Showing papers on "Very-large-scale integration published in 2003"

Networks on chip

Abstract: We are witnessing a growing interest in Networks on Chips (NoC) that is related to the evolution of integrated circuit technology and to the growing requirements in performance and portability of electronic systems. Current integrated circuits contain several processing cores, and even relatively simple systems, such as cellular telephones, behave as multiprocessors. Moreover, many electronic systems consist of heterogeneous components and they require efficient on-chip communication. In the last few years, multiprocessing platforms have been developed to address high performance computation, such as image rendering. Examples are Sony’s emotion engine [OKA] and IBM’s cell chip [PHAM] where on-chip communication efficiency is key to the overall system performance.

Trends and challenges in VLSI circuit reliability

Abstract: Deep-submicron technology is having a significant impact on permanent, intermittent, and transient classes of faults. This article discusses the main trends and challenges in circuit reliability, and explains evolving techniques for dealing with them.

Array-based architecture for FET-based, nanoscale electronics

Abstract: Advances in our basic scientific understanding at the molecular and atomic level place us on the verge of engineering designer structures with key features at the single nanometer scale. This offers us the opportunity to design computing systems at what may be the ultimate limits on device size. At this scale, we are faced with new challenges and a new cost structure which motivates different computing architectures than we found efficient and appropriate in conventional very large scale integration (VLSI). We sketch a basic architecture for nanoscale electronics based on carbon nanotubes, silicon nanowires, and nano-scale FETs. This architecture can provide universal logic functionality with all logic and signal restoration operating at the nanoscale. The key properties of this architecture are its minimalism, defect tolerance, and compatibility with emerging bottom-up nanoscale fabrication techniques. The architecture further supports micro-to-nanoscale interfacing for communication with conventional integrated circuits and bootstrap loading.

VLSI implementations of threshold logic-a comprehensive survey

Abstract: This paper is an in-depth review on silicon implementations of threshold logic gates that covers several decades. In this paper, we will mention early MOS threshold logic solutions and detail numerous very-large-scale integration (VLSI) implementations including capacitive (switched capacitor and floating gate with their variations), conductance/current (pseudo-nMOS and output-wired-inverters, including a plethora of solutions evolved from them), as well as many differential solutions. At the end, we will briefly mention other implementations, e.g., based on negative resistance devices and on single electron technologies.

Design and performance testing of a 2.29-GB/s Rijndael processor

Abstract: This contribution describes the design and performance testing of an Advanced Encryption Standard (AES) compliant encryption chip that delivers 2.29 GB/s of encryption throughput at 56 mW of power consumption in a 0.18-/spl mu/m CMOS standard cell technology. This integrated circuit implements the Rijndael encryption algorithm, at any combination of block lengths (128, 192, or 25 bits) and key lengths (128, 192, or 256 bits). We present the chip architecture and discuss the design optimizations. We also present measurement results that were obtained from a set of 14 test samples of this chip.

Design of a switch for network on chip applications

Abstract: System on Chip (SoC) design in the forthcoming billion transistor era will involve the integration of numerous heterogeneous semiconductor intellectual property (IP) blocks Some of the main problems in the ultra deep sub micron technologies characterized by gate lengths in the range of 50-100 nm arise from non-scalable global wire delays, failure to achieve global synchronization, errors due to signal integrity issues, and difficulties associated with non-scalable bus-based functional interconnect These problems are addressed in this paper by introducing a new design methodology A switch-based network-centric architecture to interconnect IP blocks is proposed We introduce a butterfly fat tree architecture as an overall interconnect template In this new interconnect architecture, switches are used to transfer data between IP blocks To reduce overall latency and hardware overhead, wormhole routing is adopted The proposed switch architecture supports this routing method Initial implementation of the switch reveals that the total switch area is expected to amount to less than 2% of a large SoC

Built-in redundancy analysis for memory yield improvement

Abstract: With the advance of VLSI technology, the capacity and density of memories is rapidly growing. The yield improvement and testing issues have become the most critical challenges for memory manufacturing. Conventionally, redundancies are applied so that the faulty cells can be repairable. Redundancy analysis using external memory testers is becoming inefficient as the chip density continues to grow, especially for the system chip with large embedded memories. This paper presents three redundancy analysis algorithms which can be implemented on-chip. Among them, two are based on the local-bitmap idea: the local repair-most approach is efficient for a general spare architecture, and the local optimization approach has the best repair rate. The essential spare pivoting technique is proposed to reduce the control complexity. Furthermore, a simulator has been developed for evaluating the repair efficiency of different algorithms. It is also used for determining certain important parameters in redundancy design. The redundancy analysis circuit can easily be integrated with the built-in self-test circuit.

