Download Memory

Chapter:4
Microprocessor Basic, Input, Output &
Memory Devices
Class: XI A
Microprocessor: A microprocessor is a
Central Processing Unit (CPU) on a single
chip. It is a multipurpose programmable
device constructed using Metal Oxide
Semiconductor (MOS) technology. It read
binary instructions from a storage device
called memory, accepts binary data as input
and processes data according to those
instructions and provides results as output.
Instruction Set: It is the set of instructions
that the microprocessor executes
Word Length(Bandwidth): The number of bits
processed in a single instruction is called word
length or word size. The word size is directly
proportional to the processing power of the CPU.
System Clock Speed: The System Clock is an
electronic circuit that generates pulses which are
measured in million of cycles per second (MHz). The
number of pulses generated by the clock per unit of
time is its Clock speed. Each microprocessor is
characterized by its clock speed. Nowadays
microprocessors have clock speed of several GHz.
The CPU uses this clock speed to control sequencing
and execution of various operations in the computer
Classification of Microprocessors
1.By bandwidth of the data format( 4-bit, 8bit, 16-bit, 32-bit, 64-bit, 128-bit): It
depends upon the size of the internal
registers and the word –size or the data
width they can process in one go.
2. By their instruction set: It is divided into
three types.
(a). RISC(Reduced Instruction Set Computer)
(b). CISC(Complex Instruction Set Computer)
(c). EPIC(Explicitly Parallel Instruction
Computing)
(a). RISC(Reduced Instruction Set Computer)
: It is a type of microprocessor architecture
that uses a small set of instructions of uniform
length. These are simple but primitive
instructions which execute in one clock cycle.
For this reason, RISC chips are less complex
and also less expensive to produce. The
instructions are of uniform length which
interface with about 32-36 registers.
Examples of RISC processor is SPARC,
POWER PC etc.
(b). CISC(Complex Instruction Set Computer)
:A CISC chip such as Intel Pentium provides
programmers with hundreds of instructions of
variable sizes, and the processing circuitry
includes many special purpose circuits that carry
out these instructions at high speeds. These
instructions interface with memory in multiple
mechanisms with complex addressing modes. In
this case the program size is reduced and hence
lesser number of memory cycles are required to
execute the instruction. So fewer general purpose
registers(8-12) are present in CISC processors.
Also less number of memory cycles result in faster
execution of the program.
(c).EPIC(Explicitly
Parallel
Instruction
Computing): It is a computer architecture
that combines the best feature of both RISC
and CISC. It does not use instructions of any
fixed length but rather aims at parallel
processing of instructions. It uses a bundle of
complex instructions that in addition to basic
instruction also contain information on how to
run the instruction in parallel with other
instructions. This greatly increases the
efficiency of an EPIC processor. IA-64 (Intel
Architecture-64) is Intel’s first 64 bit processor
based on EPIC.
=>Input Device: A device used to
provide data and instruction to the
computer are called input device.
Example: keyboard
1.Keyboard: It is used to enter both
numerical and characters type data. it
is like a mechanical typewriter with
alphanumeric and special keys.
• Mouse: A mouse is a pointing device that
functions by detecting two-dimensional
motion relative to its supporting surface.
The mouse's motion typically translates
into the motion of a cursor on a display,
which allows for fine control of a
Graphical User Interface.
Microphone(MIC): It is used to record
sound. It convert sound waves into audio
signals and vice versa.
• Output Device: When the data and
instructions are fed to the computer and
processed, the next step is to get the output.
This output may be displayed on the monitor
or printed on the paper.
 Softcopy output
 Hardcopy output.
=> Monitor: It is output device that display the
information on the screen. The quality of
pictures depends on the number of pixels that it
can display.
=> Types of Monitors:
1.Cathode Ray tube: The CRT works in the
same way as a television. It contains an
electron gun at the back of the glass tube. when
the electrons stakes the phosphors dots they
glow to give the colors
2. Liquid Crystal Display(TFT):Thin film
transistor is the device within each pixel that
sets the charge .
