the design of a real-time video processing system incorporating the proposed design methodologies for low power consumption is also presented. An image enhancement application is considered and the proposed partitioning and gating, and NDA methods are utilized in the design of the enhancement system. Experimental results show that the proposed multi-level power aware methodology achieves considerable power reduction. Research work is progressing In utilizing the data dependencies in subsequent frames in a video stream for the reduction of circuit switching activities and thereby the dynamic power consumption

    Comparison of logarithmic and floating-point number systems implemented on Xilinx Virtex-II field-programmable gate arrays

    Get PDF
    The aim of this thesis is to compare the implementation of parameterisable LNS (logarithmic number system) and floating-point high dynamic range number systems on FPGA. The Virtex/Virtex-II range of FPGAs from Xilinx, which are the most popular FPGA technology, are used to implement the designs. The study focuses on using the low level primitives of the technology in an efficient way and so initially the design issues in implementing fixed-point operators are considered. The four basic operations of addition, multiplication, division and square root are considered. Carry- free adders, ripple-carry adders, parallel multipliers and digit recurrence division and square root are discussed. The floating-point operators use the word format and exceptions as described by the IEEE std-754. A dual-path adder implementation is described in detail, as are floating-point multiplier, divider and square root components. Results and comparisons with other works are given. The efficient implementation of function evaluation methods is considered next. An overview of current FPGA methods is given and a new piecewise polynomial implementation using the Taylor series is presented and compared with other designs in the literature. In the next section the LNS word format, accuracy and exceptions are described and two new LNS addition/subtraction function approximations are described. The algorithms for performing multiplication, division and powering in the LNS domain are also described and are compared with other designs in the open literature. Parameterisable conversion algorithms to convert to/from the fixed-point domain from/to the LNS and floating-point domain are described and implementation results given. In the next chapter MATLAB bit-true software models are given that have the exact functionality as the hardware models. The interfaces of the models are given and a serial communication system to perform low speed system tests is described. A comparison of the LNS and floating-point number systems in terms of area and delay is given. Different functions implemented in LNS and floating-point arithmetic are also compared and conclusions are drawn. The results show that when the LNS is implemented with a 6-bit or less characteristic it is superior to floating-point. However, for larger characteristic lengths the floating-point system is more efficient due to the delay and exponential area increase of the LNS addition operator. The LNS is beneficial for larger characteristics than 6-bits only for specialist applications that require a high portion of division, multiplication, square root, powering operations and few additions

    Algorithms and architectures for decimal transcendental function computation

    Get PDF
    Nowadays, there are many commercial demands for decimal floating-point (DFP) arithmetic operations such as financial analysis, tax calculation, currency conversion, Internet based applications, and e-commerce. This trend gives rise to further development on DFP arithmetic units which can perform accurate computations with exact decimal operands. Due to the significance of DFP arithmetic, the IEEE 754-2008 standard for floating-point arithmetic includes it in its specifications. The basic decimal arithmetic unit, such as decimal adder, subtracter, multiplier, divider or square-root unit, as a main part of a decimal microprocessor, is attracting more and more researchers' attentions. Recently, the decimal-encoded formats and DFP arithmetic units have been implemented in IBM's system z900, POWER6, and z10 microprocessors. Increasing chip densities and transistor count provide more room for designers to add more essential functions on application domains into upcoming microprocessors. Decimal transcendental functions, such as DFP logarithm, antilogarithm, exponential, reciprocal and trigonometric, etc, as useful arithmetic operations in many areas of science and engineering, has been specified as the recommended arithmetic in the IEEE 754-2008 standard. Thus, virtually all the computing systems that are compliant with the IEEE 754-2008 standard could include a DFP mathematical library providing transcendental function computation. Based on the development of basic decimal arithmetic units, more complex DFP transcendental arithmetic will be the next building blocks in microprocessors. In this dissertation, we researched and developed several new decimal algorithms and architectures for the DFP transcendental function computation. These designs are composed of several different methods: 1) the decimal transcendental function computation based on the table-based first-order polynomial approximation method; 2) DFP logarithmic and antilogarithmic converters based on the decimal digit-recurrence algorithm with selection by rounding; 3) a decimal reciprocal unit using the efficient table look-up based on Newton-Raphson iterations; and 4) a first radix-100 division unit based on the non-restoring algorithm with pre-scaling method. Most decimal algorithms and architectures for the DFP transcendental function computation developed in this dissertation have been the first attempt to analyze and implement the DFP transcendental arithmetic in order to achieve faithful results of DFP operands, specified in IEEE 754-2008. To help researchers evaluate the hardware performance of DFP transcendental arithmetic units, the proposed architectures based on the different methods are modeled, verified and synthesized using FPGAs or with CMOS standard cells libraries in ASIC. Some of implementation results are compared with those of the binary radix-16 logarithmic and exponential converters; recent developed high performance decimal CORDIC based architecture; and Intel's DFP transcendental function computation software library. The comparison results show that the proposed architectures have significant speed-up in contrast to the above designs in terms of the latency. The algorithms and architectures developed in this dissertation provide a useful starting point for future hardware-oriented DFP transcendental function computation researches

