What is relocatable address and absolute address?

An address expression that has a fixed value, independent of run-time considerations such as where the program is located in memory, is called an absolute address expression. An address expression with a value that depends on run-time considerations is called a relocatable address expression.

What is the difference between symbolic addressing and absolute addressing?

An absolute address comprises an address identifier and a memory location (for example, Q 4.0, I 1.1, M 2.0, FB21). Using symbolic addresses it is easier to recognize to what extent the elements in the program match the components of your process control project.

What is a symbolic address?

An addressing scheme whereby reference to an address is made by some convenient symbol that (preferably) has some relationship to the meaning of the data expected to be located at that address. It serves as an aid to the programmer.

What is absolute address?

An absolute address is represented by the contents of a register. An absolute address is represented by the contents of a register. This addressing mode is absolute in the sense that it is not specified relative to the current instruction address.

What is protection OS?

Protection refers to a mechanism which controls the access of programs, processes, or users to the resources defined by a computer system. We can take protection as a helper to multi programming operating system, so that many users might safely share a common logical name space such as directory or files.

What is relocation and protection in OS?

Relocation : When a program is run it does not know in advance what location it will be loaded at. Protection : Once you can have two programs in memory at the same time there is a danger that one program can write to the address space of another program.

Which one is is a symbolic address for the instruction?

The symbolic address main stands for the address of the first instruction. The instruction j main tells the assembler to assemble a machine instruction with the proper 26-bit field so that control is transferred to main .

What is symbolic address in assembly language?

symbolic addressing An addressing scheme whereby reference to an address is made by some convenient symbol that (preferably) has some relationship to the meaning of the data expected to be located at that address. It serves as an aid to the programmer.

Which of the following is are stored in a symbolic address?

The variable names, constants, and instruction labels are the basic elements of the symbolic address space. At the time of compilation, a compiler converts symbolic addresses into relative addresses. The loader generates these addresses at the time when a program is loaded into main memory.

Why do we use absolute addressing?

Absolute references There may be times when you do not want a cell reference to change when filling cells. Unlike relative references, absolute references do not change when copied or filled. You can use an absolute reference to keep a row and/or column constant.