Constructing hardware-software systems from a single description

Current embedded systems are made of multiple heterogeneous devices interconnected. These devices present a great variation of functionality, performance, and interfaces. Therefore, it is difficult to build applications for these platforms.

Proceedings of the conference on Design, automation and test in Europe, 2000

In this poster, we present a new specification technique for complex hardware-software systems, based on standard high-level programming languages, such as C, C++, Java, Scheme, or Ada, without extensions or semantic changes. Unlike previous approaches, the designer may choose the model of computation and the specification language that best suits her needs, while still being able to formally verify the correctness of the specification. The details of the available hardware and software resources, and the implementation of the different models of computation are encapsulated in libraries to maximize reuse in system specifications.

1994

Abstract Designers generally implement embedded controllers for reactive real-time applications as mixed software-hardware systems. In our formal methodology for specifying, modeling, automatically synthesizing, and verifying such systems, design takes place within a unified framework that prejudices neither hardware nor software implementation. After interactive partitioning, this approach automatically synthesizes the entire design, including hardware-software interfaces.

Design Automation for Embedded Systems, 2002

We describe a compositional framework, together with its supporting toolset, for hardware/software co-design. Our framework is an integration of a formal approach within a traditional design flow. The formal approach is based on Interval Temporal Logic and its executable subset, Tempura. Refinement is the key element in our framework because it will derivefrom a single formal specification of the system the software and hardware parts of the implementation, while preserving all properties of the system specification. During ...

This book introduces embedded system design using a modern approach. Modern design requires a designer to have a unified view of software and hardware, seeing them not as completely different domains, but rather as two implementation options along a continuum of options varying in their design metrics (cost, performance, power, flexibility, etc.).

1994

We present a software oriented approach to hardware/software codesign by applying traditional compiler techniques to the hardware/software partitioning problem and linking a compiler to a state of the art hardware synthesis technology. The system is specified in C or C++. Time critical regions are identified by means of profiling and are automatically implemented in user programmable logic with high level and logic synthesis design tools. The underlying architecture is an add-on board with user programmable logic, connected to a Sparc based workstation via the system bus. We present a novel partitioning technique based on a hierarchical candidate preselection scheme, that utilizes profilers and estimators for performance and cost. Our approach allows (a) efficient collection of profiling data due to the usage of C and C++ as specification languages, (b) fast partitioning due to a candidate preselection scheme, and (c) high complexity of the hardware partition due to a logic emulation system.

The design and analysis of embedded, mixed hardware/software systems, such as PC cards, application specific hardware, m-and e-commerce devices, mobile telecommunication infrastructure and associated software drivers, is hard. An important issue for correct codesign is the search for a highly compositional and unifying formal approach that crosses the hardware/software boundaries and enables us to keep up with the fast growth in the complexity and variety of electronic devices and their associated software. Hardware/software codesign is a relatively new discipline interconnecting several other fields of research such as Electronics Engineering and Computer Science with the earliest reference to codesign dated back to 1992. In this thesis, I describe an integrated compositional framework for codesign of mixed hardware/software systems, together with its underpinning theory of semantics and refinement. My work integrates formal methods into the design process and the focus of the thesis i ABSTRACT ii is on refinement from a formal specification into a formal hardware part and a formal software part. Central to my methodology is that the synthesis and design start with a single highlevel abstract specification which captures the desired behaviour(s) of the system. Decisions are then taken through correctness preserving refinement steps. I have given formal semantics to Verilog-a Hardware Description Language (HDL) conceived in and extensively used by the hardware industry-in both denotational (in specification-oriented style) and operational terms and my work on Verilog enables me to blend existing and commercially available hardware synthesis tools and methodologies into my formal framework. This has the benefit of linking software development with hardware development in an integrated fashion and therefore span the gap between hardware and software formally. The equivalence between the two forms of semantics is proven and a set of generic refinement laws is presented. A detailed case-study of a smart card application of the Rivest Shamir Adleman (RSA) encryption algorithm is provided to evaluate my approach.

2000

In the hardware industry, simulation is still all too frequently considered synonymous with verification. The design process usually consists of developing an implementation from a specification without the use of any formal proof techniques. Both are then simulated for a number of inputs (an approach known as co-simulation [1]). Bugs discovered are removed and the simulation process is repeated over again. However, formal verification cannot completely replace the existing simulation approach.

Proceedings of SYNCHRON, 2004

Virtually every system designed today is an amalgam of hardware and software. Unfortunately, software and circuits that communicate across the hardware/software boundary are tedious and error-prone to create. This suggests a more automatic way to synthesize them. This paper presents the shim language, which combines imperative C-like semantics for software and rtl-like semantics for hardware to allow a unified description of hardware/software systems. Hardware processes and software functions communicate through shared variables, hardware for which is automatically synthesized by the shim compiler, which generates C and synthesizable vhdl.

2005

I propose a systematic review and evaluation of the use of general purpose, high-level programming languages for the design and synthesis of circuit specifications that implement algorithms directly as specialized hardware configurations. Specifically, I propose an examination of the, so-called, semantic gap between the understood features and semantics of popular software programming languages such as C and C++, and the capabilities of programmable logic devices such as FPGAs. A significant amount of research effort has already been devoted to this topic, but it is my belief that this research has generally failed to adequately address certain key issues in both principle and implementation. My research will comprise a study of the theory and practice of programming hardware descriptions, with the aim of providing insights that suggest how to bridge the semantic gap and yield more effective hardware programming techniques.