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[Keyword] rent's rule(8hit)

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  • Verification of Moore's Law Using Actual Semiconductor Production Data

    Junichi HIRASE  

     
    PAPER-Semiconductor Materials and Devices

      Vol:
    E97-C No:6
      Page(s):
    599-608

    One of the technological innovations that has enabled the VLSI semiconductor industry to reduce the transistor size, increase the number of transistors per die, and also follow Moore's law year after year is the fact that an equivalent yield and equivalent testing quality have been ensured for the same die size. This has contributed to reducing the economically optimum production cost (production cost per component) as advocated by Moore. In this paper, we will verify Moore's law using actual values from VLSI manufacturing sites while introducing some of the technical progress that occurred from 1970 to 2010.

  • A Performance/Energy Analysis and Optimization of Multi-Core Architectures with Voltage Scaling Techniques

    Jeong-Gun LEE  Wook SHIN  Suk-Jin KIM  Eun-Gu JUNG  

     
    PAPER-VLSI Design Technology and CAD

      Vol:
    E93-A No:6
      Page(s):
    1215-1225

    In this paper, we develop asymptotic analysis and simulation models to better understand the characteristics of performance and energy consumption in a multi-core processor design in which dynamic voltage scaling is used. Our asymptotic model is derived using Amdahl's law, Rent's rule and power equations to derive the optimum number of cores and their voltage levels. Our model can predict the possible impact of different multi-core processor configurations on the performance and energy consumption for given workload characteristics (e.g. available parallelism) and process technology parameters (e.g. ratios of dynamic and static energies to total energy). Through the asymptotic analysis and optimization based on the models, we can observe an asymptotic relationship between design parameters such as "the number of cores," "core size" and "voltage scaling strategies" of a multi-core architecture with regards to performance and energy consumption at an initial phase of the design.

  • Evaluation of X Architecture Using Interconnect Length Distribution

    Hidenari NAKASHIMA  Naohiro TAKAGI  Junpei INOUE  Kenichi OKADA  Kazuya MASU  

     
    PAPER-Interconnect

      Vol:
    E88-A No:12
      Page(s):
    3437-3444

    In this paper, we propose a new Interconnect Length Distribution (ILD) model to evaluate X architecture. X architecture uses 45-wire orientations in addition to 90-wire orientations, which contributes to reduce the total wire length and the number of vias. In this paper, we evaluated interconnect length distribution of diagonal (45orientations) and all-directional wiring. The average length and the longest length of interconnect are estimated, and 18% reduction in power consumption and 17% improvement in clock frequency can be obtained by the diagonal wiring in the experimental results. The all-directional wiring does not have large advantage as compared the diagonal wiring.

  • FPGAs with Multidimensional Switch Topology

    Yohei MATSUMOTO  Akira MASAKI  

     
    LETTER-VLSI Systems

      Vol:
    E88-D No:4
      Page(s):
    775-778

    This manuscript proposes an FPGA by embedding a multidimensional switch topology onto a two-dimensional chip. We show, using Rent's Rule, that this procedure reduces the number of switches. Then we propose the actual procedure and demonstrate that this does not increase metal wire density critically.

  • Investigations of Optimum Tier Architectures for ASICs

    Kan TAKEUCHI  Kazumasa YANAGISAWA  Kazuko SAKAMOTO  Teruya TANAKA  

     
    PAPER-VLSI Design Technology and CAD

      Vol:
    E87-A No:11
      Page(s):
    2983-2989

    The optimum tier architectures for ASICs are investigated by using a methodology for predicting packing efficiency of a logic block (the ratio of total cell area to the block area including space regions between cells). In the methodology based on Rent's rule, (1) the empirical parameters required for the prediction are derived from the results of our ASIC products. (2) The concept of logic distance, which is expressed in units of the number of cells rather than the absolute net length, is introduced. (3) Not only performance constraints but also reliability constraints are incorporated. These allow us to make a quantitative comparison of the packing efficiency between various cell and tier structures. It is found that, for mega-cell blocks, all minimum-pitch layer architecture with buffer insertion is expected to give more than 20% reduction in block areas compared to the minimum-pitch + bi-pitch architecture, while satisfying the performance and reliability constraints.

  • A New FPGA Architecture for High Performance Bit-Serial Pipeline Datapath

    Akihisa OHTA  Tsuyoshi ISSHIKI  Hiroaki KUNIEDA  

     
    PAPER-VLSI Design Technology and CAD

      Vol:
    E83-A No:8
      Page(s):
    1663-1672

    In this paper, we present our work on the design of a new FPGA architecture targeted for high-performance bit-serial pipeline datapath. Bit-parallel systems require large amount of routing resource which is especially critical in using FPGAs. Their device utilization and operation frequency become low because of large routing penalty. Whereas bit-serial circuits are very efficient in routing, therefore are able to achieve a very high logic utilization. Our proposed FPGA architecture is designed taking into account the structure of bit-serial circuits to optimize the logic and routing architecture. Our FPGA guarantees near 100% logic utilization with a straightforward place and route tool due to high routability of bit-serial circuits and simple routing interconnect architecture. The FPGA chip core which we designed consists of around 200k transistors on 3.5 mm square substrate using 0.5 µm 2-metal CMOS process technology.

  • Routability Analysis of Bit-Serial Pipeline Datapaths

    Tsuyoshi ISSHIKI  Wayne Wei-Ming DAI  Hiroaki KUNIEDA  

     
    PAPER

      Vol:
    E80-A No:10
      Page(s):
    1861-1870

    In this paper, we will show some significant results of the routability analysis of bit-serial pipeline datapath designs based on Rent's rule and Donath's observation. Our results show that all of the tested bit-serial benchmarks have Rent exponent of below 0.4, indicating that the average wiring length of the circuit is expected to be independent of the circuit size. This study provides some important implications on the silicon utilization and time-area efficiency of bit-serial pipeline circuits on FPGAs and ASICs.

  • Estimating Interconnection Lengths in Three-Dimensional Computer Systems

    Dirk STROOBANDT  Jan VAN CAMPENHOUT  

     
    PAPER-Physical Design

      Vol:
    E80-D No:10
      Page(s):
    1024-1031

    In computer hardware there is a constant evolution towards smaller transistor sizes. At the same time, more and more transistors are placed on one chip. Both trends make the pin limitation problem worse. Scaling down chip sizes adds to the shortage of available pins while increasing the number of transistors per chip imposes a higher need for chip terminals. The use of three-dimensional systems would alleviate this pin limitation problem. In order to decide whether the benefits of such systems balance the higher processing costs, one must be able to characterize these benefits accurately. This can be done by estimating important layout properties of electronic designs, such as space requirements and interconnection length values. For a two-dimensional placement, Donath found an upper bound for the average interconnection length that follows the trends of experimentally obtained average lengths. Yet, this upper bound deviates from the experimentally obtained value by a factor of approximately 2 which is not sufficiently accurate for some applications. In this paper, we first extend Donath's technique to a three-dimensional placement. We then compute a significantly more accurate estimate by taking into account the inherent features of the optimal placement process.