3. Plasma Monitors: it stand for PDP(Plasma display
Panels) are flat panel displays. It utilizes small cells
containing electrically ionized gases across the face
of a plasma display, to collectively form a visual image.
4.Touchscreen monitor: it build by combining touch
sensitive materials with a durable but sensitive outer
material that protects the monitor from finger but still
allows the monitor to detect where a person is placing
his fingers
5. Organic light emitting display(OLED) Monitors:
OLED monitors are created from pushing an electronic
current through organic material, causing these
materials to glow. It is extremely thin and light-weight
displays that can be worn on things like clothing.
 Printer:
A printer is an output device
which is used to transfer output data
from a computer onto paper.
Types of Printer
 There are two types of Printer
1.Impact Printer: There is mechanical
contact between the print head and
paper.
2.Non-Impact Printer: There is no
mechanical contact between the print
head and paper.
 Impact Printer divided into Two parts.
1.Line Printer
2.Character Printer(Serial Printer)
Line Printer prints a complete line at time
 Types of Line Printer
 There are two types of Line Printer
 Drum Printer: a drum printer consists of a
cylindrical drum on which characters are
embossed.
Chain printer: A chain printer consists of
a steel band on which the characters are
embossed. To print a line, the characters
in line are transmitted from the memory
to printer buffer Character.
printers(Serial Printer): Serial
character printer print one character
at a time ,with the print head moving
across a line
 Serial Printer divided into Two
Parts.
 1.Dot Matrix Printers: The printing
head contains a vertical array of
pins. As the head moves across the
paper, selected pins free against an
inked ribbon to form a pattern of
dots on the paper.
 2. Letter Quality Printers: The letter
quality printers print full characters
(continuous character not as the
character mode of dots)
Non-Impact Printers: The limitations
of speed in electromechanical
device and cost considerations have
led to the development of printers
called non-impact printers.
Type of Non-Impact Printers
1.Electromagnetic
printers:
A
magnetic image can be written on a
drum surface. then this surface is
passed through magnetic powder
which adheres to charged areas.
The powder is pressed onto the paper.
2.Thermal Printers: An electric pulse
can be converted to heat on selected
sections of a printing head or on
wires or nibs(heads). When this
head is applied to head sensitive
paper, a character is printed.
3. Electrostatic printers:
4. Inkjet printers: It is a character printers,
which form characters and all kinds of
images by spraying
small drops of ink on to the paper.
The print head of an inkjet printer
contains up to 64 tiny nozzles.
 Laser printer: Laser printers are
page printers, which print one page
at a time. The main components of a
laser printer are a laser beam
source, a multi-sided mirror, a
photoconductive drum and toner.
1.High speed 2.High quality output.
1.Cost. 2.maintenance cost is high.
Speakers:
Enhances
the
value
of
educational and presentation products.
Speakers receive the sound in the form of
electric current
from sound card and then
convert it to sound format.
Bit : A bits is a binary digit either a 0 or 1.
 Byte: A byte is a basic unit of memory
 A sequence of 8 bits.
 Word: A sequence of 16 bits or 2 bytes.
Memory
•
Essential component of computer, stores data, programs and
results.
• Three kinds of memory in modern computers:
1.Semiconductor
2.Magnetic 3.Optical memories
• Types of memories
1.Main memory
2.Secondary (Auxiliary) memory
Memory
Primary (Main) Memory
(Immediate access store(IAS))
RAM Memory
Static
Memory
Auxiliary (Secondary) Memory
ROM Memory
Dynamic
Memory
Masked ROM
PROM
EROM
EEROM
22
Semiconductor
Memory
Magnetic
Optical
WORM
RAM
ROM
CD-ROM
HARD
DISK
FLOPPY
DISK
TAPE
Memory: Memory is a device where data
and instructions are Stored and retrieve.
 Types of Memory
1.Main memory(Immediate access store(IAS))
2.Secondary memory
Main memory: It is the place where the
data and instructions supplied by the
input devices are stored.
