Fundamentals of Computer Organisation and Architecture Computer Architecture

Fundamentals of Computer Organisation and Architecture Computer Architecture Computer Science The Basic Computer Model Computers can do different things based on what they were made for Calculators calculate values Tills record and calculate money totals However, computers have evolved over time Originally just for number crunching Now can do lots of different things Were going to look at what a computer is, what a computer can do, and what a computer contains 2

Fundamentals of Computer Organisation and Architecture: Computer Architecture The Basic Computer Model Before going in-depth with these, we need to know one thing Different computers can do different things Theres a simple way to break this down The Input-Process-Output model Input 3 Process Fundamentals of Computer Organisation and Architecture: Computer Architecture

Output Computer Components More specifically, computers use Three Box Model Core requirements of a Computer Central Processing Unit Think Remember Communicate Bus Processor 4 Main Memory I/O Fundamentals of Computer Organisation and Architecture:

Computer Architecture Computer Components Central Processing Unit (CPU, a.k.a. Processor) Considered to be the brain of the computer Is a single, small chip (that can be quite fragile) Responsible for executing programs, performing basic operations, and supervising other components 5 Fundamentals of Computer Organisation and Architecture: Computer Architecture Computer Components Main Memory (IAS) Immediate Access Store (IAS) Stores Machine Code Sequences of code stored in Addresses

Program Instructions Data One or more Integrated Circuits Directly addressable unique locations by processor Memory Location = Separately addressable Multiple Memory Chips (512KB to 2Gb) RAM ROM EEPROM 1 Address = 1 Byte = 8 bits 6 Fundamentals of Computer Organisation and Architecture: Computer Architecture Computer Components Main Memory (RAM, ROM, EEPROM) Stores temporary/permanent data Values for a program

Machine code that will be executed on the CPU Accessed via addresses (binary numbers determined by CPU architecture) Comes in different types, chip sizes (both memory and physical size), and different speeds 7 Fundamentals of Computer Organisation and Architecture: Computer Architecture Computer Components Main Memory (RAM, ROM, EEPROM) RAM Random Access Memory Writable and readable stores for data But volatile RAM addresses are temporary, and only store data while the computer is powered on 8

Fundamentals of Computer Organisation and Architecture: Computer Architecture Computer Components Main Memory (RAM, ROM, EEPROM) RAM can be found in a few places Sticks of RAM for general data storage CPU can have a cache as well Caches are fast-access RAM stores used mostly by the CPU Allows the CPU to store frequently references data (like program instructions) Can speed up process time over storing this data in usual RAM 9 Fundamentals of Computer Organisation and Architecture: Computer Architecture Computer Components Main Memory (RAM, ROM, EEPROM)

ROM Read Only Memory Readable only Contains pre-made data/programs Often used to store a program that boots the operating system on the computer 10 Fundamentals of Computer Organisation and Architecture: Computer Architecture Computer Components Main Memory (RAM, ROM, EEPROM) EEPROM Electrically Erasable Programmable Read Only Memory Writable and readable, and non-volatile Data is permanently stored until overwritten or destroyed Writing over 100 times slower than reading from Flash Memory faster at writing than other types of EEPROM Blocks of bytes must be erased and written in one go rather than individual bytes

Comes in lots of different formats Examples include USB sticks, SD cards, and Solid-State Drives 11 Fundamentals of Computer Organisation and Architecture: Computer Architecture Computer Components EEPROM Flash Memory Mobile phone SIM Card Digital Camera MP3 player PDA Memory stick / Card Medical Electronics Solid State Drives Synthesisers 12

Fundamentals of Computer Organisation and Architecture: Computer Architecture Computer Components The System Bus External Bus also exists Transmits binary word between processor & store or I/O component Collection of signals which act together Set of parallel wires connect independent components to pass signals Three Buses Data Address Control

13 Fundamentals of Computer Organisation and Architecture: Computer Architecture Computer Components Bus Set of parallel of wires January 1989 Motorola 68030 16MHz Processor with: 32-bit internal registers, a 24-bit address bus, and a 16-bit data bus - http://www.theregister.co.uk/2010/11/09/macintosh_portable/page6.html 14 Fundamentals of Computer Organisation and Architecture: Computer Architecture Computer Components

Three buses Data Bus Bidirectional 32 0r 64 Wires Transports data Address Bus Unidirectional 32 or 64 Wires Signals from Processor address Memory and I/O Control Bus 15 Bidirectional

