Indexregister

The index registers are special registers of a processor. In these offsets are stored to addresses for memory access, leap and jump back and run counter. In the theoretical design of the Von Neumann computer they are in spite function classified as data storage in computer work and provide the controller the ability to manage memory dynamically.

Using index register modification, it is possible to move away from static addressing and dynamic addressing memory cells. An index register allows it to access a memory address, the address of which was determined previously by other arithmetic operations for the duration of the program. High-level languages ​​have thus the possibility of fields and pointers to use.

Many modern computer architectures can use any general purpose register as the index register, which is the name often become obsolete.

Example

A abzulegender value in memory is at the 123 site of a particular memory block. The index register would in this case the value 123 (or 122 if counted as in the usual computer science from 0). The start address of the memory block is irrelevant, because this is in a different register. Addressing this stored in memory value will slightly decoupled from the actual location in memory because it is no longer directly, but given relatively ( relative to the start of the memory block ).