CPU (Central Processing Unit): CPU is also called a processor. A processor is an electronic component in a digital computer that interprets instructions and processes contained in the computer programs. The CPU is also known as the heart of any computer because it is one of the most important components in a computer to perform any task.
The CPU fetches the instructions from the memory and performs a task.
The CPU stores the results in the memory or directly sends the results to the output devices according to the instructions given. The important sections of any CPU are as given below.
(1). ALU (Arithmetic Logical Unit): The ALU is a part of the execution unit. The main function of ALU is to perform arithmetic and logical operations. Some of the common operations of ALU are as given below.
(i): Integer arithmetic operations (Addition, Subtraction, etc.)
(ii): Bitwise logical operations (AND, OR, NOT, etc.)
(2). Timing Control Unit: This unit controls the entire operation of a computer as well as all the devices that are connected to the CPU. It generates the timing signals that are necessary for input and output devices to perform a task at a certain time.
(3). Accumulator: It is a register which stores results of arithmetic and logical operations.
(4). General Purpose Registers: These registers are used for the temporary storage of data and results while the computer is executing any task.
Main Memory: Main memory is the second important part of a digital computer after CPU. It contains a collection of storage locations, each with a unique identifier, called an address.
While performing a task in a computer, The data is transferred from the memory or to the memory in a group of bits called words. A word can be a group of 8 bits, 16 bits, 32 bits or 64 bits, etc.
Types of Memory: There are two main types of memory used in a computer.
(i): RAM (Random Access Memory)
(ii): ROM (Read Only Memory)