3 MODULE 2.2 -COMPUTER MEMORY.ppt

Amity School of Engineering & Technology
In this chapter you will learn about:
Internal structure of processor
Memory structure
Determining the speed of a processor
Different types of processors available
Determining the capacity of a memory
Different types of memory available
Several other terms relatedto the
processor and main memory of a computer
system
Learning Objectives

Block Diagram of Computer
• Functional block diagram consists of three
basic units:
1) Input/Output devices
2) System Unit
3) Storage Unit
• Computer hardware system consists of
different types of devices. Each device is
connected directly or indirectly to the
motherboard. These are classified into three
basic categories:

• Input/Output Devices: User enters the commands
and data through the keyboard or mouse, these data
are translated into a form that computer can process.
After processing the data, output devices converts it
into human understandable format.
Ex. Commonly used input/output devices are keyboard,
mouse, monitor and printer.

• System Unit : Also called as system cabinet contains
the most of the electronic components that make up a
computer system. Important component is processor,
which controls and manipulates data to produce
information. Clock is used to synchronize the whole
circuitry of the system.
• RAM (Random Access Memory) use to store
temporarily data to read or write data onto the
disk/memory. ROM (Read Only Memory) contains
permanently stored programs such as monitor
programs. Expansion slots are available on
motherboard to enhance computer system by using
graphics cards, sound cards, TV tuner card etc. Ports
are connecting sockets on the system unit like monitor
port, printer port, USB port, RJ45 port and audio port.

• Storage Unit : Attached hard disk inside the cabinet is
mainly used as storage device, as it can store more
data and faster than CD drive. But still CD (Compact
disc) and DVD (Digital Video Disc) are used to store
and transfer data from one pc to another.

CPU (Central Processing Unit)

• It's a microprocessor chip developed by Intel, AMD or any
other company.
• CPU speed depends upon the clock frequency, higher the
clock frequency more number of instructions can be
executed per second.
• Clock frequency is measured in MHz or GHz.
• CPU word size is the largest number of bits that can be
handled by CPU in one clock cycle. It is either 8, 16, 32, 64
or 128 bit.
• This word size value determines number of bit processor
i.e. 8-bit processor, 16-bit processor, 32 bit processor etc.
• CPU performance also depends upon the RAM, bus speed
and cache size as well.
• Called as heart of the computer.

Working
• CPU consists of three basic units: control unit,
Arithmetic Logical Unit (ALU) and memory unit.
• Input is given through the input devices to CPU.
• Control unit controls communication within ALU and
memory unit.
• Decides which circuit is to be activated.
• For reading instruction it uses Fetch-execute
mechanism.
• Control unit gets instruction from memory.
• Control unit decides what to do of that instruction and
transfers it to the ALU.

• ALU performs various arithmetic operations like
addition, subtraction, multiplication, division and
logical operations like AND, OR, NOT, NAND etc. on
that instruction.
• Results of ALU are stored in the memory or resistor
for its further operations.
• After completing the instruction, stored results are
passed to the output devices.
• To synchronize all these operations CPU uses its own
system clock.

What it does?
• Executes stored instructions called as
program.
• Tells rest of the computer system what to do.
• Executes arithmetic calculation and data
manipulation.
• Holds data and instruction which are in the
current use.
• Responsible for storing and retrieving
information on disks and other media.

 The brain of a computer system
 Performs all major calculations and comparisons
 Activates and controls the operations of other units of a
computer system
 Two basic components are
 Control Unit (CU)
 Arithmetic Logic Unit (ALU)
 No other single component of a
computer determines its overall performance as much
as the CPU
Central Processing Unit (CPU)

Control Unit (CU)
• One of the two basic components of CPU
• Act as the central nervous system of a computer System
• Select and interprets program instructions, and coordinate
execution
• Has some special purpose registers and a decoder to perform
these activities

 One of the two basic components of CPU.
 Actual execution of instructions takes place in ALU
 Has some special purpose registers
 Has necessary circuitry to carry out all the
arithmetic and logic operations included in the CPU
instruction set
Arithmetic Logic Unit (ALU)

Motherboard
• A small or large circuit board inside a cabinet
containing most of the electronic components.
• Everything connected to the computer is directly or
indirectly plugged into motherboard. Components like
CPU, BIOS, ROM, RAM, chips, and CMOS setup
information.
• Expansion slots for installing different cards like video,
sound, graphics, and NIC.
• Also contains RAM slots, system chipset, controllers
and underlying circuit to tie it together.

