Книга: Introduction to Microprocessors and Microcontrollers

Summary of assembly language

Assembly and machine code are not portable. This means that they are designed to be used on a particular microprocessor and are generally not able to be used on another type. They also require the programmer to have knowledge of the internal layout or architecture of the microprocessor.

Despite the two problems of portability and architecture knowledge, assembly language has survived the onslaught of the new, modern ‘improved’ languages considered in the next chapter.

Why?

Assembly languages have two overriding advantages in the hands of a competent programmer (note the ‘competent’). A program written in Assembly is faster and is more compact, i.e. it takes less memory space to store it. Machine code and assembly languages are called procedural languages. This means that the program instructs the microprocessor to complete the first instruction, then start the next, then the next and so on until it has finished the job. This is just like a recipe.

Nearly all microprocessor-based systems are designed to operate in this way and it seems so obvious that it is difficult to think that there is any alternative – but there is, as we will see later.

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