8 Wires Transports command signals Checks presence and condition of components Specifies timing and direction of data flow Fundamentals of Computer Organisation and Architecture: Computer Architecture Computer Components Control bus signals Signals Transmitted Clock Signal Digital tick (metronome) for timing purposes Reset Signal Used to initialise (wake) components before use Memory Read Asserts current memory location is being read from Memory Write Asserts current memory location is being written to I/O I/O and main memory occasionally share memory addresses

Asserts wish to use an I/O controller not main memory 16 Fundamentals of Computer Organisation and Architecture: Computer Architecture Computer Components Buses Address Bus Address used to specify a memory location E.g. 32-bit address needs 32 binary signals to specify location Signals are lumped together and called the address bus 16-bits wide in small processors / microcontrollers 32-bits & 64 bits wide in PCs, workstations, etc.

Data Bus Data transfers Same width as Processor registers / ALU Narrower reduces costs (pins, wiring, memory devices) Wider increases bandwidth (fetch two instructions in one cycle) Bandwidth is rate at which data is transferred Double Bandwidth Cycle Bus at twice the speed Double number of bits 17 Fundamentals of Computer Organisation and Architecture: Computer Architecture Computer Components - Bus Buses Address Bus Address used to specify a memory location

E.g. 32-bit address needs 32 binary signals to specify location Signals are lumped together and called the address bus 16-bits wide in small processors / microcontrollers 32-bits & 64 bits wide in PCs, workstations, etc. Data Bus Data transfers Same width as Processor registers / ALU Narrower reduces costs (pins, wiring, memory devices) Wider increases bandwidth (fetch two instructions in one cycle) Bandwidth is rate at which data is transferred Double Bandwidth Cycle Bus at twice the speed Double number of bits 18 Fundamentals of Computer Organisation and Architecture:

Computer Architecture Computer Components Input/Output Devices Help the user use a computer Input devices let the user interact with the computer Mouse and Keyboard Microphone Output devices let the computer show results/data to the user Monitor Speakers 19 Fundamentals of Computer Organisation and Architecture: Computer Architecture Computer Components Input/Output Devices

Controls data flow CPU Peripherals Peripherals not directly connected to Processor Every new Peripheral would require redesign of Processor I/O Controllers 20 Interface and translator for each Peripheral Specific I/O Controller for specific Peripheral device Reduced signal speed Operate as unidirectional (input / output only), or Bidirectional Fundamentals of Computer Organisation and Architecture: Computer Architecture

Computer Components I/O Controllers Three Parts Electronic interface between controller and System Bus I/O port set of registers for data, commands and status Written to / Read From Data Exchange Processor Peripheral Necessary electronics for sending control signals to connected peripherals 21 Fundamentals of Computer Organisation and Architecture: Computer Architecture Computer Components Central Processing Unit Processor Main Memory /

(IAS) Keyboard Keyboard Input Controller VDU Output Controller VDU (Disk) I/O Controller Secondary Store / Backing Store CPU communicates with peripheral devices through special communication tunnels (I/O controllers) 22 Fundamentals of Computer Organisation and Architecture:

Computer Architecture Computer Components Expanded three box model Signal Transmissions Which Direction? What is being transmitted? CONTROL BUS KEYBOARD CONTROLLER MAIN MEMORY PROCESSOR ADDRESS BUS DATA BUS

23 Fundamentals of Computer Organisation and Architecture: Computer Architecture VDU CONTROLLER MAGNETIC DISK CONTROLLER Computer Components Secondary Storage (Hard-Disk Drives and Solid-State Drives) Used to store permanent data on the computer The operating system Installed programs Day-to-day files

Slower at being accessed than Main Memory Examples include Hard-Disk Drives Solid-State Drives 24 Fundamentals of Computer Organisation and Architecture: Computer Architecture Fixed Program Computers Pre-1945 Punch Card Operations Fixed programs hard-coded Changes took days or weeks ENIAC took three weeks to rewire and rebuild (Electronic Numerical Integrator And Computer) Modern day Fixed program Computers Tools Calculator, Central Heating, Programmable Microwave Games PacMan, Tamagochi

25 Fundamentals of Computer Organisation and Architecture: Computer Architecture Von Neumann Architecture Von Neumann Hungarian Mathematician Contemporary of Albert Einstein Principal Member of the Manhattan Project Post-1945 Von Neumann Architecture Stored Program Concept Programs inside Computer NOT hardcoded Registers hold instructions and data semi-permanently Stored for repeated use Deleted / Replaced as required 26

Fundamentals of Computer Organisation and Architecture: Computer Architecture Stored program concept Program must be resident in main memory to be executed Machine code instructions are fetched one after another from main memory in sequence and are executed one at a time in the processor First Stored Program 1948 SSEM (Baby)

