嵌入式开发基本流程(英文版精华).pdfVIP

Developing embedded applications Before you start developing your embedded application software, you should read about these concepts: ● The development cycle ● Commonly used software models ● The build process ● Programming for performance ● Considering hardware and software factors ● Application execution. THE DEVELOPMENT CYCLE Before the actual development starts you must gather requirements and design and specify your application architecture (manually or using automated code generation tools, such as visualSTATE). Then, you are ready to start the IAR Embedded Workbench IDE. This is a typical development cycle: ● Set up a project, which includes general and tool-specific options ● Create your source code files in C, C++, or assembler ● Build—compile and link—your project for debugging ● Correct any errors in your source code ● Test and debug your application ● Build for release ● Load the image to flash or PROM memory. Developing embedded applications 21 COMMONLY USED SOFTWARE MODELS These are some commonly used software models: ● Superloop systems (tasks are performed in sequence) ● Multitask systems (tasks are scheduled by an RTOS) ● State machine models. Typically, you have either a superloop system or a multitask system, and a popular way of organizing the logic of your application is to design it using state machines. Superloop systems Without a multitasking kernel, only one task can be executed by the CPU at a time. This is called a single-task system or a superloop; basically a program that runs in an endless loop and executes the appropriate operations in sequence. No real-time kernel is used, so interrupt service routines (ISRs) must be used for real-time