Briefly explain the organization of CPU

CPU Organization:

The fundamentals of CPU organization and operation are examined, along with the selection and formates of instructionand data types. The processor part of a computer CPU is sometimes reffered to as the data path of the CPU because the processor forms the paths for the data transfers between the resisters. The various paths are controlled by means of gates.

           In a well organized processor unit, the data paths ate formed by meand of buses and other common lines. The control gates that formulate the given path are essentially multiplexers and decoders whose selection lines specify the required paths.

All organizations emplya common ALU and shifter. The difference in organizations are mosly manifested in the organization of the resisters and their common path to the ALU.

Basic Functions:

The primary function of the CPU and other instruction set processors is to execute sequence of instructions, that is, programs, which are stored in an external main memory. Program execution is therefore carried out as follows:

• TheCPU transfers instructions and their input data from main memory to resisters in the CPU.

• The CPU executes the instructions in their stored sequence except when the execution sequence is explicitly altered by a branch instruction.

• The CPU transfers output data results from the CPU resisters to main memory.

Consequently, the streams of instrucitons and data flow between the external memory and the set of resisters that forms the CPU’s internal memory. The efficient management of these instrution and data streams is a basic function of the CPU.