What is Assembly Language Programming?:

To overcome the limitations of machine languages, assembly language was developed. In this language, machine-level instructions are replaced by mnemonics. For example, ADD represents addition, SUB rep­resents subtraction, INC for increment, RAL for rotate left, and CMP for compare. These instructions are known as mnemonics. A program written in mnemonics is called an assembly language Programming. It is easier for a programmer to write programs in assembly language compared to those in machine language. It is also easier to understand an assembly-language program. Such programs are microprocessor-specific.

Assembly-language Program are translated to machine-level programs using a translator program known as assembler, as shown in Fig. 4.1.

Advantages of Assembly Language:

1. It is easy to write.
2. It is easy to understand.
3. Assembly-language programs produce faster results.
4. It is suitable for real-time control and industrial applications.
5. It requires less computation time.

Disadvantages of assembly language compared to high-level languages are given below:

1. An assembly language is microprocessor specific. Detailed knowledge of the particular microproces­sor is required to write a program. The programmer should know all about registers and instructions of the microprocessor.
2. An assembly language program is not portable, as a program written for one microprocessor may not be used in other processors.
3. Assembly-language program writing is difficult and time consuming compared to that of high-level languages.