Introduction to Computer Engineering CS ECE 252 Fall 2007 Prof Mark D Hill Computer Sciences Department University of Wisconsin Madison Chapter 1 Welcome Aboard Slides based on set prepared by Gregory T Byrd North Carolina State University Copyright The McGraw Hill Companies Inc Permission required for reproduction or display Computer System Layers of Abstraction Application Program Algorithms Software Hardware Language Instruction Set Architecture and I O Interfaces Microarchitecture Circuits Devices 1 3 Copyright The McGraw Hill Companies Inc Permission required for reproduction or display Big Idea 1 Universal Computing Device All computers given enough time and memory are capable of computing exactly the same things PDA Workstation Supercomputer 1 4 Copyright The McGraw Hill Companies Inc Permission required for reproduction or display Turing Machine Mathematical model of a device that can perform any computation Alan Turing 1937 ability to read write symbols on an infinite tape state transitions based on current state and symbol Every computation can be performed by some Turing machine Turing s thesis a b Tadd a b Turing machine that adds a b Tmul ab Turing machine that multiplies 1 5 Copyright The McGraw Hill Companies Inc Permission required for reproduction or display Universal Turing Machine Turing described a Turing machine that could implement all other Turing machines inputs data plus a description of computation Turing machine Tadd Tmul a b c U c a b Universal Turing Machine U is programmable so is a computer instructions are part of the input data a computer can emulate a Universal Turing Machine and vice versa Therefore a computer is a universal computing device 1 6 Copyright The McGraw Hill Companies Inc Permission required for reproduction or display From Theory to Practice In theory computer can compute anything that s possible to compute given enough memory and time In practice solving problems involves computing under constraints time weather forecast next frame of animation cost cell phone automotive engine controller power cell phone handheld video game 1 7 Copyright The McGraw Hill Companies Inc Permission required for reproduction or display Big Idea 2 Transformations Between Layers How do we solve a problem using a computer A systematic sequence of transformations between layers of abstraction Problem Problem Software Design choose algorithms and data structures Algorithm Algorithm Programming use language to express design Program Program Instr Instr Set Set Architecture Architecture Compiling Interpreting convert language to machine instructions 1 8 Copyright The McGraw Hill Companies Inc Permission required for reproduction or display Deeper and Deeper Instr InstrSet Set Architecture Architecture Microarch Microarch Circuits Circuits Devices Devices Processor Design choose structures to implement ISA Logic Circuit Design gates and low level circuits to implement components Process Engineering Fabrication develop and manufacture lowest level components 1 9 Copyright The McGraw Hill Companies Inc Permission required for reproduction or display Descriptions of Each Level Problem Statement stated using natural language may be ambiguous imprecise Algorithm step by step procedure guaranteed to finish definiteness effective computability finiteness Program express the algorithm using a computer language high level language low level language Instruction Set Architecture ISA specifies the set of instructions the computer can perform data types addressing mode 1 10 Copyright The McGraw Hill Companies Inc Permission required for reproduction or display Descriptions of Each Level cont Microarchitecture detailed organization of a processor implementation different implementations of a single ISA Logic Circuits combine basic operations to realize microarchitecture many different ways to implement a single function e g addition Devices properties of materials manufacturability 1 11 Copyright The McGraw Hill Companies Inc Permission required for reproduction or display Many Choices at Each Level Solve a system of equations Red black SOR FORTRAN Sun SPARC Pentium II C C Intel x86 Pentium III Ripple carry adder CMOS Jacobi iteration Gaussian elimination Bipolar Java Compaq Alpha AMD Athlon Multigrid Tradeoffs cost performance power etc Carry lookahead adder GaAs 1 12 Copyright The McGraw Hill Companies Inc Permission required for reproduction or display What s Next Bits and Bytes How do we represent information using electrical signals Digital Logic How do we build circuits to process information Processor and Instruction Set How do we build a processor out of logic elements What operations instructions will we implement Assembly Language Programming How do we use processor instructions to implement algorithms How do we write modular reusable code subroutines I O Traps and Interrupts How does processor communicate with outside world 1 13