How it works
CPUs work on a cycle that is managed by the control unit and synchronized by the CPU clock. This cycle is called the CPU instruction cycle, and it consists of a series of fetch/decode/execute components. The instruction, which may contain static data or pointers to variable data, is fetched and placed into the instruction register. The instruction is decoded, and any data is placed into the A and B data registers. The instruction is executed using the A and B registers, with the result put into the accumulator. The CPU then increases the instruction pointer's value by the length of the previous one and begins again.
The basic CPU instruction cycle looks like this.
The basic CPU instruction cycle