Types of motherboard
Non-integrated:
• Assemblies such as I/O port connectors, hard drive
connectors, CD drive connectors etc installed as
expansion boards.
• Takes lot of free space inside the case because of
expansion slots.
• If something goes wrong such as bend or broken pin
or defective controller can be repaired with minor
cost.
• Are cheap and easy to produce.
• Most of the olden motherboards were non-integrated.

Integrated:
• Assemblies are integrated or built right onto the
board.
• Serial and parallel ports, IDE, CD drive are directly
connected to the motherboard.
• This tends to free some space inside case and better
accessibility to the components.
• Cheaper to produce but are expensive to repair.
• Fast, powerful, feature rich motherboard at reasonable
price.

Motherboard form factors:
• Determines general layout, size and feature placement
on the motherboard.
• Form factors such as physical size, shape, component
placement, power supply connectors etc.
• Various form factors of motherboards are AT(Advanced
Technology), Baby AT, ATX(Advanced Technology Extended),
Mini-ATX, Micro-ATX, Flex ATX, LPX(Low Profile Extension)
and Mini LPX and NLX(New Low Profile Extended).

What was the first motherboard?
• The first motherboard is considered to be one
used in the IBM Personal Computer, released
in 1981. At the time, IBM called it a "planar"
instead of a motherboard. The IBM Personal
Computer and the motherboard inside it would
set the standard for IBM-compatible computer
hardware going forward

Best Motherboards
1. Asus ROG Maximus XII HERO - best Intel motherboard
2. MSI MEG Z490 Godlike - best high-end Intel motherboard
3. GIGABYTE Z490 Gaming X - best budget Intel motherboard
4. MSI MPG Z390M Gaming Edge AC - best Intel micro-ATX
motherboard
5. Asus ROG Strix Z390-I Gaming - best Intel mini-ITX
motherboard
6. ASRock X570 Phantom Gaming X - best AMD motherboard
7. Aorus X570 Master - best high performance AMD
motherboard
8. Asus ROG Strix B550-E Gaming - best budget AMD
motherboard
9. Asus TUF Gaming B550M-PLUS - best AMD micro-ATX
motherboard
10.ASUS ROG Strix X470-I - best AMD mini-ITX motherboard

 Memory capacity of a computer is equal to the number
of bytes that can be stored in its primary storage
 Its units are:
Memory Capacity
Kilobytes (KB) : 1024 (210) bytes
Megabytes (MB) : 1,048,576 (220) bytes
Gigabytes (GB) : 1,073,741824 (230) bytes

 Primary storage of a computer is often referred to as RAM
because of its random access capability
 RAM chips are volatile memory
 A computer’s motherboard is designed in a manner that
the memory capacity can be enhanced by adding more
memory chips
 The additional RAM chips, which plug into special sockets
on the motherboard, are known as single-in-line memory
modules (SIMMs)
Random Access Memory (RAM)

What Is RAM?
RAM stands for Random Access Memory, and it gives
computers the virtual space needed to manage
information and solve problems in the moment. You can
think of it like reusable scratch paper that you would
write notes, numbers, or drawings on with a pencil. If
you run out of room on the paper, you make more by
erasing what you no longer need; RAM behaves
similarly when it needs more space to deal with
temporary information (i.e. running software/programs).
Larger pieces of paper allow you to scribble out more
(and bigger) ideas at a time before having to erase;
more RAM inside of computers shares a similar effect.

