A central processing unit (CPU) is an important part of every computer. The CPU sends signals to control the other parts of the computer, almost like how a brain controls a body. The CPU is an electronic machine that works on a list of computer things to do, called instructions. It reads the list of instructions and runs (executes) each one in order. A list of instructions that a CPU can run is a computer program. A CPU can process more than one instruction at a time on sections called Cores. A CPU with four cores may process four programs at once. The CPU itself is made of three main components. They are:
The memory or storage unit stores vital information such as instructions, data, and intermediate results. The memory unit is responsible for transferring information to other units of the computer when needed. It is also known as an internal storage unit or the main memory or the primary storage or Random Access Memory (RAM) as all these are storage devices.
The control unit controls the operations of all parts of the computer but does not carry out any actual data processing operations. Its functions include: a) controlling the transfer of data and instructions among other units of a computer. b) managing and co-ordinating all the units of the computer. c) obtaining the instructions from the memory, interpreting them, and directing the operations of the computer. d) responsible for the communication with peripheral devices such as input and output devices.
The ALU, as can be seen, is made of two sections. They are:
- The Arithmetic Unit: It is responsible for the arithmetic operations such as addition, subtraction, multiplication and division. Any complicated actions are done by repeating the same steps over and over to achieve the final result
- The Logic Unit: As the name gives it away, it performs all the logical operations such as selecting, comparing, matching and merging of data