The computational and control unit of a computer is known as Central Processing Unit (CPU). It is the device that interprets and executes instructions.
Single chip central processing unit is called microprocessor. It made the existence of personal computers and workstations possible. The CPU or microprocessor, in the case of a microcomputer, has the ability to fetch, decode and execute instructions. It also transfers information to and from other resources over the computer's main data transfer path known as bus. By definition, the CPU is the chip that functions as the brain of a computer. Microprocessor or CPU is a piece of electronic circuit that uses digital logic to perform the instructions of program. The various components of CPU, which control the whole processing of the system, are:
• Semiconductors: Is a material that is neither a conductor nor an insulator but can be chemically altered to be either one, when required. A microprocessor is made of layer upon layer of electronic circuits that are liberally carved out of silicon. Silicon is the primary building block used in manufacturing the electronic circuits (chips). These silicon chips are used to conduct the processor and ultimately the computer or electronic circuits because it is an excellent semiconductor.
• Conductors and insulators: A conductor is the material or element or object, which allows electric current to pass through it such as copper or aluminum. These elements have free electrons through which the current can pass. While insulator does not allow an electrical current to pass through such as rubber or glass. Both the conductor and insulator are used in microprocessor accordingly.
• Integrated circuit: An Integrated Circuit (IC) is a combination of electronic components such as transistors, capacitors and resistors. It is designed to perform some logical functions based on timer, counter and memory. The basic building block of an IC is a logic gate. A logic gate performs the Boolean algebra.