hardware (PC, or "instruction address register") A

register in the central processing unit that contains the

addresss of the next instruction to be executed. The PC is

automatically incremented after each instruction is fetched to

point to the following instruction. It is not normally

manipulated like an ordinary register but instead, special

instructions are provided to alter the flow of control by

writing a new value to the PC, e.g. JUMP, CALL, RTS.