INTRODUCTION TO

Compiled by: Seble N. What is ?

2

coined the term in 1971

 usually made of millions of microscopic array of electronic circuits and electronic components (resistors, capacitors, inductors…) are diffused or implanted to surface of small silicon chip

 its basic function is to take input, it and then provide appropriate output

 Examples  , AMD , a PowerPC, a Sun-SPARC or any of the many other brands and types of microprocessors Function of microprocessors

3

 A microprocessor performs three basic steps:

 First, it fetches an instruction from memory,

 Second, it uses decoding circuitry to determine what the instruction means (i.e., identify the operations and the devices involved in it) and

 Third, it executes the instruction

Components of microprocessor

4  ALU (Arithmetic/Logic Unit)

 performs all arithmetic and logic operations

 Control Unit

 holds the circuitry that controls the process of executing, decoding and fetching program instructions  it controls the flow of data between the μ-processor and memory & peripherals  it controls the operation of ALU, I/O devices, and memory unit

 Registers

 A register is a very small & very fast memory that is built into the CPU in order to store the current data and instructions which are being executed by the CPU Modes of Processing

5

 One program at a time

 Can run more than one program concurrently and protect them from each other

 Virtual Mode

 The processor can swap portion of the memory to the hard disk; in this way programs running concurrently will have more space to operate

Characteristics of microprocessors

6

 Instruction set  the set of instructions that a microprocessor can understand or execute

 Word length  refers to the number of bits a processor can process at a time  Eg. a 4-bit processor means the ALU can perform a 4-bit data operation at a time  the longer the word length is the more powerful the processor is and can process data at a faster speed as compared to processor with shorter word length Characteristics of microprocessors

7

 Speed

 measured in HZ = 1cycle/second

 Some processors may complete a single instruction per cycle, or may take one or more cycles

 a 2 GHZ CPU may compute 2 billion , if it is able to complete a single instruction in a single cycle

 but if it takes 2 cycles to complete a single instruction then it is only able to compute 1 billion instructions per second

 Cache Size

 The size of the cache memory Characteristics of microprocessors …

8

 Size of registers

 refers to the number of bits a microprocessor’s register can hold at a time

 the size of addressable memory is often determined by the width of registers

 Data width

 Refers to the number of bits a data bus can carry at a time Classes of microprocessors

9

 Complex instruction set (CISC)

 Reduced instruction set computer (RISC)

 Application Specific (ASIC)

 Digital Signal Multiprocessors (DSP)

 Superscalar Microprocessors Classes of microprocessors …

10

 Complex instruction set computer (CISC)

 is more complex and has the ability to perform complex commands

 it allows the user to apply 1 instruction as an alternative to many simple instructions

 can perform complex functions with one instruction

 Ex: Intel’s Pentium and chips

Classes of microprocessors …

11

 Reduced instruction set computer (RISC)

 are made according to the function in which the microprocessor can carry out small things in specific command

 In this way these processors completes more commands at a faster rate

 is simpler, smaller and faster

 usually need multiple instructions

 Ex: PowerPC and ARM's Cortex chips Evolution of Microprocessors

12

 Computing technologies based on vacuum tubes and

 In 1959, Fair child semiconductors invented the first integrated circuit

 In 1968, Gordan Moore, & Andrew Grove founded Intel(Integrated Electronics)

 In 1971, the first microprocessor, was released

 In 1972, Intel released the first 8-bit microprocessor

 In 1976, MOS technologies introduced the 6502 an 8-bit processor, used in Apple I and II

 In 1981, the first PC was created by IBM using intel’s 8088 microprocessor

 Several companies like Intel, AMD, IBM, ARM, PowerPC, Motorola… make general purpose processors that are designed for personal , laptops, mobile devices and large central servers Evolution of microprocessors

13

 Intel

 is generally regarded as the company that sets the benchmark for others to follow

 From the earlier Pentium and Centrino microprocessors to the Core 2, Core i series

 Atom chips for mobiles

 The high-end and processors for server applications

 Over 90% of laptops use Intel microprocessors  HP, Dell, Apple, Samsung, Sony, …

Top CPU manufacturers

14

 Intel  AMD  Qualcomm  Mediatek  NVIDIA  IBM  Samsung  Motorola  Hewlett-Packard (hp)  Dell  Acer  … Intel microprocessors

15

 Intel 4004   Intel 80386  Intel 80486  Pentium  Pentium II and III  Dual Core/ Core  Core i3, i5, i7 Intel microprocessors … 4-bits processors 16

