Electrical Engineering ⇒ Topic : Central Processing Unit (CPU)

CENTRAL PROCESSING UNIT (CPU)

The central processing unit (CPU) fetches instructions from memory and performs the assigned task. It stores the result in the memory or sends it to the output device as per the instructions given in the program. Figure (a) shows the schematic diagram of a CPU or microprocessor

                                    figure (a)   Schematic diagram of a CPU or Microprocessor.

The following are the main sections of CPU:

Arithmetic Logic Unit (ALU): It performs arithmetic operations such as addition and subtraction, logical operations such as AND, OR and EXCLUSIVE-OR.

Timing and Control Unit: It controls the entire operations of a computer. It acts as a brain and also controls all other devices connected to CPU.

Accumulator and General Purpose Registers: The accumulator is a register. It contains one of the operands and store results of most arithmetic and logical operations. The usage of general purpose registers is for temporary storage of data during execution of a program by a computer.

The CPU of a large computer is implemented on one or more circuitboards with ICs as its components.