COE 224 - Computer Architecture

• Course is COE 224- Computer Organization and Architecture (1)
• Course is focused on the the hardware/software interface.
• The textbook used is in its 5th Edition

Course Content

• Overview of computer architecture and organization
• Assemblers and Linkers
• Instruction Set Architecture
• Processor systems design
• Overview of Pipelining
• Memory Technologies and Hierarchies
• Interfacing and Communication with Input/Output devices

Laboratory Content

• Programming in assembly language
• The processor which includes datapath and control unit
• Input/Output Units
• Arithmetic-Logic Unit

Course References

• Patterson and Hennessy wrote "Computer Organization and Design: The Hardware/Software Interface", 5th Edition, Morgan Kaufmann (MK), 2013.
• C. Hamacher, Z. Vranesic, S. Zaky, and N. Manjikian wrote "Computer Organization and Embedded Systems", 6th Edition, McGraw-Hill, 2011.
• J. Carpinelli wrote “Computer Systems Organization and Architecture", 2nd Edition, Addison Wesley, 2006.

Course Plan

• MidTerm 1: 15 Marks
• MidTerm 2: 15 Marks
• Assignments/Quizzes: 10 Marks
• Lab: 20 Marks
• Final Exam: 40 Marks

Chapter 1 - Computer Organization and Architecture Overview

• Progress relies on computer technology and is underpinned by Moore's Law
• Computers are pervasive, making novel applications feasible
• Applications that were made possible include computers in automobiles, cell phones, human genome project, World Wide Web and search engines

Classes of Computers

• Personal Computers: General purpose with variety of software, subject to cost/performance tradeoff
• Server Computers: Network based with high capacity, performance, and reliability, ranging from small servers to building sized
• Supercomputers: For high-end scientific and engineering calculations, represent a small fraction of the overall computer market, have the highest capability
• Embedded Computers: Hidden as components of systems and have stringent power/performance/cost constraints

The PostPC Era

• Personal Mobile Device (PMD) is battery operated, connects to the Internet, and costs hundreds of dollars like smartphones, tablets, electronic glasses
• Cloud computing uses Warehouse Scale Computers (WSC) and Software as a Service (SaaS) with a portion of software run on a PMD and a portion run in the Cloud
• Large cloud computing examples include things like Amazon and Google

Course Learning Outcomes

• How programs are translated into the machine language and how the hardware executes them
• Hardware/software interface
• What determines program performance
• How performance can be improved
• How hardware designers improve performance
• Parallel processing.

Understanding System Performance

• Algorithm determines number of operations executed
• The programming language, compiler, and architecture determines number of machine instructions executed per operation
• The processor and memory system determines how fast instructions are executed
• I/O system including OS determines how fast I/O operations are executed

Eight Great Ideas in Computer Architecture

• Design for Moore's Law - integrated circuit resources double every 18-24 months
• Use Abstraction to simplify design with hardware and software, using different levels of representation
• Make the common case fast
• Performance via parallelism, offering designs that get more performance by performing operations in parallel
• Performance via pipelining; is a way of speeding up execution of instructions by overlapping execution of multiple instructions
• Performance via prediction with guessing and starting to work rather than wait, assuming that the mechanism to recover from a misprediction is not too expensive
• Hierarchy of memories and what parts are cheapest to implement at memory storage points
• Dependability via redundancy

Below Your Program

• Application software is written in high-level language
• System software includes a compiler to translates high level language code into machine code
• Operating System is service code that handles input/output, managing memory and storage and scheduling tasks & sharing resources
• Hardware consists of a processor, memory and I/O controllers

Levels of Program Code

• High-level language is closer to the problem domain and also provides better productivity and portability
• Assembly language that is a textual representation of instructions
• Hardware representation in binary digits (bits) with Encoded instructions and data

Components of a Computer

• It consist of same components for desktop, server, and embedded computers with Input/output devices
• Input/output includes user-interface devices like displays, keyboard, mouse, storage devices like hard disks, or CD/DVD flash drives
• Also contains network adapters for communicating with other computers

Touchscreen

• A PostPC device that supersedes keyboards and mouses
• Resistive and Capacitive types
• Most tablets and smartphones use capacitive touchscreens, because a Capacitive allows multiple touches simultaneously

Memory systems

• Has Dynamic Random Access Memory (DRAM) choice for main memory that is volatile, fast, and relatively small
• DRAM capacity doubles every 2 years since 1996
• Static Random Access Memory (SRAM), is the choice for cache memory
• SRAM is much faster than DRAM but less dense and more costly
• Magnetic disks are the choice for secondary memory that are non-volatile, slower, and relatively large
• Magnetic capacity has doubled every 1 year since 1997
• Solid state (Flash) memory is the choice for embedded computers and is non-volatile
• Optical disk (CDROM, DVD)

Inside the Processor (CPU)

• Datapath performs operations on data
• Control: sequences datapath, memory, and more
• Cache memory that is Small, fast SRAM memory for immediate access to relevant data

Abstractions

• This helps deal with complexity by hiding the lower-level details
• Instruction Set Architecture (ISA) is hardware/software interface
• Application binary interface is ISA plus system software interface
• Implementation is the details underlying and interface

Networks

• It is based on Communication, resource sharing, nonlocal access
• Local area network (LAN) uses Ethernet
• Wide area network (WAN) uses the Internet
• Wireless network that uses WiFi and Bluetooth

Technology Trends

• Electronics technology continues to evolve, increasing capacity and performance and reducing costs
• DRAM capacity has been increasing and reducing in cost

Semiconductor Technology

• Silicon is a semiconductor, for this special chemical process, it is possible to add materials to silicon that allow tiny areas to transform into one of the Conductor, Insulator, and Switch devices

Manufacturing ICs

• Steps include Using Silicon ingot -> Slicer -> Blank wafers -> 20 to 40 processing steps -> Tested dies -> Dicer -> Tested wafer -> Wafer tester -> Packaged dies -> Tested packages dies -> Part tester -> Ship to customers
• Yield is the proportion of working dies per wafer

Intel Core i7 Wafer

• Consists of a 300mm wafer, 280 chips, 32nm technology with each chip is 20.7 x 10.5 mm

Parts of a computer System

• Computer Architecture is the sum of Instruction Set Architecture + Computer Organization
• The Instruction Set Architecture (ISA) WHAT the computer does (logical view)
• Computer Organization - HOW the ISA is implemented (physical view)

Instruction Set Architecture

• This is a very important abstraction that acts as an interface between hardware and low-level software
• isa Standardize's instructions, and machine language bit patterns, etc.
• It enables different implementations of the same architecture
• One of the disadvantages is that this sometimes prevent additions of new innovations
• Modern instruction set architectures include 80x86/Pentium/K6, PowerPC, DEC Alpha, MIPS, SPARC, HP.

Concluding Remarks

• Cost/performance is improving, hierarchical layers of abstraction is in both hardware and software
• Instruction set architecture is the hardware/software interface.