Definition of index register in English English dictionary
a specialpurpose register used by a processor when performing indexed addressing The value in the index register is usually the reference location to which a displacement will be added
A register that contains a quantity for modification of an address without permanently modifying the address
Also known as X, IX or by other names The register used to hold a value that becomes a factor in an indexed addressing mode Frequently used for arithmetic operations, though without as many capabilities as an accumulator