    Private and Public-Key Side-Channel Threats Against Hardware Accelerated Cryptosystems

    Get PDF
    Modern side-channel attacks (SCA) have the ability to reveal sensitive data from non-protected hardware implementations of cryptographic accelerators whether they be private or public-key systems. These protocols include but are not limited to symmetric, private-key encryption using AES-128, 192, 256, or public-key cryptosystems using elliptic curve cryptography (ECC). Traditionally, scalar point (SP) operations are compelled to be high-speed at any cost to reduce point multiplication latency. The majority of high-speed architectures of contemporary elliptic curve protocols rely on non-secure SP algorithms. This thesis delivers a novel design, analysis, and successful results from a custom differential power analysis attack on AES-128. The resulting SCA can break any 16-byte master key the sophisticated cipher uses and it\u27s direct applications towards public-key cryptosystems will become clear. Further, the architecture of a SCA resistant scalar point algorithm accompanied by an implementation of an optimized serial multiplier will be constructed. The optimized hardware design of the multiplier is highly modular and can use either NIST approved 233 & 283-bit Kobliz curves utilizing a polynomial basis. The proposed architecture will be implemented on Kintex-7 FPGA to later be integrated with the ARM Cortex-A9 processor on the Zynq-7000 AP SoC (XC7Z045) for seamless data transfer and analysis of the vulnerabilities SCAs can exploit

    Ein flexibles, heterogenes Bildverarbeitungs-Framework fĂĽr weltraumbasierte, rekonfigurierbare Datenverarbeitungsmodule

    Get PDF
    Scientific instruments as payload of current space missions are often equipped with high-resolution sensors. Thereby, especially camera-based instruments produce a vast amount of data. To obtain the desired scientific information, this data usually is processed on ground. Due to the high distance of missions within the solar system, the data rate for downlink to the ground station is strictly limited. The volume of scientific relevant data is usually less compared to the obtained raw data. Therefore, processing already has to be carried out on-board the spacecraft. An example of such an instrument is the Polarimetric and Helioseismic Imager (PHI) on-board Solar Orbiter. For acquisition, storage and processing of images, the instrument is equipped with a Data Processing Module (DPM). It makes use of heterogeneous computing based on a dedicated LEON3 processor in combination with two reconfigurable Xilinx Virtex-4 Field-Programmable Gate Arrays (FPGAs). The thesis will provide an overview of the available space-grade processing components (processors and FPGAs) which fulfill the requirements of deepspace missions. It also presents existing processing platforms which are based upon a heterogeneous system combining processors and FPGAs. This also includes the DPM of the PHI instrument, whose architecture will be introduced in detail. As core contribution of this thesis, a framework will be presented which enables high-performance image processing on such hardware-based systems while retaining software-like flexibility. This framework mainly consists of a variety of modules for hardware acceleration which are integrated seamlessly into the data flow of the on-board software. Supplementary, it makes extensive use of the dynamic in-flight reconfigurability of the used Virtex-4 FPGAs. The flexibility of the presented framework is proven by means of multiple examples from within the image processing of the PHI instrument. The framework is analyzed with respect to processing performance as well as power consumption.Wissenschaftliche Instrumente auf aktuellen Raumfahrtmissionen sind oft mit hochauflösenden Sensoren ausgestattet. Insbesondere kamerabasierte Instrumente produzieren dabei eine große Menge an Daten. Diese werden üblicherweise nach dem Empfang auf der Erde weiterverarbeitet, um daraus wissenschaftlich relevante Informationen zu gewinnen. Aufgrund der großen Entfernung von Missionen innerhalb unseres Sonnensystems ist die Datenrate zur Übertragung an die Bodenstation oft sehr begrenzt. Das Volumen der wissenschaftlich relevanten Daten ist meist deutlich kleiner als die aufgenommenen Rohdaten. Daher ist es vorteilhaft, diese bereits an Board der Sonde zu verarbeiten. Ein Beispiel für solch ein Instrument ist der Polarimetric and Helioseismic Imager (PHI) an Bord von Solar Orbiter. Um die Daten aufzunehmen, zu speichern und zu verarbeiten, ist das Instrument mit einem Data Processing Module (DPM) ausgestattet. Dieses nutzt ein heterogenes Rechnersystem aus einem dedizierten LEON3 Prozessor, zusammen mit zwei rekonfigurierbaren Xilinx Virtex-4 Field-Programmable Gate Arrays (FPGAs). Die folgende Arbeit gibt einen Überblick über verfügbare Komponenten zur Datenverarbeitung (Prozessoren und FPGAs), die den Anforderungen von Raumfahrtmissionen gerecht werden, und stellt einige existierende Plattformen vor, die auf einem heterogenen System aus Prozessor und FPGA basieren. Hierzu gehört auch das Data Processing Module des PHI Instrumentes, dessen Architektur im Verlauf dieser Arbeit beschrieben wird. Als Kernelement der Dissertation wird ein Framework vorgestellt, das sowohl eine performante, als auch eine flexible Bilddatenverarbeitung auf einem solchen System ermöglicht. Dieses Framework besteht aus verschiedenen Modulen zur Hardwarebeschleunigung und bindet diese nahtlos in den Datenfluss der On-Board Software ein. Dabei wird außerdem die Möglichkeit genutzt, die eingesetzten Virtex-4 FPGAs dynamisch zur Laufzeit zu rekonfigurieren. Die Flexibilität des vorgestellten Frameworks wird anhand mehrerer Fallbeispiele aus der Bildverarbeitung von PHI dargestellt. Das Framework wird bezüglich der Verarbeitungsgeschwindigkeit und Energieeffizienz analysiert