CRT Output 27 Fundamentals of Computer Organisation and Architecture: Computer Architecture Stored program concept Processor instructed to perform arithmetic and logical operations ADD, SUBTRACT, AND, OR Instructions represented by Binary / Machine Code Instructions and data stored in same way Bit pattern 01000110 could be number 4616 letter F Instruct Processor to perform addition 28 Fundamentals of Computer Organisation and Architecture:

Computer Architecture Stored program concept Von Neumann Stored Program Concept A serial machine Instructions and data fetched in sequence, one at a time Single shared memory Program instructions and Data Shared Data Bus Program Instructions and Data Addresses Processor Main Memory Data and Instructions 29 Fundamentals of Computer Organisation and Architecture: Computer Architecture

Stored program concept Harvard Stored Program Concept Dual Serial Machine Instructions and data fetched in sequence Separate Memory Instruction Data Separate Data Bus Instruction Data Instruction Memory Serial and Parallel Data Address

Instruction Address Processor Instruction Instructions fetched serially Data fetched serially Instructions and Data fetched in parallel 30 Fundamentals of Computer Organisation and Architecture: Computer Architecture Read/Write Data Data Memory Von Neumann versus Harvard Von Neumann architecture

Addresses Instruction and data shares the same bus Compete for resources Processor Main Memory Data and Instructions Harvard architecture No competition Instruction fetches and reading and writing of data take place in parallel Increases overall processing speed Instruction Memory 31 Data Address

Instruction Address Processor Instruction Fundamentals of Computer Organisation and Architecture: Computer Architecture Read/Write Data Data Memory Von Neumann versus Harvard Embedded system Use Harvard architecture

Special-purpose computer system Devices using embedded system Digital Cameras, Cars, Domestic appliances and many more Built into another device Performs few dedicated functions General-purpose computer (personal computer) Von Neumann Architecture Programmed and reprogrammed Perform many different tasks 32 Fundamentals of Computer Organisation and Architecture: Computer Architecture

Recently Viewed Presentations

  • Basic Principles (PIES) - Weebly

    Basic Principles (PIES) - Weebly

    Simultaneous interaction can be responses or a sharing of ideas in teams or pairs. Simultaneous Interaction. The purpose of PIES is to tell us where to look and how to restructure when things are not going well. If implemented correctly,...
  • The Paper Crane By Molly Bang This is

    The Paper Crane By Molly Bang This is

    Molly Bang This is modern fiction, not a folktale. Molly Bang tells the story in a way that sounds like a folktale, but it was not passed down from one generation to the next. serve: help others. They serve good...
  • Live United

    Live United

    Navigators - Resources and Gaps. IDOI reports - As of early January, there were nearly 700 individual certified navigators in 130 applicant organization sites.. A challenge for consumers - While there are many Navigators and events, it is hard to...
  • Integumentary System

    Integumentary System

    - cuticle-cortex-medulla. The Hair. The Cuticle. Covers the hair fiber. ... Cuticle: the overlapping skin surrounding the nail. Its purpose is to protect the matrix from invading bacteria and physical damage. Matrix: this is where the nail is made. It...
  • Crowd++: Unsupervised Speaker Count with Smartphones ACM UbiComp13

    Crowd++: Unsupervised Speaker Count with Smartphones ACM UbiComp13

    We use 3-second for basic speech unit. Chenren Xu. [email protected] Speaker features. MFCC + cosine similarity distance metric. 3-second speech segment. 30. 15. Chenren Xu. [email protected] Speaker features. Pitch + gender statistics (Hz)
  • Slide 1

    Slide 1

    Is the energy dependent technological fix of desalination the answer? Photo of a plant in Dubai. In the Western Region: Israelis, Syrians, Jordanians and Lebanese are all in dispute over shrinking water supplies. A contributory factor to the 1967 Arab-Israeli...
  • EdinburghUni

    EdinburghUni

    These efforts built the prodigious under the guidance of leading Shari'a scholars such as Sheikh Taqi Usmani, Sheikh Musam Jacobi, Dr Mohammed Algufri - it helped HSBC Amanah track and build the best possible management team and above all, service...
  • Should I Take PrEP?A Mental Models Assessment of ... - AIDS 2018

    Should I Take PrEP?A Mental Models Assessment of ... - AIDS 2018

    We asked about factors that would influence choice to take PrEP, such as: having to pay, side effects, travel far to get it/clinic visits, privacy, daily pill, partner not supportive, costs… Few inputs are hard stops (except money/travel). Ps who...