High performance VLSI CORDIC algorithms,architecture and chip design

Abstract

CORDIC is a rotation based computation kernel algorithm which has been found to be very attractive for problems which require intensive, frequent evaluations of elementary functions. This paper addresses the implementation issues in the design of a VLSI CORDIC processor for digital signal processing and numerical linear algebra computations. The first part of this paper will discuss various design considerations for practical CORDIC algorithms. In particular, we have established criteria for the selection of nearly optimal shift sequences which are crucial to the performance of the CORDIC computation. The various design considerations of a CORDIC processor are discussed. Finally, the architecture of a prototype CORDIC processor data path chip is described.     

The potential for mechanical design compilation

Significant potential exists for engineering design research to produce viable approaches to automatic compilation of mechanical systems.     

数字视频后处理IP模块的VLSI设计

在讨论数字视频后处理增强算法的基础上，提出了一种数字视频信号后处理IP模块的VLSI实现方法。针对视频信号处理实时性以及运算量大的特点，提出了基于同步并行流水线的VLSI结构。应用0．35μm CMOS工艺对该IP模块设计进行了综合验证，并成功地将其应用于数字化处理电视的视频格式转换专用芯片VPP860的设计中。     

An application of an expert system in layout compaction of VLSI design

Abstract

Recent research in knowledge‐based expert systems of VLSI design tools has concentrated on placement, routing, and cell generation. This paper presents an alternative application for artificial intelligence (AI) techniques on compaction design for a VLSI mask layout‐expert compactor. In order to overcome the shortcomings of iterative search through a large problem space within a working memory, and therefore, to speed‐up the runtime of compaction, a set of rule‐based region query operations and knowledge‐based techniques for the plane sweep method are proposed in this system. Experimental results have explored the possibility of using expert system technology (EST) to automate the compaction process by “reasoning” out the layout design and applying sophisticated expert rules to its knowledge base.     

Modeling leakage power reduction in VLSI as optimization problems

Reducing power dissipation is one of the most important issues in VLSI design today. Scaling causes subthreshold leakage currents to become a large component of total power dissipation. Multi-Threshold CMOS (MTCMOS) technology has emerged as a promising technique to reduce leakage power. This paper first introduces how to model the sleep transistor sizing problem in the MTCMOS circuits as a Bin-Packing Problem (BPP). The gate-clustering BPP and the First-Fit (FF) techniques are also introduced to further improve the solution quality. To take the circuit’s routing complexity into consideration which is critical for Deep Sub-Micron (technologies that are 0.25 μm and below) (DSM) implementations, a Set-Partitioning Problem (SPP) is then formed. However, this highly constrained model limits it’s application for large circuit design. A Set-Covering (SCP) model is therefore investigated to efficiently solve the problem.     

VLSI floorplan repair using dynamic white-space management,constraint graphs,and linear programming

In VLSI layout, floorplanning refers to the task of placing macrocells on a chip without overlap while minimizing design objectives such as timing, congestion, and wire length. Experienced VLSI designers have traditionally been able to produce more efficient floorplans than automated methods. However, with the increasing complexity of modern circuits, manual design flows have become infeasible. An efficient top-down strategy for overlap removal which repairs overlaps in floorplans produced by placement algorithms or rough floorplanning methodologies is presented in this article. The algorithmic framework proposed incorporates a novel geometric shifting technique coupled with topological constraint graphs and linear programming within a top-down flow. The effectiveness of this framework is quantified across a broad range of floorplans produced by multiple tools. The method succeeds in producing valid placements in almost all cases; moreover, compared with leading methods, it requires only one-fifth of the run-time and produces placements with 4–13% less wire length and up to 43% less cell movement.     

A meta-model for mechanical products based upon the mechanical design process

This paper describes preliminary work toward the develoment of a framework and a system for modeling the meta-physical information of mechanical products. Meta-physical information is that information which describes the nature or reason for existence of objects in the physical product model. Such information includes product and feature functionality, design intent, relations, constraints and viewpoint-dependent definitions. This effort has resulted in an initial model structure and a prototype system. The product model consists of a meta-physical product model with attached physical product models containing, among other information, geometry, dimensions, tolerances, and features. The content and structure of the product model correspond directly to the information used and produced during the mechanical design process. The prototype system integrates a solid modeler, a feature modeler, a dimension and tolerance modeler, and a meta-physical modeler. This paper provides an overview of the meta-model structure, usage and potential.     

Packaging reduction by design

German legislation on the avoidance of packaging waste has provoked German industry to reduce packaging in a number of ways. One of these is reducing the sensitivity of engineered products to transport conditions. The principle of designing such products for the minimisation of their packaging requirements should be supplemented to existing design principles and should be included within the conventional design process. Thereby, future savings of materials, energy and recycling would be ensured and the competitiveness of industry would be increased as a result of cost reductions.     

Complex system design technique

The development of concepts for new generations of products that are located at the convergence of various cutting-edge technologies requires: integration of knowledge from different fields of science and technology; the management of non-linear interactions of technical, cognitive and organizational nature; the handling of multiple and inconsistent information; innovative solving of negative correlations between different system's characteristics, etc. Despite specialists’ experience, empirical approaches to the synthesis process for this category of products do not represent a reliable solution. An innovative tool for the systematic management of the synthesis process of complex innovative products is introduced in this paper. It is called the complex system design technique (CSDT) and incorporates a set of coefficients and a specific algorithm that take data from product performance planning process (e.g. data extracted from QFD-type matrices) for the formulation of a working scheme for system design (WSSD). This scheme represents a practical tool for the new product synthesis (design) process. It also allows systematic integration of innovation and analysis tools (e.g. TRIZ, AFD, Pugh, Design-FMEA, etc.) in the product synthesis process.     

