address space

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The total range of distinct locations that may be referred to with the absolute address. For most (i.e. binary) machines it is equal to 2n, where n is the number of bits in the absolute address. The address space is often larger than the number of physical or real addresses that are present in the system, and some mapping scheme is necessary to obtain the physical address from the specified address. The physical address space embraces the primary memory, the I/O devices, and, in some cases, the registers in the CPU.

Subjects: Computing.

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