CSI 212 Chapter 1 Slides, Spring 2012

Assembly Language for Intel-Based Assembly Language for Intel-Based Computers, 5 Computers, 5th th Edition Edition Chapter 1: Basic Concepts (c) Pearson Education, 2006-2007. All rights reserved. You may modify and copy this slide show for your personal use, or for use in the classroom, as long as this copyright statement, the author's name, and the title are not changed. Slides prepared by the author Revision date: June 3, 2006 Kip Irvine Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 2 Chapter Overview Chapter Overview • Welcome to Assembly Language • Virtual Machine Concept • Data Representation • Boolean Operations Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 3 Welcome to Assembly Language Welcome to Assembly Language • Some Good Questions to Ask • Assembly Language Applications Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 4 Questions to Ask Questions to Ask • Why am I learning Assembly Language? • What background should I have? • What is an assembler? • What hardware/software do I need? • What types of programs will I create? • What do I get with this book? • What will I learn? Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 5 Welcome to Assembly Language Welcome to Assembly Language (cont) (cont) • How does assembly language (AL) relate to machine language? • How do C++ and Java relate to AL? • Is AL portable? • Why learn AL? Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 6 Assembly Language Applications Assembly Language Applications • Some representative types of applications: • Business application for single platform • Hardware device driver • Business application for multiple platforms • Embedded systems & computer games (see next panel) Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 7 Comparing ASM to High-Level Languages Comparing ASM to High-Level Languages Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 8 What's Next What's Next • Welcome to Assembly Language • Virtual Machine Concept • Data Representation • Boolean Operations Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 9 Virtual Machine Concept Virtual Machine Concept • Virtual Machines • Specific Machine Levels Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 10 Virtual Machines Virtual Machines • Tanenbaum: Virtual machine concept • Programming Language analogy: • Each computer has a native machine language (language L0) that runs directly on its hardware • A more human-friendly language is usually constructed above machine language, called Language L1 • Programs written in L1 can run two different ways: • Interpretation – L0 program interprets and executes L1 instructions one by one • Translation – L1 program is completely translated into an L0 program, which then runs on the computer hardware Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 11 Translating Languages Translating Languages English: Display the sum of A times B plus C. C++: cout << (A * B + C); Assembly Language: mov eax,A mul B add eax,C call WriteInt Intel Machine Language: A1 00000000 F7 25 00000004 03 05 00000008 E8 00500000 Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 12 Specific Machine Levels Specific Machine Levels (descriptions of individual levels follow . . . ) Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 13 High-Level Language High-Level Language • Level 5 • Application-oriented languages • C++, Java, Pascal, Visual Basic . . . • Programs compile into assembly language (Level 4) Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 14 Assembly Language Assembly Language • Level 4 • Instruction mnemonics that have a one-to- one correspondence to machine language • Calls functions written at the operating system level (Level 3) • Programs are translated into machine language (Level 2) Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 15 Operating System Operating System • Level 3 • Provides services to Level 4 programs • Translated and run at the instruction set architecture level (Level 2) Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 16 Instruction Set Architecture Instruction Set Architecture • Level 2 • Also known as conventional machine language • Executed by Level 1 (microarchitecture) program Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 17 Microarchitecture Microarchitecture • Level 1 • Interprets conventional machine instructions (Level 2) • Executed by digital hardware (Level 0) Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 18 Digital Logic Digital Logic • Level 0 • CPU, constructed from digital logic gates • System bus • Memory • Implemented using bipolar transistors next: Data Representation Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 19 What's Next What's Next • Welcome to Assembly Language • Virtual Machine Concept • Data Representation • Boolean Operations Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 20 Data Representation Data Representation • Binary Numbers • Translating between binary and decimal • Binary Addition • Integer Storage Sizes • Hexadecimal Integers • Translating between decimal and hexadecimal • Hexadecimal subtraction • Signed Integers • Binary subtraction • Character Storage Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 21 Binary Numbers Binary Numbers • Digits are 1 and 0 • 1 = true • 0 = false • MSB – most significant bit • LSB – least significant bit • Bit numbering: 0 15 1 0 1 1 0 0 1 0 1 0 0 1 1 1 0 0 MSB LSB Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 22 Binary Numbers Binary Numbers • Each digit (bit) is either 1 or 0 • Each bit represents a power of 2: Every binary number is a sum of powers of 2 Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 23 Translating Binary to Decimal Translating Binary to Decimal Weighted positional notation shows how to calculate the decimal value of each binary bit: dec = (Dn-1 2n-1)  (Dn-2  2n-2)  ...  (D1  21)  (D0  20) D = binary digit binary 00001001 = decimal 9: (1  23) + (1  20) = 9 Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 24 Translating Unsigned Decimal to Binary Translating Unsigned Decimal to Binary • Repeatedly divide the decimal integer by 2. Each remainder is a binary digit in the translated value: 37 = 100101 Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 25 Binary Addition Binary Addition • Starting with the LSB, add each pair of digits, include the carry if present. Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 26 Integer Storage Sizes Integer Storage Sizes What is the largest unsigned integer that may be stored in 20 bits? Standard sizes: Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 27 Hexadecimal Integers Hexadecimal Integers Binary values are represented in hexadecimal. Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 28 Translating Binary to Hexadecimal Translating Binary to Hexadecimal • Each hexadecimal digit corresponds to 4 binary bits. • Example: Translate the binary integer 000101101010011110010100 to hexadecimal: Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 29 Converting Hexadecimal to Decimal Converting Hexadecimal to Decimal • Multiply each digit by its corresponding power of 16: dec = (D3  163) + (D2  162) + (D1  161) + (D0  160) • Hex 1234 equals (1  163) + (2  162) + (3  161) + (4  160), or decimal 4,660. • Hex 3BA4 equals (3  163) + (11 * 162) + (10  161) + (4  160), or decimal 15,268. Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 30 Powers of 16 Powers of 16 Used when calculating hexadecimal values up to 8 digits long: Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 31 Converting Decimal to Hexadecimal Converting Decimal to Hexadecimal decimal 422 = 1A6 hexadecimal Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 32 Hexadecimal Addition Hexadecimal Addition • Divide the sum of two digits by the number base (16). The quotient becomes the carry value, and the remainder is the sum digit. 36 28 28 6A 42 45 58 4B 78 6D 80 B5 1 1 21 / 16 = 1, rem 5 Important skill: Programmers frequently add and subtract the addresses of variables and instructions. Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 33 Hexadecimal Subtraction Hexadecimal Subtraction • When a borrow is required from the digit to the left, add 16 (decimal) to the current digit's value: C6 75 A2 47 24 2E 1 16 + 5 = 21 Practice: The address of var1 is 00400020. The address of the next variable after var1 is 0040006A. How many bytes are used by var1? Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 34 Signed Integers Signed Integers The highest bit indicates the sign. 1 = negative, 0 = positive If the highest digit of a hexadecimal integer is > 7, the value is negative. Examples: 8A, C5, A2, 9D Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 35 Forming the Two's Complement Forming the Two's Complement • Negative numbers are stored in two's complement notation • Represents the additive Inverse Note that 00000001 + 11111111 = 00000000 Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 36 Binary Subtraction Binary Subtraction • When subtracting A – B, convert B to its two's complement • Add A to (–B) 0 0 0 0 1 1 0 0 0 0 0 0 1 1 0 0 – 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 1 0 0 0 0 1 0 0 1 Practice: Subtract 0101 from 1001. Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 37 Learn How To Do the Following: Learn How To Do the Following: • Form the two's complement of a hexadecimal integer • Convert signed binary to decimal • Convert signed decimal to binary • Convert signed decimal to hexadecimal • Convert signed hexadecimal to decimal Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 38 Ranges of Signed Integers Ranges of Signed Integers The highest bit is reserved for the sign. This limits the range: Practice: What is the largest positive value that may be stored in 20 bits? Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 39 Character Storage Character Storage • Character sets • Standard ASCII (0 – 127) • Extended ASCII (0 – 255) • ANSI (0 – 255) • Unicode (0 – 65,535) • Null-terminated String • Array of characters followed by a null byte • Using the ASCII table • back inside cover of book Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 40 Numeric Data Representation Numeric Data Representation • pure binary • can be calculated directly • ASCII binary • string of digits: "01010101" • ASCII decimal • string of digits: "65" • ASCII hexadecimal • string of digits: "9C" next: Boolean Operations Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 41 What's Next What's Next • Welcome to Assembly Language • Virtual Machine Concept • Data Representation • Boolean Operations Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 42 Boolean Operations Boolean Operations • NOT • AND • OR • Operator Precedence • Truth Tables Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 43 Boolean Algebra Boolean Algebra • Based on symbolic logic, designed by George Boole • Boolean expressions created from: • NOT, AND, OR Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 44 NOT NOT • Inverts (reverses) a boolean value • Truth table for Boolean NOT operator: NOT Digital gate diagram for NOT: Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 45 AND AND • Truth table for Boolean AND operator: AND Digital gate diagram for AND: Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 46 OR OR • Truth table for Boolean OR operator: OR Digital gate diagram for OR: Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 47 Operator Precedence Operator Precedence • Examples showing the order of operations: Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 48 Truth Tables Truth Tables (1 of 3) (1 of 3) • A Boolean function has one or more Boolean inputs, and returns a single Boolean output. • A truth table shows all the inputs and outputs of a Boolean function Example: X  Y Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 49 Truth Tables Truth Tables (2 of 3) (2 of 3) • Example: X  Y Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 50 Truth Tables Truth Tables (3 of 3) (3 of 3) • Example: (Y  S)  (X  S) Two-input multiplexer Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 51 Summary Summary • Assembly language helps you learn how software is constructed at the lowest levels • Assembly language has a one-to-one relationship with machine language • Each layer in a computer's architecture is an abstraction of a machine • layers can be hardware or software • Boolean expressions are essential to the design of computer hardware and software Irvine, Kip R. Assembly Language for Intel-Based Computers 5/e, 2007. Web site Examples 52 54 68 65 20 45 6E 64 54 68 65 20 45 6E 64 What do these numbers represent?