Cost modelling and concurrent engineering for testable design

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.As integrated circuits and printed circuit boards increase in complexity, testing becomes a major cost factor of the design and production of the complex devices. Testability has to be considered during the design of complex electronic systems, and automatic test systems have to be used in order to facilitate the test. This fact is now widely accepted in industry. Both design for testability and the usage of automatic test systems aim at reducing the cost of production testing or, sometimes, making it possible at all. Many design for testability methods and test systems are available which can be configured into a production test strategy, in order to achieve high quality of the final product. The designer has to select from the various options for creating a test strategy, by maximising the quality and minimising the total cost for the electronic system. This thesis presents a methodology for test strategy generation which is based on consideration of the economics during the life cycle of the electronic system. This methodology is a concurrent engineering approach which takes into account all effects of a test strategy on the electronic system during its life cycle by evaluating its related cost. This objective methodology is used in an original test strategy planning advisory system, which allows for test strategy planning for VLSI circuits as well as for digital electronic systems. The cost models which are used for evaluating the economics of test strategies are described in detail and the test strategy planning system is presented. A methodology for making decisions which are based on estimated costing data is presented. Results of using the cost models and the test strategy planning system for evaluating the economics of test strategies for selected industrial designs are presented

The Fifth NASA Symposium on VLSI Design

The fifth annual NASA Symposium on VLSI Design had 13 sessions including Radiation Effects, Architectures, Mixed Signal, Design Techniques, Fault Testing, Synthesis, Signal Processing, and other Featured Presentations. The symposium provides insights into developments in VLSI and digital systems which can be used to increase data systems performance. The presentations share insights into next generation advances that will serve as a basis for future VLSI design

A Modular Approach to Adaptive Reactive Streaming Systems

The latest generations of FPGA devices offer large resource counts that provide the headroom to implement large-scale and complex systems. However, there are increasing challenges for the designer, not just because of pure size and complexity, but also in harnessing effectively the flexibility and programmability of the FPGA. A central issue is the need to integrate modules from diverse sources to promote modular design and reuse. Further, the capability to perform dynamic partial reconfiguration (DPR) of FPGA devices means that implemented systems can be made reconfigurable, allowing components to be changed during operation. However, use of DPR typically requires low-level planning of the system implementation, adding to the design challenge. This dissertation presents ReShape: a high-level approach for designing systems by interconnecting modules, which gives a ‘plug and play’ look and feel to the designer, is supported by tools that carry out implementation and verification functions, and is carried through to support system reconfiguration during operation. The emphasis is on the inter-module connections and abstracting the communication patterns that are typical between modules – for example, the streaming of data that is common in many FPGA-based systems, or the reading and writing of data to and from memory modules. ShapeUp is also presented as the static precursor to ReShape. In both, the details of wiring and signaling are hidden from view, via metadata associated with individual modules. ReShape allows system reconfiguration at the module level, by supporting type checking of replacement modules and by managing the overall system implementation, via metadata associated with its FPGA floorplan. The methodology and tools have been implemented in a prototype for a broad domain-specific setting – networking systems – and have been validated on real telecommunications design projects

Algorithm to layout (ATL) systems for VLSI design

PhD ThesisThe complexities involved in custom VLSI design together with the failure of CAD techniques to keep pace with advances in the fabrication technology have resulted in a design bottleneck. Powerful tools are required to exploit the processing potential offered by the densities now available. Describing a system in a high level algorithmic notation makes writing, understanding, modification, and verification of a design description easier. It also removes some of the emphasis on the physical issues of VLSI design, and focus attention on formulating a correct and well structured design. This thesis examines how current trends in CAD techniques might influence the evolution of advanced Algorithm To Layout (ATL) systems. The envisaged features of an example system are specified. Particular attention is given to the implementation of one its features COPTS (Compilation Of Occam Programs To Schematics). COPTS is capable of generating schematic diagrams from which an actual layout can be derived. It takes a description written in a subset of Occam and generates a high level schematic diagram depicting its realisation as a VLSI system. This diagram provides the designer with feedback on the relative placement and interconnection of the operators used in the source code. It also gives a visual representation of the parallelism defined in the Occam description. Such diagrams are a valuable aid in documenting the implementation of a design. Occam has also been selected as the input to the design system that COPTS is a feature of. The choice of Occam was made on the assumption that the most appropriate algorithmic notation for such a design system will be a suitable high level programming language. This is in contrast to current automated VLSI design systems, which typically use a hardware des~ription language for input. These special purpose languages currently concentrate on handling structural/behavioural information and have limited ability to express algorithms. Using a language such as Occam allows a designer to write a behavioural description which can be compiled and executed as a simulator, or prototype, of the system. The programmability introduced into the design process enables designers to concentrate on a design's underlying algorithm. The choice of this algorithm is the most crucial decision since it determines the performance and area of the silicon implementation. The thesis is divided into four sections, each of several chapters. The first section considers VLSI design complexity, compares the expert systems and silicon compilation approaches to tackling it, and examines its parallels with software complexity. The second section reviews the advantages of using a conventional programming language for VLSI system descriptions. A number of alternative high level programming languages are considered for application in VLSI design. The third section defines the overall ATL system COPTS is envisaged to be part of, and considers the schematic representation of Occam programs. The final section presents a summary of the overall project and suggestions for future work on realising the full ATL system