It is a temporary because the data and
instructions stored are eased when power
cut off.
Primary memory is divided into a number of
memory cells (bits) or bytes.
A bit (binary digit) is the smallest storage unit
within a computer. It is a tiny electrical circuit that can
be in one of two states:
 A voltage high represented by the symbol 1
 A voltage low represented by the symbol 0
 Any system of symbols can be represented by bit
or byte patterns.
Each byte has a unique integer address and it is
usually 8 bits.
 Types of Main memory
There are two types
of
main
memory.
1.RAM(random Access Memory)
2.ROM(Read Only Memory)
 RAM: It is the read and write
memory. It is like a page notebook,
where write something to or read
something from.
Any memory location is accessed
randomly for reading and writing.
 It is a temporary because the data
and instructions stored are eased
when power Failure.
It is also known as Volatile Memory.
 It is Two Types
 1.Static RAM
 2.Dynamic RAM
Both are volatile
• Dynamic RAM made from MOS.
Charge must be continually refreshed in
order to maintain data. However, it is
cheaper, more compact than Static RAM.
• Dynamic Ram used for most primary
memory. Amount of data per chip has
increased rapidly.
• Memory Access Time: The amount of
time taken to produce data required from
memory , from the start of access until
the availability of data , is called memory
access time.
=>Static RAM is expensive, but does not
need to be refreshed, and is faster. Much
smaller data capacity on a chip (~256k).
=>Generally
made
using
bipolar
technology,
although
recently
have
developed
MOS
static
RAM.
=>SRAM is often used for cache memory,
because of its faster access time
Rom: It is a permanent memory. The data is
stored permanently and cannot be altered
by the programmer. It is also known as Field
Stores or Dead Stores.
Types of ROM
1.PROM(Programmable Read-Only Memory):
It is initially empty. Later, the user can store
programs ,data or any other information
permanently. However, these programs
cannot be erased once they are written to it.
2.EPROM(Erasable Programmable Read-Only
Memory): The Contents stored in this can
be erased by exposing it to ultra violet light
source for about 10-20 minutes.
then it is programmed, that is new
information can be stored.
3.EEPROM(Electrically
Erasable
Programmable Read-Only Memory):
The contents stored in this can be
erased
electrically.
Later
new
information is stored in it.
 It is also known as Flash Memory.
• Differences
RAM holds the programs and data
that the processor is actively
working with.
ROM contains software that is used
in Input/Output operations. It also
contains software that loads the
Operating System in Primary
Memory.
The CPU can read and write to
RAM but it can only read from ROM.
RAM is volatile while ROM is not.
Primary Memory
UNIT
SYMBOL
Byte
Kilobyte
POWER
OF 2
2
KB
Number of bytes
0
1
10
1,024
20
1,048,576
2
Megabyte
MB
2
Gigabyte
GB
30
2
1,073,741,824
Terabyte
TB
40
2
1,099,511,627,7
76
Primary and Secondary Memory
Comparison
Primary memory
Secondary memory
Fast
Expensive
Low capacity
Connects directly to
the processor
Slow
Cheap
Large capacity
Not connected directly
to the processor
Memory
•
The diagrams shown below represents the memory hierarchies as
per the speed of operation.
C
P
U
C
P
U
Primary
Memory
Cache
MEM
Primary
Memory
Secondary
Memory
Secondary
Memory
35
 Cache Memory: It is a high speed memory and
placed between the CPU and the main memory.
=>Users cannot access this memory. it stores
data and instructions that are currently to be
executed.
=>Cache memory contains a copy of frequently used
data/programs from main memory (ie it duplicates
some contents). When the CPU attempts to read a
word of memory , a cache controller checks to
determine if the word is in cache.
=>If present then word delivered to CPU (called a
hit); else (a miss) gets block from main memory and
loads it into cache, preserving locality of execution.
=>Hit ratio is hits to total requests
• Caching and virtual memory are both used to
improve cost/benefit performance of the
memory hierarchy.
