ch开发工具方法及流程分析.ppt

? 2009 Design and Application Of Embedded System * Challenges, etc. Does it really work? Is the specification correct? Does the implementation meet the spec? How do we test for real-time characteristics? How do we test on real data? How do we work on the system? Observability, controllability? What is our development platform? ? 2009 Design and Application Of Embedded System * Design methodologies A procedure for designing a system. Understanding your methodology helps you ensure you didn’t skip anything. Compilers, software engineering tools, computer-aided design (CAD) tools, etc., can be used to: help automate methodology steps; keep track of the methodology itself. ? 2009 Design and Application Of Embedded System * Design goals Performance. Overall speed, deadlines. Functionality and user interface. Manufacturing cost. Power consumption. Other requirements (physical size, etc.) ? 2009 Design and Application Of Embedded System * Levels of abstraction requirements specification architecture component design system integration Top-down Bottom-up ? 2009 Design and Application Of Embedded System * Top-down vs. bottom-up Top-down design: start from most abstract description; work to most detailed. Bottom-up design: work from small components to big system. Real design uses both techniques. ? 2009 Design and Application Of Embedded System * Stepwise refinement At each level of abstraction, we must: analyze the design to determine characteristics of the current state of the design; refine the design to add detail; ensure all design objects. ? 2009 Design and Application Of Embedded System * Requirements Plain language description of what the user wants and expects to get. May be developed in several ways: talking directly to customers; talking to marketing representatives; providing prototypes to users for comment. ? 2009 Design and Application Of Embedded System * Functional vs. non-functional requirements Functional requirements: output as a function of in