Single-chip microcomputer refers to the program counter (Programs Counter). The program counter PC is used to store the next instruction address to be executed, is a 16-bit dedicated register, can not be manipulated by the MOV instruction, is not visible to the user. When executing an instruction, it is necessary to take the instruction out to the instruction register according to the address of the instruction stored in the PC, which is called "Fetch instruction". At the same time, the address of the PC in the program to automatically add 1 jump operation, to get the next point of the address. After the execution of the current instruction, the CPU then takes the address of the next instruction from the PC, and then gets the address of the next instruction, then executes each instruction sequentially.
Single chip microcomputer PC pointer