CMOS VLSI implementation of a low-power logarithmic converter

Abstract: We present a unique 32-bit binary-to-binary logarithm converter including its CMOS VLSI implementation. The converter is implemented using combinational logic only and it calculates a logarithm approximation in a single clock cycle. Unlike other complex logarithm correcting algorithms, three unique algorithms are developed and implemented with low-power and fast circuits that reduce the maximum percent errors that result from binary-to-binary logarithm conversion to 0.9299 percent, 0.4314 percent, and 0.1538 percent. Fast 4, 16, and 32-bit leading-one detector circuits are designed to obtain the leading-one position of an input binary word. A 32-word/spl times/5-bit MOS ROM is used to provide 5-bit integers based on the corresponding leading-one position. Both converter area and speed have been considered in the design approach, resulting in the use of a very efficient 32-bit logarithmic shifter in the 32-bit logarithmic converter. The converter is implemented using 0.6/spl mu/m CMOS technology, and it requires 1,600/spl lambda//spl times/2,800/spl lambda/ of chip area. Simulations of the CMOS design for the 32-bit logarithmic converter, operating at V/sub DD/ equal to 5 volts, run at 55 MHz, and the converter consumes 20 milliwatts.

Wiring requirement and three-dimensional integration technology for field programmable gate arrays

Abstract: In this paper, analytical models for predicting interconnect requirements in field-programmable gate arrays (FPGAs) are presented, and opportunities for three-dimensional (3-D) implementation of FPGAs are examined. The analytical models for two-dimensional FPGAs are calibrated by routing and placement experiments with benchmark circuits and extended to 3-D FPGAs. Based on system-level modeling, we find that in FPGAs with more than 20 K four-input look-up tables, the reduction in channel width, interconnect delay and power dissipation can be over 50% by 3-D implementation.

Perspectives on power-aware electronics

Abstract: In the coming ubiquitous-IT society, low-power design is one of the key features at which the VLSI designer should aim. Otherwise, power increase will remain as one of the main obstacles to Moore's law growth. Unless VLSI power is lowered by orders of magnitude, we cannot enjoy the progress that scaling offers. This talk will cover what we now have, and what we should provide in our low-power armory to allow us to cope with ever-increasing leakage loss, as well as dynamic power. The techniques to be presented range over the system, software, circuit, and device levels including interconnect and I/O issues. The novel trend is to examine cooperative approaches between levels such as software-circuit cooperation and circuit-technology cooperation. The biggest challenge that System-on-Chip designers must resolve in the future is the fact that transistors for digital and memory circuits will be more and more leaky as technology generations advance. Approaches to solving this serious problem will be described. Beyond the quest for low-power solutions lies a promising world of ubiquitous VLSI devices and products ranging from "wireless sensors and tags for everything" to "everything-you-must-do mobile terminals".

A low-power precomputation-based fully parallel content-addressable memory

Abstract: This paper presents a novel VLSI architecture for a fully parallel precomputation-based content-addressable memory (PB-CAM) with low-power, low-cost, and low-voltage features. This design is based on a precomputation approach that saves not only power consumption of the CAM system, but also reduces transistor count and operating voltage of the CAM cell. In addition, the proposed PB-CAM word structure adopts the static pseudo-nMOS circuit design to improve system performance. The whole design was fabricated with the TSMC 0.35-/spl mu/m single-poly quadruple-metal CMOS process. With a 128 words by 30 bits CAM size, the measurement results indicate that the proposed circuit works up to 100 MHz with power consumption of 33 mW at 3.3-V supply voltage and works up to 30 MHz under 1.5-V supply voltage.

VLSI architectures for the MAP algorithm

Abstract: This paper presents several techniques for the very large-scale integration (VLSI) implementation of the maximum a posteriori (MAP) algorithm. In general, knowledge about the implementation of the Viterbi (1967) algorithm can be applied to the MAP algorithm. Bounds are derived for the dynamic range of the state metrics which enable the designer to optimize the word length. The computational kernel of the algorithm is the add-MAX* operation, which is the add-compare-select operation of the Viterbi algorithm with an added offset. We show that the critical path of the algorithm can be reduced if the add-MAX* operation is reordered into an offset-add-compare-select operation by adjusting the location of registers. A general scheduling for the MAP algorithm is presented which gives the tradeoffs between computational complexity, latency, and memory size. Some of these architectures eliminate the need for RAM blocks with unusual form factors or can replace the RAM with registers. These architectures are suited to VLSI implementation of turbo decoders.