 Intel 4004

 1971- the first commercially available processor as well as the first complete CPU on a single chip

 a 4-bit processor: able to operate on 4 bits of data at a time

 4-bit data bus

 had 2,300 transistors

 clock speed of 108KHZ

 640 addressable memory

 was designed for use in but also used  In traffic light controller, Blood analyzers, and even in the NASA pioneer 10 deep space probe Intel microprocessors … 8-bits processors 17

 Intel 8008

 first 8-bit microprocessor

 200KHz clock speed and 3,500 transistors,

 had 6 , 8-bit registers

 8-bit data bus

 can address up to 16KB

 Intel 8080

 1974 with 4,500 transistors with up to 2-3MHz

 can address up to 64KB

 became famous for being used in the as well as in Boeing's AGM- 86 cruise missile

 Intel 8085

 was popular as an embedded controller

 ran at 5MHZ and contained 6500 transistors Intel microprocessors … 16-bits processors 18  Intel 8086

 1978, first family microprocessor

 16-bit: all registers, internal and external buses

 Used 20-bit addressing

 Can address 1 million bytes of internal memory

 29,000 transistors, 5MHz initially

 Intel 8088

 was identical to the 8086 with the exception of its 8-bit internal bus

 The IBM 5150, the first IBM PC, came with the 8088 Intel microprocessors … 16-bits processors 19

 Intel 80286

 can operate on real and protected mode

 134,000 transistors, 6M-8MHz initially

 runs faster than the preceding processors

 can address up to 16 million bytes of internal memory

 was popular in IBM-PC AT and AT PC clones

Intel microprocessors … 32-bits processors 20

 Intel 80386

 the first 32-bit microprocessor

 32 bit registers & data bus

 can operate on protected mode and supports virtual mode

 275,000 transistors

 12MHz initially, later 33MHz

 Andy Grove decided to single-source producing 386 to AMD  Later changed in 1991 by AMD Intel microprocessors … 32-bits processors 22

 Pentium (Pentium I)

 32 bit registers

 64 bit data bus

 Has a high speed cache memory

 It can execute more than one instruction per clock cycle

 Pentium II and III

 Have a dual independent bus that provides separate path to the system cache and memory

 On-die L2 cache

Intel microprocessors … 64-bits processors 23

 New instruction set, not at all related to x86.

 Itanium  Released May 29, 2001  733 MHz to 800 MHz  2MB cache

 Itanium 2  Released July 2002  900 MHz – 1.6 GHz

Intel microprocessors … 64-bits processors 24

2  x86-64 microprocessor  Two cores on one die  Number of transistors: 291 million  64 KB of L1 cache per core  1.86-3.00 GHz

 Intel core i series  Intel core i3, i5, i7

Intel microprocessors …

25 What is an x86 architecture?

26

 x86 is a family of backward compatible instruction set architectures based on the Intel 8086 CPU and its Intel 8088 variant

 the term "x86" came into being because the names of several successors to Intel's 8086 processor end in "86", including the 80186, 80286, 80386 and 80486 processors

 all newer processors using Intel's x86 instruction set are still referred to as x86, , or i686 compatible (which means they all use extensions of the original 8086 instruction set) Intel 8086

27

 1978, first x86 family microprocessor

 16-bit: all registers, internal and external buses

 a CISC processor

 can address 1 million bytes of internal memory

 used 20-bit addressing

 to date has been maintained

8086 Microprocessor Architecture

28

 The Basic Architecture of the Intel 8086

 The processor is partitioned into two logical units

 Execution Unit (EU)

 Bus Interface Unit(BIU)

 Why partition is needed?

 Because the processor runs considerably faster than memory

Architecture of 8086

29

Execution Unit

30

 takes care of the processing including arithmetic and logic operations

 its role is to execute instructions

 Contains

 ALU,

 Control Unit and

 Registers

Bus Interface Unit (BIU)

31

 Its role is to deliver instructions and data to the EU

 Function

 to manage the bus control unit, segment registers and instruction queue

 to provide access to instructions from memory and place them in an instruction queue, which varies in size depending on the processor

 This feature enables the BIU to look ahead and prefetch instructions so that there is always a queue of instructions ready to execute Internal Memory of 8086

32

 Memory consists of cells organized in 8-bit groups

 Bytes in memory are numbered consecutively, beginning with 00

 8086

 was able to address 1MB of memory

 has 20bits wide

Intel 8086- Memory

33

 RAM

 From the 1MB of memory, the first 640K is base RAM

 is used for temporary program storage

 ROM

 The 8086 Basic Input/Output System (BIOS) begins at address 768K and handles  I/O devices, such as a hard disk controller

 ROM beginning at 960K controls the computer’s basic functions  Power-On Self-Test, dot patterns for graphics, and the disk self-

Memory Segments

34

is the division of computer's primary memory into segments or sections

 Segments are special areas defined in a program for containing the code, the data, and what is known as the stack

 A segment begins on a paragraph boundary, that is, at a location evenly divisible by 16, or hex 10.

