Parts of the CPU

The processing component of the computer is called the central processing unit (CPU), or processor. It is the chip that performs all of the calculations necessary for the computer to do its job. Often called the brains of the computer, it is the device that makes computing possible.

ALU

The arithmetic logic unit (ALU) executes instructions and performs calculations (addition, subtraction, multiplication and division) and comparisons.

Control unit

The control unit directs the flow of data and instructions within the computer. It supervises or monitors the functions performed by the entire computer system according to conditions set forth by the stored program.

Registers

The registers, also known as cache, are temporary storage devices that hold data; they help the CPU in executing instructions by the repetition of machine cycles performed by the system clock.

System clock

The system clock generates precisely timed pulses of current that synchronize the processor's other components; it indicates the speed of the computer, as measured in megahertz (MHz) or gigahertz (GHz).

Machine Cycles

The function of CPU parts altogether consists of four repetitive steps, called machine cycle: the control unit fetches instruction and data from memory and decodes it, and then the ALU executes the instruction and stores the result in memory.

Resources

• How Computer Stuff Works?
• ACME Computer Guide