COA by Athar Mohsin

Introduction

Lecture 02

COA by Athar Mohsin

Introduction

• Advancement in computer system related to development of high performance 16-bit, 32 bit and 64 bit microprocessor architecture and microcomputer system– IBM PC – the first microcomputer 1981, a 16 bit MP 8088– Few years later PC/AT: personal computer advanced

technology, 80286– Intel’s 80486: the first 32 bit MP– Today Pentium IV based PC/AT industry standard

• Advancement is due to VLSI technology • 50,000 or more software are available for these PC

COA by Athar Mohsin

Why study computer organization and architecture?– Design better programs, including system software such as

compilers, operating systems, and device drivers

• Writing complex program and algorithm- need a computer run efficiently

• Some algorithms infeasible today-could be feasible tomorrow

– Current rate of innovation predict this

– Optimize program behavior

• Why the implementation of feasible algorithm running slowly

– See the program from computer’s point of view

– Understanding of computer working is important

– Evaluate (benchmark) computer system performance

• Concept of benchmarking is important for computer professional

• How hardware interact with the software

• Understand time, space, and price tradeoffs.

Overview

COA by Athar Mohsin

Architecture & Organization

• Architecture is those attributes visible to the programmer– Instruction set, number of bits used for data

representation, I/O mechanisms, addressing techniques.• e.g. Is there a multiply instruction?

– All Intel x86 family share the same basic architecture

• Organization is how features are implemented– Control signals, interfaces, memory technology.

• e.g. Is there a hardware multiply unit or is it done by repeated addition?

– Organization differs between different versions

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Overview

• Computer organization– Addresses issues such as control signals (how the computer

is controlled), signaling methods and memory types– Encompasses all physical aspects of computer systems.

• E.g., circuit design, control signals, memory types.

– How does a computer work?

• Computer architecture– Focus on the structure and behavior of the computer system and – Refer to Logical aspects of system implementation as seen by

the programmer.• E.g., instruction sets, instruction formats, data types, addressing

modes.

– How do I design a computer?

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Computer Components

• There is no clear distinction between matters related to computer organization and matters relevant to computer architecture.– In microcomputers the distinction is very close

• Changes in technology influence both organization and architecture

• Principle of Equivalence of Hardware and Software:– Anything that can be done with software can also be done with

hardware, and anything that can be done with hardware can also be done with software.*

• Many computer manufacturers offers a family of computer models– All Intel x86 family share the same basic architecture– The IBM System/370 family share the same basic architecture– This gives code compatibility

• At least backwards– Organization differs between different versions

* Assuming speed is not a concern.

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• At the most basic level, a computer is a device consisting of three pieces:

– A processor to interpret and execute programs

– A memory to store both data and programs

– A mechanism for transferring data to and from the outside world.

Computer Components

COA by Athar Mohsin

Open System Architecture• The IBM personal computer (PC)- in 80s the earliest

microcomputer that used a 16 bit microprocessor – 8088• IBM PC’s success is due to “open system Architecture”

– The functionality of the PC expands by simply adding boards into the system

• Add on memory, modem, serial communication interfaces and local area network interfaces

– System expansion is enabled by the PC’s expansion bus• 8-bit expansion bus standard – I/O channel

• 16- bit high performance I/O expansion bus “ industry standard architecture – ISA, PC/AT

• New high speed bus architecture “peripheral component interface- PCI bus, has replaced ISA in P-IV and support 32 bit and 64 bit data transfer

– PCI permits connection of high performance I/O interfaces, such as » Graphics , video and high speed local area network (LAN)» Data transfer rate is 10 times faster than ISA bus

COA by Athar Mohsin

Open System Architecture

• Reasons of success – Open System architecture

• PC power can be extended by adding boards into the system– Modem, additional memory, serial communication and LAN

– Known as interfacing peripherals to the system

• System expansion is enabled by PC’s expansion bus– 8 bit expansion bus: I/O channel, allow add ins products

» ISA: industry Standard Architecture

– 32-bit and 64-bit data interface, PCI: Peripheral Component Interface

» High speed LAN, graphic and video

» Data transfer rate is 10 times faster than ISA

– Microcomputer– Mini computer– Main frame computer

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Main, mini & micro • Mainframe

