What is Absolute Address?

Absolute address is a term commonly used in computer science and programming. It refers to the specific location of a memory cell or storage unit in a computer’s memory. In other words, it is the unique numerical value assigned to a memory location in a computer system’s memory hierarchy. Absolute address is also known as a memory address or a physical address.

When a program is executed, the computer’s CPU retrieves instructions and data from memory. To access a particular instruction or data, the CPU needs to know its memory address. Absolute addressing provides a way for the CPU to locate and access memory locations in a computer’s memory hierarchy.

Each memory location in a computer system has a unique absolute address. The absolute address is a binary number that represents the location of the memory cell in the computer’s memory hierarchy. The absolute address is typically represented in hexadecimal notation, which is easier for humans to read and understand.

When a program is compiled, the compiler assigns absolute addresses to every instruction and data element in the program. The absolute address is determined by the size and organization of the computer’s memory hierarchy. This means that the absolute address of a memory location may be different on different computers or even on the same computer if the memory hierarchy is changed.

There are two types of absolute addressing: direct and indirect. Direct addressing is used when the memory location is specified directly in the instruction. Indirect addressing is used when the memory location is specified indirectly through a pointer or an index.

One advantage of absolute addressing is that it provides a fast and efficient way for the CPU to access memory locations. The CPU can quickly retrieve data and instructions from memory by using the absolute address. However, absolute addressing has some disadvantages as well. One major disadvantage is that it makes it difficult to relocate programs in memory. If a program is moved to a different location in memory, all of its absolute addresses must be updated.

In conclusion, absolute addressing is a fundamental concept in computer science and programming. It provides a way for the CPU to locate and access memory locations in a computer’s memory hierarchy. Absolute addressing is essential for the efficient operation of computer systems, but it also has some limitations that must be considered by programmers and system designers.