The program counter (PC), commonly called the instruction pointer (IP) in Intel x86 and Itanium microprocessors, and sometimes called the instruction address register (IAR), the instruction counter, or just part of the instruction sequencer,Harry Katzan (1971), Computer Organization and the System/370, Van Nostrand Reinhold Company, New York, USA, LCCCN 72-153191 is a processor register that indicates where a computer is in its program sequence.
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