– Used in the environment where it serve for large number of users

• University or where large data processing is a requirement

• Minicomputer– Large number of users accessing some central machine

through dumb terminal– Not self sufficient computers, if central machine is not

working no terminal will also be working

• Microcomputer– Known as PC, designed for used by individual as

standalone or through connected through LAN– It is a general purpose electronic data processing machine

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General Architecture

• The hardware of a microcomputer system can be divided in four functional sections– The input unit– The microprocessor unit– The memory unit– The output unit

• Each unit has a special function• The communication medium that is linking these

units is bus– The address bus– The data bus – The control bus

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General Architecture of microcomputer

Secondary Storage memory

ProgramStoragememory

DataStoragememory

Primary Storage memory

Inputunit

Microprocessorunit

Outputunit

The heart of microcomputer system, implemented with a VLSI device – “ Microprocessor or just Processor ” A general purpose processing unit built into a single IC

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General Architecture of microcomputer• General Architecture of microcomputer:

– The input and output unit– The memory unit

• Program storage memory• Data storage memory• Secondary storage memory

– Each unit has a specific function in the system • The microprocessor unit, the heart of the system, implemented

with a VLSI device, built into an IC– Responsible to perform all arithmetic operations and taking logic

decisions based on software program

• I/O units communicate with outside world• Memory unit: to store information

– Hold the information for processing or for outputting at a later stage – Memory can be categorized as

» Primary storage and secondary storage

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Microcomputer Architecture

• Secondary storage– Long term storage that is not currently being used

• CD, DVD, Floppy, HDD and tape• 512 MB to 100 GB and more

• Primary storage– Normally smaller in size and used for temporary storage

of active information• Operating system, the currently running program, the data

currently being processed – Program storage section: store instructions of Operating system and

application program– Data Storage section: normally contains data that are to be

processed by the program as they are executed

– Primary storage is implemented with RAM and ROM• Volatile and non volatile in nature

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Consider this advertisement:

An Example System

MHz??

MB??

PCI??USB??

L1 Cache??

What does it all mean??

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An Example System

A system bus moves data within the computer. The faster the bus the better. This one runs at 400MHz.

The microprocessor is the “brain” of the system. It executes program instructions. This one is a Pentium (Intel) running at 4.20GHz.

DDR SDRAM or Double-Data-Rate Synchronous Dynamic Random Access Memory is a class of memory integrated circuit. It achieves greater bandwidth than the single-data-rate SDRAM by transferring data on the rising and falling edges of the clock signal.

COA by Athar Mohsin

Microprocessor

• Part of computer that actually executes program instructions refers as Brain of computer

• Every computer consists of clock that keep system synchronized– It sends electrical pulses simultaneously to main

components • Ensuring that data and instructions are there where they are

supposed to be at one time – Measured in Hz

– As there is nothing gets done in computer without the involvement of microprocessor

• Frequency rating of microprocessor is crucial to overall system speed

– 4.20 GHz

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Program execution

• The fact that microprocessor runs at 4.20 GHz, however it does not mean that it can execute 4.20 billion instructions every second – Some instructions required one clock cycle to run while

some need more than one

• The number of clock cycle required to carry out a particular machine instruction is a function of – Machine organization and – Machine architecture

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An Example System

… and two levels of cache memory, the level 1 (L1) cache is smaller and (probably) faster than the L2 cache. Note that these cache sizes are measured in KB.

This system has 256MB of (fast) synchronous dynamic RAM (SDRAM) . . .

400MHz refer to the speed of system bus, that moves data and instructions to various places

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An Example System

• Computers with large main memory capacity can run larger programs with greater speed than computers having small memories.

– 256MB or about 256 million character refers to memory capacity

– Determine the size of the program that can be run, and how many program can be run

• RAM is an acronym for random access memory. Random access means that memory contents can be accessed directly if you know its location

– SDRAM short for synchronous dynamic random access memory much faster as it synchronize itself with microprocessor bus

• Cache is a type of temporary memory that can be accessed faster than RAM.

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Cache memory

• Cache is a type of temporary memory that can be accessed faster than RAM

– 32 KB L1 cache small, fast memory that is built into the microprocessor chip and help speed up access to frequently used data

– 256 KB L2 cache is a collection of fast, built-in memory chips situated between microprocessor and main memory

COA by Athar Mohsin

An Example System

This one can store 80GB. 7200 RPM is the rotational speed of the disk. Generally, the faster a disk rotates, the faster it can deliver data to RAM. (There are many other factors involved.)