    Advanced cryptographic system : design, architecture and FPGA implementation

    Get PDF
    PhD ThesisThe field programmable gate array (FPGA) is a powerful technology, and since its introduction broad prospects have opened up for engineers to creatively design and implement complete systems in various fields. One such area that has a long history in information and network security is cryptography, which is considered in this thesis. The challenge for engineers is to design secure cryptographic systems, which should work efficiently on different platforms with the levels of security required. In addition, cryptographic functionalities have to be implemented with acceptable degrees of complexity while demanding lower power consumption. The present work is devoted to the design of an efficient block cipher that meets contemporary security requirements, and to implement the proposed design in a configurable hardware platform. The cipher has been designed according to Shannon’s principles and modern cryptographic theorems. It is an iterated symmetric-key block cipher based on the substitution permutation network and number theoretic transform with variable key length, block size and word length. These parameters can be undisclosed when determined by the system, making cryptanalysis almost impossible. The aim is to design a more secure, reliable and flexible system that can run as a ratified standard, with reasonable computational complexity for a sufficient service time. Analyses are carried out on the transforms concerned, which belong to the number theoretic transforms family, to evaluate their diffusion power, and the results confirm good performance in this respect mostly of a minimum of 50%. The new Mersenne number transform and Fermat number transform were included in the design because their characteristics meet the basic requirements of modern cryptographic systems. A new 7×7 substitution box (S-box) is designed and its non-linear properties are evaluated, resulting in values of 2-6 for maximum difference propagation probability and 2-2.678 for maximum input-output correlation. In addition, these parameters are calculated for all S-boxes belonging to the previous and current standard algorithms. Moreover, three extra S-boxes are derived from the new S-box and another three from the current standard, preserving the same non-linear properties by reordering the output elements. The robustness of the proposed cipher in terms of differential and linear cryptanalysis is then considered, and it is proven that the algorithm is secure against such well-known attacks from round three onwards regardless of block or key length. A number of test vectors are run to verify the correctness of the algorithm’s implementation in terms of any possible error, and all results were promising. Tests included the known answer test, the multi-block message test, and the Monte Carlo test. Finally, efficient hardware architectures for the proposed cipher have been designed and implemented using the FPGA system generator platform. The implementations are run on the target device, Xilinx Virtex 6 (XC6VLX130T-2FF484). Using parallel loop-unrolling architecture, a high throughput of 44.9 Gbits/sec is achieved with a power consumption of 1.83W and 8030 slices for implementing the encryption module with key and block lengths of 16×7 bits. There are a variety of outcomes when the cipher is implemented on different FPGA devices as well as for different block and key lengths.Ministry of Higher Education and Scientific Research in Ira

    Project and development of hardware accelerators for fast computing in multimedia processing

    Get PDF
    2017 - 2018The main aim of the present research work is to project and develop very large scale electronic integrated circuits, with particular attention to the ones devoted to image processing applications and the related topics. In particular, the candidate has mainly investigated four topics, detailed in the following. First, the candidate has developed a novel multiplier circuit capable of obtaining floating point (FP32) results, given as inputs an integer value from a fixed integer range and a set of fixed point (FI) values. The result has been accomplished exploiting a series of theorems and results on a number theory problem, known as Bachet’s problem, which allows the development of a new Distributed Arithmetic (DA) based on 3’s partitions. This kind of application results very fit for filtering applications working on an integer fixed input range, such in image processing applications, in which the pixels are coded on 8 bits per channel. In fact, in these applications the main problem is related to the high area and power consumption due to the presence of many Multiply and Accumulate (MAC) units, also compromising real-time requirements due to the complexity of FP32 operations. For these reasons, FI implementations are usually preferred, at the cost of lower accuracies. The results for the single multiplier and for a filter of dimensions 3x3 show respectively delay of 2.456 ns and 4.7 ns on FPGA platform and 2.18 ns and 4.426 ns on 90nm std_cell TSMC 90 nm implementation. Comparisons with state-of-the-art FP32 multipliers show a speed increase of up to 94.7% and an area reduction of 69.3% on FPGA platform. ... [edited by Author]XXXI cicl
    corecore