The Modeling, Characterization, and Design of Monolithic Inductors for Silicon RF IC's

Abstract: The results of a comprehensive investigation into the characteristics and optimization of Inductors fabricated with the top-level metal of a submicron silicon VLSI process are presented. A computer program which extncts a physics-based model of microstrip components that is suitable for circuit (SPICE) simulation has been used to evaluate the effect of variations in melallization, layout geometry, and substrate parameters upon monolithic inductor performance. Three-dimensional (3-D) numerical simulations and experimental measurements of inductors were also used to benchmark the model aecuncy. It is shown in this work that low inductor Q is primarily due to the restrictions imposed by the thin interconnect metallization available in most very large scale integration (VLSI) technolocies, and that computer optimization of the inductor layout can be used to achieve a 50% improvement in component Q-factor over unoptimized designs.

Sub-1-V CMOS proportional-to-absolute temperature references

Abstract: Presents a new all-MOS circuit technique for very-low-voltage proportional-to-absolute temperature (PTAT) references. Optimization of supply scaling below the sum of threshold voltages is based on log companding and implemented by operating the MOSFET in weak inversion. The key design equations for current (/spl mu/A) and voltage (sub-100 mV) references and their standard deviations (around 5%) are derived by analytical analysis. Two sub-1-V sub-5-/spl mu/W integrated PTAT references are presented and exhaustively tested for 1.2- and 0.35-/spl mu/m very large scale integration technologies. Both designs report good agreement between analytical, simulated, and experimental data, exhibiting PSRR(DC)+>60 dB. Hence, the resulting PTAT circuits are suitable for very-low-voltage system-on-a-chip applications in digital CMOS technologies.

Flexible and Formal Modeling of Microprocessors with Application to Retargetable Simulation

Abstract: Given the growth in application-specific processors, there is a strong need for a retargetable modeling framework that is capable of accurately capturing complex processor behaviors and generating efficient simulators. We propose the operation state machine (OSM) computation model to serve as the foundation of such a modeling framework. The OSM model separates the processor into two interacting layers: the operation layer where operation semantics and timing are modeled, and the hardware layer where disciplined hardware units interact. This declarative model allows for direct synthesis of micro-architecture simulators as it encapsulates precise concurrency semantics of microprocessors. We illustrate the practical benefits of this model through two case studies - the StrongARM core and the PowerPC-750 superscalar processor. The experimental results demonstrate that the OSM model has excellent modeling productivity and model efficiency. Additional applications of this modeling framework include derivation of information required by compilers and formal analysis for processor validation.

Power-constrained testing of VLSI circuits

Abstract: This book is the first book that covers all asopects of power-constrained test solutions. It is a reflection of authors own research and also survey of the major contributions in this domain.

Reliability-constrained area optimization of VLSI power/ground networks via sequence of linear programmings

Abstract: This paper presents a new method of sizing the widths of the power and ground routes in integrated circuits so that the chip area required by the routes is minimized subject to electromigration and IR voltage drop constraints. The basic idea is to transform the underlying constrained nonlinear programming problem into a sequence of linear programs. Theoretically, we show (that the sequence of linear programs always converges to the optimum solution of the relaxed convex optimization problem. Experimental results demonstrate that the proposed sequence-of-linear-program method Is orders of magnitude faster than the best-known method based on conjugate gradients with constantly better solution qualities.

Digital Integrated Circuits: Analysis and Design

Abstract: Exponential improvement in functionality and performance of digital integrated circuits has revolutionized the way we live and work. The continued scaling down of MOS transistors has broadened the scope of use for circuit technology to the point that texts on the topic are generally lacking after a few years. The second edition of Digital Integrated Circuits: Analysis and Design focuses on timeless principles with a modern interdisciplinary view that will serve integrated circuits engineers from all disciplines for years to come. Providing a revised instructional reference for engineers involved with Very Large Scale Integrated Circuit design and fabrication, this book delves into the dramatic advances in the field, including new applications and changes in the physics of operation made possible by relentless miniaturization. This book was conceived in the versatile spirit of the field to bridge a void that had existed between books on transistor electronics and those covering VLSI design and fabrication as a separate topic. Like the first edition, this volume is a crucial link for integrated circuit engineers and those studying the field, supplying the cross-disciplinary connections they require for guidance in more advanced work. For pedagogical reasons, the author uses SPICE level 1 computer simulation models but introduces BSIM models that are indispensable for VLSI design. This enables users to develop a strong and intuitive sense of device and circuit design by drawing direct connections between the hand analysis and the SPICE models. With four new chapters, more than 200 new illustrations, numerous worked examples, case studies, and support provided on a dynamic website, this text significantly expands concepts presented in the first edition.

