This animation demonstrates the fetch-execute cycle where the next instruction is to be fetched from memory.
The program instruction is located at the address stored in the PC register. The instruction is fetched, brought
into the CPU over the data bus and stored in the IR register. Many instructions, when executed, involve the AC (accumulator) register. In this case, a datum is retrieved from the AC, processed in the ALU, and the result stored back in the AC.