Introduction to Computing Systems: From Bits and Gates to C and Beyond 2 nd Edition

Transcription

1 Lecture Goals Itroductio to Computig Systems: From Bits ad Gates to C ad Beyod 2 d Editio Yale N. Patt Sajay J. Patel Origial slides from Gregory Byrd, North Carolia State Uiversity Modified slides by Chris Wilcox, Adres Caldero J., Sajay Rajopadhye, CSU Review course logistics Assigmets Policies Orgaizatio Gradig Criteria Itroduce key cocepts Role of Abstractio Software versus Hardware Uiversal Computig Devices Layered Model of Computig 1 2 Logistics Assigmets Lectures: See syllabus Staff: See syllabus Recitatios: See syllabus Help desks: See syllabus Office hours: See syllabus Materials o the website: Piazza: access through Cavas Assigmets are posted o website: Weekly assigmets (mostly) alterate betwee writte ad programmig assigmets. Homework assigmets: submissio mode ad deadlie varies. Programmig assigmets are submitted i electroic form Su. at 10pm. Late submissio varies depedig o the difficulty of the assigmet. Regradig: through Piazza (see syllabus)

2 Policies Gradig Criteria Assigmets (35%) Recitatios (10%) Peer Istructio (5%) Two Midterm Exams (15% each) Fial Exam (20%) You must ear a passig grade (60% or higher) o each part assigmets ad exams i order to pass the class Late Policy O-time = full poits, late submissio= 20% pealty Academic Itegrity Do your ow work Be smart about Iteret resources Orgaizatio 1/3 computer hardware: umbers ad bits, trasistors, gates, digital logic, state machies, vo Neuma model, istructio sets, LC-3 architecture 1/3 assembly code: istructio formats, brachig ad cotrol, LC-3 programmig, subrouties, memory model (stack) 1/3 C programmig: data types, laguage sytax, variables ad operators, cotrol structures, fuctios, poiters ad arrays, memory model, recursio, I/O, data structures 5 6 Gradig Criteria How to be successful i this class: 1) Atted all classes ad recitatios, ifo will preseted that you ca t get aywhere else. 2) Do all the homework assigmets, ask questios (early! (but ot too early)) if you ru ito trouble. 3) Take advatage of lab sessios where help is available from istructors. 4) Read the textbook, work through the ed of chapter problems. Chapter 1 Welcome Aboard 7 2

3 Itroductio to the World of Computig Two Recurrig Themes Computer: electroic geius? NO! Electroic idiot! Does exactly what we tell it to, othig more. Goal of the course: You will be able to write programs i C You will uderstad how a computer works (what s goig o uder the hood). Textbook Approach: From the bottom up (we will use mostly a top-dow approach). Bits Trasistors Gates Logic Processor Istructios Assembly Code C Programmig Abstractio Productivity ehacer do t eed to worry about details Ca drive a car without kowig how the iteral combustio egie works. util somethig goes wrog! Where s the dipstick? What s a spark plug? Importat to uderstad the compoets ad how they work together Two Recurrig Themes Hardware vs. Software It s ot either/or both are compoets of a computer system that cooperate. Eve if you specialize i oe, you should uderstad capabilities ad limitatios of both. The best programmers uderstad the computer systems which ru their programs. Computers are a etire ecosystem with multiple levels of abstractio. Big Idea #1: Uiversal Computig Devices All computers, give eough time ad memory, are capable of computig exactly the same thigs. PDA = = Workstatio Supercomputer

4 a,b Turig Machie Mathematical model of a device that ca perform ay computatio Ala Turig (1937) ability to read/write symbols o a ifiite tape state trasitios, based o curret state ad symbol Every computatio ca be performed by some Turig machie. (Turig s thesis) T add Turig machie that adds a+b For more ifo about Turig machies, see a,b T mul ab Turig machie that multiplies For more about Ala Turig, see 13 Uiversal Turig Machie A machie that ca implemet all Turig machies this is also a Turig machie! iputs: data, descriptio of computatio (other TMs) T add, T mul a,b,c U c(a+b) Uiversal Turig Machie Uiversal machie is programmable so is a computer! istructios are part of the iput data a computer ca emulate a Uiversal Turig Machie A computer is a uiversal computig device. 14 From Theory to Practice I theory, computer ca compute aythig that ca possibly be computed give eough memory ad time I practice, solvig problems ivolves computig uder costraits. time weather forecast, ext frame of aimatio,... cost cell phoe, automotive egie cotroller,... Power/eergy cell phoe, hadheld video game,... Big Idea #2: Trasformatios Betwee Layers Problems Algorithms Laguage Istructio Set Architecture Microarchitecture Circuits Devices

5 How do we solve a problem usig a computer? A systematic sequece of trasformatios betwee layers of abstractio. Problem Algorithm Program Istr Set Architecture Software Desig: choose algorithms ad data structures Programmig: use laguage to express desig Compilig/Iterpretig: covert laguage to machie istructios 17 Istr Set Architecture Microarch Circuits Devices Deeper ad Deeper Processor Desig: choose structures to implemet ISA Logic/Circuit Desig: gates ad low-level circuits to implemet compoets Process Egieerig & Fabricatio: develop ad maufacture lowest-level compoets 18 Descriptios of Each Level Problem Statemet stated usig "atural laguage" may be ambiguous, imprecise Algorithm step-by-step procedure, guarateed to fiish defiiteess, effective computability, fiiteess Program express the algorithm usig a computer laguage high-level laguage, low-level laguage Istructio Set Architecture (ISA) specifies the set of istructios the computer ca perform data types, addressig mode Descriptios of Each Level (cot.) Microarchitecture detailed orgaizatio of a processor implemetatio differet implemetatios of a sigle ISA Logic Circuits combie basic operatios to realize microarchitecture may differet ways to implemet a sigle fuctio (e.g., additio) Devices properties of materials, maufacturability

6 Red-black SOR May Choices at Each Level Solve a system of equatios Gaussia elimiatio Jacobi iteratio FORTRAN C C++ Java PowerPC Itel x86 Atmel AVR Cetrio Petium 4 Xeo Ripple-carry adder Carry-lookahead adder CMOS Bipolar GaAs Multigrid Tradeoffs: cost performace power (etc.) 21 Book Outlie Bits ad Bytes How do we represet iformatio usig electrical sigals? Digital Logic How do we build circuits to process iformatio? Processor ad Istructio Set How do we build a processor out of logic elemets? What operatios (istructios) will we implemet? Assembly Laguage Programmig How do we use processor istructios to implemet algorithms? How do we write modular, reusable code? (subrouties) I/O, Traps, ad Iterrupts How does processor commuicate with outside world? C Programmig How do we write programs i C? 22 Course Outlie First, C programmig (plus Bits/Bytes/Numbers) Sice you already have two semesters of Java Lear the C memory model How fuctio parameters are passed (activatio records, stack) Assembly Laguage Programmig How do we use processor istructios (three address istructios) to implemet C programs (traslatio)? How do we implemet modular, reusable code? (subrouties) How structured programs are broke dow ito straight-lie code with (coditioal) braches? Istructio set processor Istructios ad Data (the vo Neuma model)? Digital circuits Trasistors ad Gates, Memory ad State machies How the processor is built out of these (Register Trasfer Notatio) I/O, Traps, ad Iterrupts How does processor commuicate with outside world? 23 6