VLSI implementation of a low-power antilogarithmic converter

Abstract: This paper presents a VLSI implementation of a unique 32-bit antilogarithmic converter, which generates data for some digital-signal-processing (DSP) applications. Novel antilogarithm correcting algorithms are developed and implemented with low-power and hardware-efficient correcting circuits. The VLSI implementations of these algorithms are much smaller than other hardware intensive algorithms found in the literature. The converter is implemented using 0.6 /spl mu/m CMOS technology, and its combinational logic implementation requires 1500/spl lambda//spl times/2800/spl lambda/ of chip area. The 32-bit antilogarithmic converter computes the antilogarithm in a single clock cycle and runs at 100 MHz and consumes 81 mW.

An efficient pipelined FFT architecture

Abstract: This paper presents an efficient VLSI architecture of the pipeline fast Fourier transform (FFT) processor based on radix-4 decimation-in-time algorithm with the use of digit-serial arithmetic units. By combining both the feedforward and feedback commutator schemes, the proposed architecture can not only achieve nearly 100% hardware utilization, but also require much less memory compared with the previous digit-serial FFT processors. Furthermore, in FFT processors, several modules of ROM are required for the storage of twiddle factors. By exploiting the redundancy of the factors, the overall ROM size can be effectively reduced by a factor of 2.

Three-dimensional integration: technology, use, and issues for mixed-signal applications

Abstract: Three-dimensional (3-D) integration provides opportunities in large-scale integration of mixed-signal and general system-on-chip applications with improved performance, through increased density and mixing of different active and passive technologies. This paper reports a novel low-thermal-budget 3-D fabrication technique-multilayers with buried structures (MLBS) and an analysis of its applicability to mixed-signal integration. The MLBS technique uses a low temperature of 450/spl deg/C to transfer a single-crystal silicon layer over a processed wafer consisting of buried in-plane and out-of-plane interconnects obtained through a dual Damascene process. Devices can continue to be processed on this transferred layer. Electrical characteristics of MOS capacitors (D/sub it/=4.7/spl times/10/sup 10/ cm/sup -2/ eV/sup -1/) and 3-D integrated planar CMOS transistors (3-D CMOS), fabricated using MLBS, are consistent with integration requirements. Our analog analysis includes an investigation of thermal effects important to analog applications with continuous operation of transistors in forward active bias, as well as of the coupling isolation derived from use of a ground-plane. Use of high density local interconnectivity improves the thermal properties of 3-D CMOS over that of silicon-on-insulator, and use of a ground plane is shown to lead to an improvement of better than 8 dB in coupling isolation.

Two gates are better than one [double-gate MOSFET process]

Abstract: A planar self-aligned double-gate MOSFET process has been implemented where a unique sidewall source/drain structure (S/D) permits self-aligned patterning of the back-gate layer after the S/D structure is in place. This allows coupling the silicon thickness control inherent in a planar, unpatterned layer with VLSI self-alignment techniques and also gives independently controlled front and back gates. The demanding structure led to process innovations primarily in front-end CMP, where planarity within 5 nm was achieved on an 8-in diameter wafer as well as in silicided silicon source/drain sidewalls, with minimal encroachment of the silicide. Double-gate FET (DGFET) operation is demonstrated, with good transport at both interfaces. Dense circuit layouts are achieved with multifinger devices, and logic inverters with back-gate-controlled load current as well as NOR logic using the two gates of a single transistor as inputs are demonstrated.

Thermal-ADI - a linear-time chip-level dynamic thermal-simulation algorithm based on alternating-direction-implicit (ADI) method

Abstract: Due to the dramatic increase of clock frequency and integration density, power density and on-chip temperature in high-end very large scale integration (VLSI) circuits rise significantly. To ensure the timing correctness and the reliability of high-end VLSI design, efficient and accurate chip-level transient thermal simulations are of crucial importance. In this paper, we develop and present an efficient transient thermal-simulation algorithm based on the alternating-direction-implicit (ADI) method. Our algorithm, thermal-ADI, not only has a linear run time and memory requirement , but is also unconditionally stable, which ensures that time step is not limited by any stability requirement. Extensive experimental results show that our algorithm is not only orders of magnitude faster than the traditional thermal-simulation algorithms, but also highly accurate and efficient in memory usage.