A small scale size IC's memory chip used to store and
access data in any order (i.e. in random order), so the
name Random Access Memory.
Description
• Also called as temporary or volatile memory.
• Holds the program and data, which are currently
processing.
• Data is lost as soon as computer is turned off or
power failure.
• Data stored in this memory can be altered or changed.

Types of RAM
SRAM (Static RAM):
• Fast and has less access time.
• Consists of flip-flop using either transistor or MOS
(Mosfet).
• For each bit it requires one flip-flop.
• Status of each bit remains as it is unless there is write
operation or power is off.
• e.g. Cache memory.
• Advantages
Refreshing circuit is not required.
• Disadvantages
Costly and low package density.
Requires more space.

DRAM (Dynamic RAM):
• Slower and higher access time
• Data is stored in the form of capacitors.
• Capacitors charges when data is 1 and doesn't charge
if data is 0.
• Because of leakage current in capacitor, they need to
be refreshed to hold the data in memory cells.
• Refreshing is the process in which the contents of
each memory cell is read and written hundred times a
second.
• This maintains the data of memory cells in capacitor.
• e.g. Main memory.
Advantages
Cheaper than static RAM.
Disadvantages
Requires refreshing circuit.

LATESR RAM
• DDR4 SDRAM is the abbreviation for "double data rate fourth
generation synchronous dynamic random-access memory",
the latest variant of memory in computing.
... DDR4 chips are expected to support transfer rates between
2133 MT/s (million transfers per second) and 4266 MT/s.
• https://youtu.be/PVad0c2cljo

• Normally RAM comes in 4GB, 8GB and 16GB
Slots Samsung sells a single 32GB stick of
DDR4 RAM, but it's quite expensive. The
maximum you'll see in the wild is usually
16GB.

ROM (Read Only Memory)
• Also called as non-volatile memory.
• Holds the permanent programs to tell system
how to use circuit board.
• Data is not lost even the computer is switched
off or power failure.
• Data in this memory is read only.

Type Usage
• MROM (Mask-programmed
ROM)
• It is programmed at the factory.
• Program or data is permanently installed
at the time of manufacturing.
User-programmed ROM
or
Programmable ROM (PROM)
• Can be custom-programmed by the user
only once using special circuitry PROM
programmer.
• This circuit uses high voltages to
permanently eliminate or create inner
links.
Erasable PROM (EPROM)
Can be programmed by the user using
strong ultraviolet light and special circuitry.
Types of ROMs
(Continued on next slide)

Type Usage
Electrically EPROM
(EEPROM)
• Can be erased and reprogrammed by
electrical signals.
• Manufacturing process is complex and
expensive.
• Rarely used.
Types of ROMs

 It is commonly used for minimizing the memory-
processor speed mismatch.
 It is an extremely fast, small memory between CPU
and main memory whose access time is closer to the
processing speed of the CPU.
 It is used to temporarily store very active data and
instructions during processing.
Cache is pronounced as “cash”
Cache Memory

Hard drive/ Hard disk drive
A hard disk drive (sometimes abbreviated as a hard
drive, HD, or HDD) is a non-volatile data storage
device. It is usually installed internally in a computer,
attached directly to the disk controller of the
computer's motherboard. It contains one or
more platters, housed inside of an air-sealed casing.
Data is written to the platters using a magnetic head,
which moves rapidly over them as they spin.

• The first hard drive was introduced to the market
by IBM on September 13, 1956. The hard drive was
first used in the RAMAC 305 system, with a storage
capacity of 5 MB and a cost of about $50,000
• 1983 marked the introduction of the first 3.5-inch size
hard drive, developed by Rodime. It had a storage
capacity of 10 MB
• Seagate was the first company to introduce a
7200 RPM hard drive in 1992. Seagate also introduced
the first 10,000 RPM hard drive in 1996 and the first
15,000 RPM hard drive in 2000.

