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IV. Writing exercises:

Exercise 1

Damaged 2.Formulas.3.Random timing. 4.Random delays. 5.Embedded system.

Exercise 2

A number of separate "chunks" of software .

The presence of the RTOS kernel.

Them run in a very timely and responsive fashion.

Lesson 10

II.Reading exercises:

Exercise 2

1. Systems programming (or system programming) is the activity of programming system software.

2. The primary distinguishing characteristic of systems programming when compared to application programming is that application programming aims to produce software which provides services to the user (e.g. word processor), whereas systems programming aims to produce software which provides services to the computer hardware (e.g. disk defragmenter). It also requires a greater degree of hardware awareness.

3. A software system consists of executable computer code and the supporting documents needed to manufacture, use, and maintain the code.

4. Requirements definition phase, design phase, coding phase, testing phase, maintenance phase.

Exercise 3

1c, 2a, 3d, 4b.

Exercise 4

1.Modularity. 2. Modules. 3.High-level languages. 4.Executable computer code.

III.Speaking exercises:

Exercise 1

Requirements phase

The purpose of the requirements phase is to define what a system should do and the constraints under which it must operate. This information is recorded in a requirements document. A typical requirements document might include a product overview; a specification of the development, operating, and maintenance environment for the product; a high-level conceptual model of the system; a specification of the user interface; specification of functional requirements; specification of nonfunctional requirements; specification of interfaces to systems outside the system under development; specification of how errors will be handled; and a listing of possible changes and enhancements to the system. Each requirement, usually numbered for reference, must be testable.

Compiler

Program that converts a source program (written in high-level language)into an object.

Coding phase

The coding phase of the software life-cycle is concerned with the development of code that will implement the design. This code is written is a formal language called a programming language. Programming languages have evolved over time from sequences of ones and zeros directly interpretable by a computer, through symbolic machine code, assembly languages, and finally to higher-level languages that are more understandable to humans.

Programming tools

A programmer typically writes the code using a text editor. Sometimes a syntax-directed editor that “knows” about a given programming language and can provide programming templates and check code for syntax errors is used. Various other tools may be used by a programmer, including a debugger that helps find errors in the code, a profiler that shows which parts of a module spend most time executing, and optimizers that make the code run faster.

Exercise 2

1.What does a software system consists of?

2.How can the higher-level languages be categorized?

3.What languages is most coding done in?

4.What is the best-known life-cycle model?.