Function sharing in mechanical design

Function sharing is the simultaneous implementation of several functions by a single structural element. This article describes how the idea of function sharing can be used in a computational design procedure that produces efficient designs from modular designs. These ideas have been implemented as a computer program for the domain of mechanical devices that can be described functionally as a network of lumped-parameter idealized elements.     

Load—strength simulation of a mechanical design

The load—strength theory is used to simulate the movements of a mechanical mechanism consisting of a lever and a spring. The purpose of the mechanism is automatically to select the correct speed for a turntable depending on the size (weight) of the record. The procedure for the computation is given in detail.     

A knowledge-based system for materials selection in mechanical engineering design

This paper studies various work on the development of computerized material selection system. The importance of knowledge-based system (KBS) in the context of concurrent engineering is explained. The study of KBS in material selection in an engineering design process is described. The development in materials databases, which sometimes serve as material selection packages, is also discussed. The use of KBS in material selection and the application in the domain of polymeric-based composite are chosen as typical examples.     

Tolerance analysis and design of nesting forces for exactly constrained mechanical assemblies

In this research we investigate the analysis and design of nesting forces for exactly constrained mechanical assemblies. Exactly constrained assemblies have a number of important advantages over other assemblies including the ability to assemble over a wide range of conditions. Such designs often require nesting forces to keep the design properly seated. To date, little theory has been developed for the analysis and design of nesting forces. We show how the effects of tolerances on nesting forces, a key issue, can be analyzed and then apply the analysis to two example problems. Good agreement is obtained between the method and Monte Carlo simulation.     

A hierarchical classification scheme to define and order the design space for integral snap-fit assembly

The diversity of integral attachment snap-fit feature types (e.g. cantilever hooks, bayonet-fingers, compressive hooks, annular snaps, and others), and their possible combinations, sizes and locations and orientations on parts to enable assembly has made it appear that design possibilities may be unbounded. Attempts at understanding, no less optimization, seemed intractable. This paper presents a hierarchical classification scheme that brings order to the design space, and uses that classification scheme to define boundaries and size of the design space for achieving attachment at a level above feature detailing. Classification is based on the essential geometry of parts being assembled. The result is surprising order and simplicity, and the ability to reduce viable options for any assembly situation to a number (e.g. 8–10) that will permit true optimization.     

Mechanical reliability by design

With distributed loads and strengths the condition of minimum whole life cost defines uniquely the safety margin (or factor of safety) that must be used. Established empirical factors used in current deterministic design are not then relevant. It is postulated that computer-aided design packages should incorporate a simultaneous optimization of the safety margin and maintenance policy in place of these factors, since once the design is finalized the whole life cost is finalized. The full development of stochastic CAD methods is seen as the next essential step to advance design techniques.     

Promoting risk communication in early design through linguistic analyses

The concept of function offers significant potential for transforming thinking and reasoning about engineering design as well as providing a common thread for relating together product risk information. This paper focuses specifically on risk data by examining how this information is addressed for a design team conducting early stage design for space missions. A fundamental set of risk elements is proposed based on a linguistic analysis of the risk information needs of the design team. Sample risk statements are then decomposed into a set of key attributes that are used to scrutinize the risk information using three approaches from the pragmatics sub-field of linguistics: (1) Gricean, (2) Relevance Theory, and (3) Functional Analysis. Based on the deficiencies identified in this analysis, a format for the communication of risk data by explicitly accounting for five risk attributes developed in this work is formulated.     

A new approach to the positive mean stress diagram in mechanical design

The Gerber, modified Goodman, Soderberg, Bagci, ASME‐elliptic and Clemson diagrams are proposed for estimating mechanical element fatigue strength under positive mean and alternating stresses. However, all of these diagrams are either conservative or have fields containing stress greater than yield strength of mechanical element materials. The aim of this study was to propose a new simple diagram with an exponential power k for various types of mechanical element materials. Exponential power k values of steel and Al‐alloy materials were about 0.80 and 0.45, respectively. The proposed diagram (Sekercioglu line) had a minimum average absolute deviation (X_m) of 8.56 %, lower than the Bagci, ASME‐elliptic and Clemson diagrams. The Sekercioglu line can be successfully used in fatigue design processes because of its simple structure and its less conservative nature.     

Mathematical model for warehouse design and product allocation

The two primary functions of a warehouse include (1) temporary storage and protection of goods and (2) providing value added services such as fulfilment of individual customer orders, packaging of goods, after sales services, repairs, testing, inspection and assembly. To perform the above functions, the warehouse is divided into several functional areas such as reserve storage area, forward (order collation) area and cross-docking. The paper presents a mathematical model and a heuristic algorithm that jointly determine product allocation to the functional areas in the warehouse as well as the size of each area using data readily available to a warehouse manager.     

The design of mechanical equipment for the limitation of in-service failure

Mechanical equipment design demands a deep understanding of the inherent failure mechanisms likely to be encountered in service operation. Such understanding can result in the eradication or the limitation of the effects of in-service failures. This aspect of engineering design is examined and a case study example, in which the design of stand-by equipment involved the limitation of fretting corrosion, is used as an illustration of the general principles involved.