EEL 4713/EEL 5764 Computer Architecture Spring Semester 2004 Instructor: Dr. Shonda Walker Required Textbook: Computer Organization & Design, by Patterson and Hennessy, 2 nd Ed.

EEL 4713/EEL 5764 S. Walker2 Computers have led to the information revolution or technological movement. Technologies used in computers (Fig in text): Computer technology (in terms of memory capacity and processor speed) is a rapidly changing field quadrupling every 3 years! (aka The DRAM Growth Rule  4 times every 3 years). Chapter 1 Computer Abstractions and Technology Vacuum Tubes (1951) Transistor (1965) IC (1975) VLSI (1995)

EEL 4713/EEL 5764 S. Walker3 Innovative computer systems have led to the development of applications that until recently were economically infeasible: Automatic Teller Machines (ATMs) Laptop Computers The Internet Computer performance has been a primary concern for computer architects and programmers (memory versus speed). Chapter 1 Computer Abstractions and Technology

EEL 4713/EEL 5764 S. Walker4 Major goals of this text: 1.To understand how computers work by understanding machine language; 2. To understand the internal organization of computers; 3. To identify and evaluate performance metrics for a computers and their programs; Chapter 1 Computer Abstractions and Technology

5 What is a computer? Inside a computer (The Big Picture) Chapter 1 Computer Abstractions and Technology Control Datapath Input Output Memory Five Classic Components of a Computer ( based on the Von Neumann model) Memory where programs are kept when they are running; also contains data needed by programs Control one of two components of processor that tells memory, datapath, and I/O devices what to do Datapath one of two components of processor that performs arithmetic operations Input Devices devices that supply input to the computer such as the keyboard and the mouse Output Devices devices, such as printer and monitor, that convey the result of a computation to the user

EEL 4713/EEL 5764 S. Walker6 Computers communicate using machine language which is a binary representation of electrical signals (1 and 0). Binary digits are known as bits. Since computers only follow commands, we say the individual commands are called instructions. For example: is an instruction that tells a computer to add two numbers (more in chapter 3). Chapter 1 Computer Abstractions and Technology

EEL 4713/EEL 5764 S. Walker7 Bits are used to represent both instructions and data. Initially only binary numbers are used to design and program computers, however this became tedious. Hence, the development of assembly language and high-level programming languages. The notion of low-level and high-level programming is a common approach to hardware and software system design. A system that consists of hierarchical layers with each lower layer hiding the details from the layer above it is known as abstraction. Chapter 1 Computer Abstractions and Technology

EEL 4713/EEL 5764 S. Walker8 Chapter 1 Computer Abstractions and Technology Levels or layers of Abstraction can be though of as the highest “user” level to the lowest level (transistor level). Separability is the key to effective computer abstraction. For example, if you run Microsoft Word or some other word processing program, you don’t need to know anything about the inner-workings of its programming. Exploiting separability supports the development of upwardly-compatible machines (allows a user to upgrade to a faster, more capable machine without rewriting the software the runs on the less capable machine)

EEL 4713/EEL 5764 S. Walker9 Chapter 1 General Levels of Abstraction User Level – Applications Programs High-level Languages Assembly Language/Machine Code Mircoprogrammed/Hardwired Control Functional Units (memory, ALU, etc.) Logic Gates Transistors and Wires Highest Level Lowest Level

EEL 4713/EEL 5764 S. Walker10 Instruction Set Architecture The programmer’s view of computer technology deals primarily with the instruction set architecture and functional units of the machine. The computer architect views the system at all levels. He/She focuses on parameters that affect the design of a computer emphasizing performance requirements and cost constraints. Chapter 1 Computer Abstractions and Technology Our focus

EEL 4713/EEL 5764 S. Walker11 Chapter 1 Computer Abstractions and Technology High-level Language (in C) Assembly Language Program Binary Machine Language Compiler Assembler A + B add A, B (High-level Instruction) Example (Assembly Language Statement) (Binary Instruction)

EEL 4713/EEL 5764 S. Walker12 Chapter 1 Computer Abstractions and Technology The remainder of the semester: –Chapter 2: Performance and Cost Analysis –Chapter 3: Instruction Set Architecture –Chapter 4: Computer Arithmetic and building an ALU –Chapter 5: Controller and Datapath Systems –Chapter 6: Pipelining –Chapter 7: Memory Hierarchy –Chapter 8: Input/Output Systems –Chapter 9: Multiprocessors

EEL 4713/EEL 5764 S. Walker13 Chapter 1 Take-home Quiz #1 Briefly (no more than 1 page) discuss the history of computers include a description of the Von Neumann architecture and its main components. Due next class period: Monday January 12, 2004