Can a computer work without a hard drive?
Without a hard drive, a computer can turn on and POST.
Depending on how the BIOS is configured,
other bootable devices in the boot sequence are also
checked for the necessary boot files. For example, if
the USB device is listed in your BIOS boot sequence, you
can boot from a bootable USB flash drive in a computer
without a hard drive.

How is a hard drive connected to a computer?
• An internal hard drive connects to the
computer using two means: a data cable
(IDE, SATA, or SCSI) to the motherboard and
a power cable to the power supply.
• The vast majority of drives in use today
connect through a standard interface called
Serial ATA (or SATA). Specialized storage
systems sometimes use Serial Attached SCSI
(SAS), Fibre Channel.

The Solid State Drive (SSD)
• Solid state is industry shorthand for an integrated circuit, and
that’s the key difference between an SSD and a HDD: there
are no moving parts inside an SSD. Rather than using disks,
motors and read/write heads, SSDs use flash memory instead
— that is, computer chips that retain their information even
when the power is turned off.
• SSDs provide a huge performance advantage over hard drives
— they’re faster to start up, faster to shut down, and faster to
transfer data.

• Many SSD makers produce SSD mechanisms that are
designed to be plug-and-play drop-in replacements for 2.5-
inch and 3.5-inch hard disk drives because there are millions
of existing computers
• Intel’s 32 TB P4500. Resembling a standard 12-inch ruler,
the Intel SSD DC P4500 has a 32 terabyte capacity

Laptop makers adopted the mSATA, and then the M.2 standard,
which can be as small as a few squares of chocolate but have
the same capacity as any 2.5” SATA SSD.

• Another interface technology called NvM Express or NVMe may start to
move from servers in the data center to consumer laptops in the next few
years
• As of August 2020, desktop hard disk drives typically had a capacity of 1 to
8 terabytes, with the largest-capacity drives reaching 20 terabytes (single-
disk drives, "dual" drives are available up to 24 TB). Smaller, laptop internal
2.5-inch drives, are available up to 5 TB.
• Nimbus Data made (Exadrive) 100 TB SSD cost $40,000 or about Rs 30
lakhs
• Samsung 860 EVO with 2 TB space is highest capacity SSD with M.2 slot.

Key Words/Phrases
 Accumulator Register (AR)
 Address
 Arithmetic Logic Unit (ALU)
 Branch Instruction
 Cache Memory
 Central Processing Unit (CPU)
 CISC (Complex Instruction Set
Computer) architecture
 Clock cycles
 Clock speed
 Control Unit
 Electrically EPROM (EEPROM)
 Erasable Programmable Read- Only
Memory (EPROM)
 Explicitly Parallel Instruction
• Computing (EPIC)
 Fixed-word-length memory
 Flash Memory
 Input/Output Register (I/O)
 Instruction Register (I)
 Instruction set
 Kilobytes (KB)
 Main Memory
 Manufacturer-Programmed ROM
 Megabytes (MB)
 Memory
 Memory Address Register (MAR)
 Memory Buffer Register (MBR)
 Microprogram
 Multi-core processor
 Non-Volatile storage Processor
 Program Control Register (PC)
 Programmable Read-Only Memory
(PROM)
 Random Access Memory (RAM)
114

Key Words/Phrases
114
(Continued from previous slide..)
Read-Only Memory (ROM)
Register
RISC (Reduced Instruction Set Computer)
architecture
Single In-line Memory Module (SIMM)
Ultra Violet EPROM (UVEPROM)
Upward compatible
User-Programmed ROM
Variable-word-length memory
Volatile Storage
Word length
Word size

3 MODULE 2.2 -COMPUTER MEMORY.ppt

Recommended

Recommended

More Related Content

Similar to 3 MODULE 2.2 -COMPUTER MEMORY.ppt

Similar to 3 MODULE 2.2 -COMPUTER MEMORY.ppt (20)

More from Vivek Parashar

More from Vivek Parashar (8)

Recently uploaded

Recently uploaded (20)

3 MODULE 2.2 -COMPUTER MEMORY.ppt