Constant-g/sub m/ constant-slew-rate high-bandwidth low-voltage rail-to-rail CMOS input stage for VLSI cell libraries

Abstract: This paper introduces a general-purpose low-voltage rail-to-rail input stage suitable for analog and mixed-signal applications. The proposed circuit provides, simultaneously, constant small-signal and large-signal behaviors over the entire input common-mode voltage range, while imposing no appreciable constraint for high-frequency operation. In addition, the accuracy of the circuit does not rely on any strict matching of the devices, unlike most of the traditional approaches based on complementary input pairs, which need to compensate for the difference in mobility between electrons and holes with the transistor aspect ratios. Also, the technique is compatible with deep submicrometer CMOS devices, where the familiar voltage-to-current square law in saturation is not completely satisfied. Based on the proposed input stage, a transconductor with rail-to-rail input common-mode range and an input/output rail-to-rail operational amplifier were developed. Both cells were designed to operate with a 3-V single supply and fabricated in standard 0.8-/spl mu/m CMOS technology. Experimental results are provided.

Fault testing for reversible circuits

Abstract: Irreversible computation necessarily results in energy dissipation due to information loss. While small in comparison to the power consumption of today's VLSI circuits, if current trends continue this will be a critical issue in the near future. Reversible circuits offer an alternative that, in principle, allows computation with arbitrarily small energy dissipation. Furthermore, reversible circuits are essential components of quantum logic. We consider the problem of testing these circuits, and in particular generating efficient test sets. The reversibility property significantly simplifies the problem, which is generally hard for the irreversible case. We discuss conditions for a test set to be complete, give a number of practical constructions, and consider test sets for worst-case circuits. In addition, we formulate the problem of finding minimal test sets into an integer linear program (ILP) with binary variables. While this ILP method is infeasible for large circuits, we show that combining it with a circuit decomposition approach yields a practical alternative.

A VLSI photonics platform

Abstract: A new high-index contrast material system, micrometer sized building blocks, and IC fabrication techniques, are leveraged in order to realize commercial VLSI photonic circuits.

Hardware implementation of the RC4 stream cipher

Abstract: In this paper, an efficient hardware implementation of the RC4 stream-cipher is proposed. In contrary to previous designs, which support only fixed length key, the proposed implementation integrates in the same hardware module an 8-bit up to 128-bit key length capability. Independently of the key length, the proposed VLSI implementation achieves a data throughput up to 22 Mbytes/sec in a maximum frequency of 64 MHz. The whole design was captured by using VHDL language and a FPGA device was used for the hardware implementation of the architecture. A detailed analysis, in terms of performance, and covered area is shown.

Energy-delay estimation technique for high-performance microprocessor VLSI adders

Abstract: We motivate the concept of comparing VLSI adders based on their energy-delay trade-offs and present a technique for estimating the energy-delay space of various high-performance VLSI adder topologies. Further, we show that our estimates accurately represent tradeoffs in the energy-delay space for high-performance 32-bit and 64-bit processor adders in 0.13/spl mu/m and 0.10/spl mu/m CMOS technologies, with an accuracy of 8% in delay estimates and 20% in energy estimates, compared with simulated data.

An automated floating-point to fixed-point conversion methodology

Abstract: We propose a floating-point to fixed-point conversion (FFC) methodology for digital VLSI signal processing systems. The past techniques used to facilitate FFC are first reviewed, followed by a description based on a statistical approach and global optimization which allows a high degree of automation.

Complementary ferroelectric-capacitor logic for low-power logic-in-memory VLSI

Abstract: A novel nonvolatile logic style, called complementary ferroelectric-capacitor (CFC) logic, is proposed for low-power logic-in-memory VLSI, in which storage elements are distributed over the logic-circuit plane. Standby currents in distributed storage elements can be cut off by using ferroelectric-based nonvolatile storage elements, and the standby power dissipation can be greatly reduced. Since the nonvolatile storage and the switching functions are merged into ferroelectric capacitors by the capacitive coupling effect, reduction of active device counts can be achieved. The use of complementary stored data in coupled ferroelectric capacitors makes it possible to perform a switching operation with small degradation of the nonvolatile charge at a low supply voltage. The restore operation can be performed by only applying the small bias across the ferroelectric capacitor, which reduces the dynamic power dissipation. Applying the proposed circuitry in a fully parallel 32-bit content-addressable memory results in about 2/3 dynamic power reduction and 1/7700 static power reduction with chip size of 1/3, compared to a CMOS implementation using 0.6-/spl mu/m ferroelectric/CMOS.