We have already seen how a computer is composed of. We have learnt about the block diagram of the computer, the input and output devices, the peripherals etc. We have seen that the computer with the help of CPU, the peripheral devices, has become quite powerful means of processing, storing and retrieving data. We have seen the overview of the working and composition of the computer; now let us look into the internal organization of computer in detail.
The circuit of computer is composed of electronic semiconductors which are placed on small piece of silicon. This is known as Integrated circuits (IC). With the revolution in technology, Large Scale Integration (LSI) and Very Large Scale Integration (VLSI) have come as a boon to the computer technology, reducing the size on one hand and increasing the processing capacity on the other hand. Thus the computers are becoming cheaper and cheaper from day to day with revolution in technology, thus generating an era of computer technology, where every aspect of life being influenced by computers.
Meaning of Central Processing Unit (CPU)
The basic component of a computer is the CPU, the strength and life of a computer. This is that component which does all the processing work. This CPU is mounted on the “Motherboard”, the main circuit of the computer. With the help of a micro processor chip the CPU performs the required arithmetic, logic and control functions. These micro processors are composed of circuits and storage locations, which are termed a registers. The mother board is connected to other circuits and peripheral devices with help of electrical lines known as buses.
The CPU’s performance, the strength of the computer, depends largely on the micro processors. The basic capability of processing depends on the following factors:
The Micro Processor: The basic component that affects the performance of a computer is the micro processor. There are different types of micro processors which are available; these micro processors are also changing with the changes in technology. The following are the commonly used micro processors:-
8 bit micro processor, 16 bit micro processor, 8/16 bit micro processor, 16/32 bit micro processor, 32/32 bit micro processor, 64 bit micro processor, 128 bit micro processor, 256 bit micro processor.
These processors are distinguished from one other in the way the data is handled and addressed. The configuration gives number of bits which are processed at a time. The most popular micro processors is 32/32 bit micro processor is mow replaced by the 64 bit Micro processor. The 128 and 256 bit micro processors are on their way to achieve wide acceptance and popularity. These processors are the core of the CPU, as they are the ones behind the processing capability of computer.
Speed of internal Clock: During the processing of instructions by the computer it undergoes two cycles. These cycles are mainly responsible for the processing. These cycles are termed as:
i) Instruction cycle: ii) Execution Cycle
These cycles are synchronized by the clock which produces electrical pulses. This clock is built in the processor itself, therefore it is called internal clock. As the cycles are synchronized by the electronic clock, the speed of the execution of these cycles depends on the clock’s speed. The cycle time is the time for executing a basic operation by the processor.
Primary Memory: Primary memory also plays a great role in the processing speed, as for any instruction to be executed; it has to be stored in the primary memory. If the capacity of primary storage is not sufficient, then the program has to be partly stored in secondary storage and partly into primary memory and it has to be swapped from the primary to secondary memory and vice versa, which reduces the speed of processors. Whereas, if the primary memory is quite sufficient to store the whole data and program, then the speed of processing increases to a great extent.
Design by Mohit Bhardwaj