Hard disk capacity determines the amount of data and size of programs you can store.

Advanced Technology Attachment (ATA) is a standard interface for connecting storage devices

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An Example System

ATA stands for advanced technology attachment, which describes how the hard disk interfaces with (or connects to) other system components.

A CD can store about 650MB of data. This drive supports rewritable CDs, CD-RW, that can be written to many times.. 48x describes its speed.

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An Example System

This system has ten ports.

Ports allow movement of data between a system and its external devices.

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Example System

• Serial ports send data as a series of pulses along one or two data lines.

• Parallel ports send data as a single pulse along at least eight data lines.

• USB, Universal Serial Bus, is an intelligent serial interface that is self-configuring. (It supports “plug and play.”)

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An Example System

System buses can be augmented by dedicated I/O buses. PCI, peripheral component interface, is one such bus.

This system has three PCI devices: a video card, a sound card, and a data/fax modem.

COA by Athar Mohsin

An Example System

The number of times per second that the image on a monitor is repainted is its refresh rate. The dot pitch of a monitor tells us how clear the image is.

This one has a dot pitch of 0.24mm and a refresh rate of 75Hz.

The video card contains memory and programs that support the monitor.

Peripheral Component Interconnect, a local bus standard developed by Intel Corporation.

COA by Athar Mohsin

Measures of capacity and speed:• Kilo- (K) = 1 thousand = 103 and 210

• Mega- (M) = 1 million = 106 and 220

• Giga- (G) = 1 billion = 109 and 230

• Tera- (T) = 1 trillion = 1012 and 240

• Peta- (P) = 1 quadrillion = 1015 and 250

• Exa- (E) = 1 quintillion = 1018 and 260

• Zetta- (Z) = 1 sextillion = 1021 and 270

• Yotta- (Y) = 1 septillion = 1024 and 280

An Example measuring System

Whether a metric refers to a power of ten or a power of two typically depends upon what is being measured.

COA by Athar Mohsin

• Hertz = clock cycles per second (frequency)– 1MHz = 1,000,000Hz– Processor speeds are measured in MHz or GHz.

• Byte = a unit of storage– 1KB = 210 = 1024 Bytes– 1MB = 220 = 1,048,576 Bytes– Main memory (RAM) is measured in MB– Disk storage is measured in GB for small systems, TB for

large systems.

An Example measuring System

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An Example measuring System

Measures of time and space:• Milli- (m) = 1 thousandth = 10 -3 or 2 -10

• Micro- () = 1 millionth = 10 -6 or 2 -20

• Nano- (n) = 1 billionth = 10 -9 or 2 -30

• Pico- (p) = 1 trillionth = 10 -12 or 2 -40

• Femto- (f) = 1 quadrillionth = 10 -15

• Atto- (a) = 1 quintillionth = 10 -18

• Zepto- (z) = 1 sextillionth = 10 -21

• Yocto- (y) = 1 septillionth = 10 -24

If we want to talk about how fast something is, we speak in terms of fractions of second- thousandths, millionths or trillionth

Shown as exponents

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• Millisecond = 1 thousandth of a second– Hard disk drive access times are often 10 to 20

milliseconds.

• Nanosecond = 1 billionth of a second– Main memory access times are often 50 to 70

nanoseconds.

• Micron (micrometer) = 1 millionth of a meter– Circuits on computer chips are measured in microns.

An Example System

COA by Athar Mohsin

• There are many organizations that set computer hardware standards-- to include the interoperability of computer components.

• Throughout this course, and in your career, you will encounter many of them.

• Some of the most important standards-setting groups are:– The Institute of Electrical and Electronic Engineers (IEEE)

• Promotes the interests of the worldwide electrical engineering community.

• Establishes standards for computer components, data representation, and signaling protocols, among many other things.

Standards Organizations

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• The International Telecommunications Union (ITU)

– Concerns itself with the interoperability of telecommunications systems, including data communications and telephony.

• National groups establish standards within their respective countries:

– The American National Standards Institute (ANSI)

– The British Standards Institution (BSI)

• The International Organization for Standardization (ISO)

– Establishes worldwide standards for everything from screw threads to photographic film.

– Is influential in formulating standards for computer hardware and software, including their methods of manufacture.

Standards Organizations