Central Processing Unit

This lesson will introduce you to the workings of a central processing unit.

The central processing unit (CPU) takes data from the main memory, processes it, and returns the modified data into the main memory. It comprises two subunits called the control unit (CU) and the arithmetic logic unit (ALU). As the name suggests, the arithmetic logic unit processes the data, whereas the control unit controls data flow to and from the main memory.

Control unit

The control unit coordinates the activities of all parts of a processor to ensure the desired results. It receives data from the main memory which it stores inside the registersRegisters are small (1 byte, 2 bytes, 4 bytes, etc.) storage elements referred to by different names inside a CPU." in the central processor.

One of the registers, called the program counter, contains the address of the current instruction in the main memory. Once the current instruction is completed, the value of the program counter is incremented by one. A program counter with the value of 2 is shown in ...

Two typical CPU registers