• Caching improves memory access speed to
both primary and secondary storage by
predicting next required instructions/data &
storing it in faster memory (higher up
hierarchy).
• Virtual memory increases primary memory
capacity while decreasing cost by using
secondary memory as though it was RAM
(further down hierarchy)
 Secondary Memory: secondary storage
devices are used to store large amount of
data permanently for long-term .
 Types
1.Floppy Disks
2.Hard Disks
3.Magnetic tapes
4.Magnetic drum
5.CD-ROM
• Hard Disk: This is a high capacity storage device
ranging from 1GB to Tera Bytes .
• Concentric circles on the magnetized surface
of the magnetic disks are known as Tracks.
Each track is divided into 8 parts.
 Each of the 8 parts of a track is called a
Sector.
Sectors: The Tracks on the disk surface are
divided into invisible segments known as
sectors.
Cylinder:
Similar numbered tracks
on different platters of a hard disk
form a cylinder.
Hard Disk Example
Hard Disk Layout
Head
Block
Head
motor
Platter
Sector
Track
Cylinder
Track
Drive
motor
Head
assembly
Head, on
moving arm
Locating a Block of Data
Seek Time
Latency Time
Transfer Rate
Latency
Transfer
Head
Seek
Desired
track
Note: Access time = seek time + latency
Magnetic Disks
• A magnetic substance is coated on a round
surface
• The magnetic substance can be polarized in one
of two directions with an electromagnet (“writing
data”)
• The electromagnet can also sense the direction of
magnetic polarization (“reading data”)
• Similar to a read/write head on a tape recorder
(except the information is digital rather than
analogue)
Floppy Disks
• Also called “flexible disks” or “diskettes”
• The platter is “floppy”, or flexible (e.g.,
mylar)
• Most floppy disk drives can hold one
diskette (two surfaces)
• The diskette is removable
• Typical rpm: 300, 360
• Capacities: 700 KB to 1.4 MB (& up to 100
MB “zip” disks)
Floppy Disk Example
Access window
Shutter
Cutaway
showing disk
Case
Spindle
Write
protect tab
Digital Video Disk or Digital Versatile
Disk(DVD): DVD is a optical storage device .It
store more information and transfer it to the
computer very fast as a CD-ROM.
 DVDs come in two Formats:
 1.DVD-Video Format
 2.DVD_ROM Format.
 Blue Ray Disk(BD): It use a blue –violet
laser(450nm) is that it has a shorter wavelength
than a red laser(650 nm) , which makes it
possible to focus the laser spot with even
greater precision. It storage capacity 25
GB/50GB.
Ports: It is used to connect external
devices to the computer.
Serial Ports: Through this port the
information travels in and out one bit at a
time. Serial ports come in the form of 9-pin
or 25-pin male.
Parallel Ports. It can receive or send a
byte at a time.
USB(Universal serial Bus) Ports.
AGP(Accelerated graphic port) Ports: It
is used to Connect to graphic card that
provide high –speed video performance.
 InfraRed(IR)Ports: It sends or receive
infrared signas from other device.
 BlueTOOTH: It describes how mobile
phones and PDA can connected through
short range wireless connection . The
maximam range is 10 meters.
 Network Ports: It are used to enabled
Communications Between programs.
 Phone Ports: It is a port
that allows
connecting telephone equipment with the
computer sound card.
=> PS-2 Port: It stands for Personal System/2.
A PS/2 port is an electrical receptacle or plug
found on computers. It accepts a PS/2 cable
with a mini – DIN connector, and is used to
plug in a keyboard or mouse.
The World Wide Web
 One of the more popular segments of the Internet is the
World Wide Web, also called the Web.
 A Web page is a document that contains text, graphics,
sound, and/or video and has built-in connections, or
hyperlinks to other Web documents
 A Web site is a related collection of Web pages
 You access and view Web pages using a software program
called a Web browser
 A Web page has a unique address, called a Uniform
Resource Locator (URL)
 A hyperlink is a virtual connection to another place on
the Web
THE END