Memory Segments …

35  In real mode, the three main segments are code, data, and stack

:  Contains the machine instructions to be executed  The first instruction is at the start of this segment, and the links to that location to begin program execution  :  Contains a program’s defined data, constants, and work areas  Stack Segment:  Contains any data and addresses that the program needs to save temporarily for use on

 A program may contain one or more segments, which may vary in size, and can be defined in any sequence 8086/8088 Registers

36

 The registers are categorized into two sets:

 Data registers

 are for calculations

 Address registers

 used to store memory addresses that point to locations in memory where data will be retrieved or stored

8086/8088 Data Registers

37  aka general purpose registers, these are

 AX - register  BX - Base register  CX - Counter register  DX - Data register

 each are 16-bit long and can also be accessed as two 8-bit registers  AX  AH & AL  BX  BH & BL  CX  CH & CL  DX  DH & DL

 The 80386 introduced an extended 32-bit general purpose registers named EAX, EBX, ECX and EDX

8086/8088 Data Registers

38

 AX register  is used for operations involving input/output and arithmetic

 BX register  given the name base register because it is the only general purpose register that can be used as an index in indirect addressing  can also be used for computations

 CX register  usually used to control the number of times a loop is repeated or a value to shift bits left or right in bit shifting operations  can also be used for computations

 DX register  is used for operations involving input/output and most arithmetic 8086/8088 Address Registers

39  Segment registers: used to store starting address of memory segments

 Code Segment register

 Data Segment register

 Stack Segment register

 Extra Segment register

 Index registers: used for indexed addressing and string operations

 Source

 Destination Index register

 Pointer registers: used to store offset address within memory segments

 Instruction Pointer register

 Stack Pointer register

 Base Pointer register

 All the above address registers are 16-bit long in 8086/8088 8086/8088 Segment Registers

40

 CS register: used to hold starting address of program’s code segment

 DS register: used to hold starting address of program’s data segment

 SS register: used to hold starting address of program’s stack segment

 ES register: used to hold starting address of programmers defined extra data segment

 FS and GS registers: additional extra segment registers introduced by the 80386 8086/8088 Pointer Registers

41

 IP (Instruction Pointer) register

 used to locate a specific location within the code segment

 used to hold offset address of the next instruction to be executed

 SP (Stack Pointer) register

 used to hold offset address of the top of the stack segment

 points to the current word being processed in the stack

 BP (Base Pointer) register

 used to point to a specific location in the stack 8086/8088 Index Registers

42

 SI (Source Index) & DI (Destination Index) registers

 are used to locate a specific location within the data segment

 both are used in string handling operations. In this context, SI is associated with the DS register while DI is associated with the ES register

Flags Register

43

 Is the in Intel x86 microprocessors that shows the current state of the processor

 In 8086 is 16 bits wide, among which 9 are active

 They are modified automatically by the processor after instruction execution, which allows to determine the type of the result and also conditions to transfer control to other parts of the program Flags Register …

44

 The flags bits has two groups  Status flags: reflect the result of an operation executed by the processor  SF, ZF, AF, CF, PF & OF  Control flags: enable or disable certain operations of the processor  (TF)  flag (IF)  (DF)

Flags Register: control flags

45

 The Trap Flag  Permits operation of the processor in single-step mode  Setting TF (TF=1) puts the processor into single step mode for debugging, where the processor automatically generates an internal interrupt after each instruction, allowing a program to be inspected as it executes instruction by instruction

 The  Indicates that external , such as keyboard entry, are to be processed or ignored  Clearing IF (IF=0) disables interrupts

 The Direction Flag  Determines left or right direction for moving or comparing string (character) data  If DF=1, the string instruction will automatically decrement the pointer Flags Register: Status Flags

46

 SF (Sign): Indicates the resulting sign of an arithmetic operation (0 = positive and 1 = negative)

 ZF (Zero): Indicates the result of an arithmetic or comparison operation (0 = nonzero and 1 = zero result)

 PF (Parity): indicates the number of 1-bits that result from an operation. (0=even parity and 1 = odd parity)

 AF (Auxiliary Carry): contains a carry out of bit 3 into bit 4 in an arithmetic operation  OF (Overflow): indicates overflow of a high-order(leftmost) bit following in a signed arithmetic operation

 CF(Carry): contains carries from a high-order bit following an unsigned arithmetic operation; also contains the contents of the last bit of a shift or rotate operation