Brief Discussion Of IPO Cycle
For This We Have To Understand What Is CPU ?
Central Processing Unit
The processing of the data takes place in the Central
Processing Unit (CPU). It is present inside the CPU box/cabinet. It is known as
the brain of the computer. Apart from processing data it also stores data,
intermediate results, and instructions and controls the operation of all parts
of the computer. It consists of three components:
· Control
Unit
· Arithmetic
Logic Unit
· Memory
Unit
Control Unit (CU)
This unit controls the operations of all parts of the computer
but does not carry out any actual data processing operations i.e. it does not
process or store data. It is like the nervous system of the computer that:
· Controls
and regulates all the functions of the computer system
· Manages
the flow of data through input and output devices
· It gets
the instructions from the memory, interprets them and directs the operation of
the computer
Arithmetic Logic Unit (ALU)
This unit acts like an accountant that performs arithmetic
(addition, subtraction, multiplication and division) and logical calculations.
Memory Unit (MU)
This unit acts like a store house that stores information,
intermediate results of processing and the final results of processing before
the results are released to an output device. The information in the memory can
be edited, erased or retrieved whenever needed. The memory size affects speed,
power, and capability.
Types
of Computer Memory
The
computer memory is classified as follows:
v Memory
Primary/Internal
Ø ROM
§ PROM
§ EPROM
§ EEPROM
Ø RAM
·
SRAM
·
DRAM
v Secondary/External
·
HDD
·
CD
·
DVD
·
Pen
drive
Internal
memory
Internal memory is
also known as primary or main memory. It stores instructions and data on which
computer is currently working. Hence, it has limited storage capacity. As the
computer is turned OFF, data is lost.
Internal
memory has two parts:
vRAM (Random Access
Memory)
vROM (Read Only Memory)
RAM (Random Access Memory)
It is the read/write
memory and hence the information can be read from and written onto it.
RAM stores the data
that the user is using while working on the computer. Input data is stored in
this memory before it goes to the processor for actual processing. Also, when
you open a file, it is loaded in RAM.
This makes it easier
for the CPU to access the information. If the computer is switched OFF, the
data in its memory will be lost. RAM is therefore referred to as volatile
memory.
There are two types of
RAM:
Static RAM (SRAM) can
retain stored information as long as the power supply is ON. It need not be
refreshed. It has a long life, it is faster than Dynamic RAM, consumes high
power.
Dynamic RAM (DRAM)
stores information for a very short time (a few milliseconds) even though the
power supply is ON. It must be continually refreshed in order to maintain the
data. It has short data life, a moderate speed and consume less power.
Dynamic RAM (DRAM)
stores information for a very short time (a few milliseconds) even though the
power supply is ON. It must be continually refreshed in order to maintain the
data. It has short data life, a moderate speed and consume less power.
ROM (Read Only Memory)
It is the read only
computer memory from which information can only be read. It cannot be written
or erased.
ROM stores programs,
such as BIOS (Basic Input Output System) that are used for loading the
operating system. The information is not lost even when the power is switched
OFF. ROM is therefore, a non-volatile memory.
There are three types
of ROM:
Programmable Read Only
Memory (PROM) is programmable ROM. It can be modified only once or the data can
be written once but can be read many times. Once chip has been programmed, the
recorded information cannot be changed. PROM is also non-volatile memory.
Erasable Programmable Read Only Memory again. The information
can be erased by exposing (EPROM) chip can be programmed time and it to
ultra-violet light for a duration of up to 40 minutes.
Electrically Erasable
Programmable Read Only Memory (EEPROM) is programmed and erased electrically in
a millisecond. A single byte of a data or the entire contents of device can be
erased.
Know More
The
storage capacity of RAM may vary in different computers. Primary memory is the
working memory of the computer and works faster than secondary memory.
Computer
memory is where data is to be processed and instructions required for
processing are stored. The memory is divided into large number of small parts
called cells. Each location or cell has a unique address.
Cache
memory is a very high-speed memory which can increase the speed of the CPU. It
acts as a buffer between the CPU and the main memory. It holds data and
instructions frequently used by the CPU. The parts of data and instructions are
transferred from the disk to cache memory by the operating system, from where
the CPU can access them.
Cache
memory is faster than main memory as it stores data for temporary use and thus
takes less access time as compared to main memory. The disadvantage of cache
memory is that is it is expensive and has limited capacity.
Units
of measure for digital information
Memory units are used
to measure and represent data. Some of the commonly used memory units are:
Bit: The computer memory
units start from bit. A bit is the smallest memory unit to measure data stored
in main memory and storage devices. A bit can have only one binary value out of
0 and 1.
Byte: It is the fundamental unit to
measure data. It contains 8 bits or is equal to 8 bits.
External
memory
External memory is also called secondary or auxiliary memory.
The computer's memory is limited and temporary. Therefore, there is need to use
secondary storage devices. They help to store large amount of data permanently.
CPU directly does not access this memory, instead the data of secondary memory
is first transferred to the main memory, and then the CPU can access it.
Examples of secondary storage devices are, hard disk, CD, DVD, etc.
Units
of Computer Memory Measurements
·
1 Bit -> Binary Digit
·
4 Bits = 1 Nibble
·
8 Bits = 1 Byte
·
1024 Bytes = 1 KB (Kilo Byte)
·
1024 KB = 1 MB (Mega Byte)
·
1024 MB = 1 GB (Giga Byte)
·
1024 GB = 1 TB (Terra Byte)
·
1024 TB = 1 PB (Peta Byte)
·
1024 PB = 1 EB (Exa Byte)
·
1024 EB = 1 ZB (Zetta Byte)
·
1024 ZB 1 YB (Yotta Byte)
·
1024 YB 1 (Bronto Byte)
·
1024 Brontobyte = 1 (Geop Byte)
Geop Byte is The Highest Memory.
So,That’s all about IPO Cycle in this blog you have see some
more information about computer.
In Next blog I will let you know about Input, Output and
storage Devices.
Thank You!!
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