As there are many variations in architecture between the different kinds of CPU, we shall begin my looking at an easy model of the structure.
The basic model consists of five parts, which are:
Arithmetic & Logic Unit (ALU)
The part of the central processing unit that contracts with operations for example addition, subtraction, and multiplication of integers and Boolean operations. It gets control signals from the control unit telling it to carry out these operations.
Control Unit (CU)
This manages the movement of instructions in and out of the processor, and also manages the operation of the ALU. It consists of a decoder, control logic circuits, and a clock to ensure everything happens at the right time. This is also responsible for performing the instruction execution cycle.
Register Array
this is a small amount of internal memory that is used for the rapid storage and retrieval of data and instructions. All processors include some common registers used for particular functions, namely the program counter, accumulator, instruction register, memory address register and stack pointer.
System Bus
it consists of control buses, data bus and address bus. It is used for connections among the processor, memory and peripherals, and transferable of data between the ranges of parts. .
Memory
The memory is not a real part of the CPU itself, and is instead housed elsewhere on the motherboard. Even if, it is here that the program being executed is stored, and as such is a crucial part of the overall structure occupied in program execution. For further information on the memory.