cs8421_lect_02_fall0..

CS 8421 Computing Systems, Dr. Garrido

CS8421

8-11-2007

ClassWill

Start Momentarily…

(Lecture 2)

CS8421 Computing SystemsDr. Jose M. Garrido


CS8421Real-Time Applications and Examples

• Vehicle systems• Traffic control• Process control• Medical systems• Military RT

systems• Manufacturing

Robots systems• Security control

• Telecommunication systems

• Computer games• Multimedia

systems• Household

appliance monitoring & control

• Building energy control


CS8421Properties of Real-Time Systems

• Timeliness - the system must perform operations in timely manner

• Reactiveness - the system continuously responds to (random) events

• Concurrency - multiple simultaneous activities are carried out

• Distribution - tasks cooperate in multiple computing sites


CS8421RTS Time Issues

• The goal is to reduce two specific intervals:– service time - the interval taken to

compute a response to a given input– latency - the interval between the

time of occurrence of an input and the time at which it starts being serviced

• The sum of these two intervals represents the response time. This must be shorter than the deadline for this type of input.


CS8421Architecture

•Architecture refers to the attributes visible to the programmer–Instruction set–Number of bits used for data representation

–I/O mechanisms–Addressing techniques.

•Is there a multiply instruction?


CS8421Organization

•Organization refers to how features are implemented–Control signals–Interfaces–Memory technology.

•Is there a hardware multiply unit or is it done by repeated addition?


CS8421Architecture & Organization

•All Intel x86 family share the same basic architecture

•The IBM System/370 family share the same basic architecture

•This gives code compatibility–At least backwards

•Organization differs between different versions


CS8421Structure & Function

•Structure is the way in which components relate to each other

•Function is the operation of individual components as part of the structure


CS8421Computer Architecture

Overview

Components of a computer system:

• CPU• Main Memory• Secondary Storage• I/O Devices• Bus• Operating System


CS8421General System Structure


CS8421Computer Functions

The computer functions are:

•Data processing•Data storage (memory)•Data movement (I/O)•Control


CS8421Computer Functional

View


CS8421Data Movement


CS8421Data Storage


CS8421Processing from/to Storage


CS8421Processing from Storage to

I/O


CS8421Structure - Top Level

Computer

Main Memory

InputOutput

SystemsInterconnection

Peripherals

Communicationlines

CentralProcessing Unit

Computer


CS8421Structure - The CPU

Computer Arithmeticand Logic Unit

ControlUnit

Internal CPUInterconnection

Registers

CPU

I/O

Memory

SystemBus

CPU


CS8421Structure - The Control Unit

CPU

ControlMemory

Control Unit Registers and Decoders

SequencingLogic

ControlUnit

ALU

Registers

InternalBus

Control Unit


CS8421ENIAC - background

• Electronic Numerical Integrator And Computer

• Eckert and Mauchly• University of Pennsylvania• Trajectory tables for weapons • Started 1943• Finished 1946

– Too late for war effort• Used until 1955


CS8421ENIAC - Details

• Decimal (not binary)• 20 accumulators of 10 digits• Programmed manually by switches• 18,000 vacuum tubes• 30 tons• 15,000 square feet• 140 kW power consumption• 5,000 additions per second


CS8421von Neumann/Turing

• Stored Program concept• Main memory store programs and data• ALU operating on binary data and binary

code• Control unit interpreting instructions from

memory and executing• Input and output equipment operated by

control unit• Princeton Institute for Advanced Studies

– IAS• Completed 1952


CS8421Structure of von Neumann Machine


CS8421IAS - details

• 1000 x 40 bit words– Binary number– 2 x 20 bit instructions

• Set of registers (storage in CPU)– Memory Buffer Register– Memory Address Register– Instruction Register– Instruction Buffer Register– Program Counter– Accumulator– Multiplier Quotient


CS8421Structure of IAS – detail


CS8421Functioning of the IAS Computer

• Repetitively performing an instruction cycle

• An instruction cycle has two subcycles– Fetch cycle – the “opcode” of

instruction and its address are loaded into registers IR and MAR

– Execute cycle -- interpretation of the “opcode” and execution of the instruction


CS8421Instructions of the IAS Computer

• The IAS computer had 21 instructions• These instructions are grouped as:

– Data transfer– Unconditional branch– Conditional branch– Arithmetic– Address modify


CS8421Commercial Computers

• 1947 - Eckert-Mauchly Computer Corporation

• UNIVAC I (Universal Automatic Computer)• US Bureau of Census 1950 calculations• Became part of Sperry-Rand Corporation• Late 1950s - UNIVAC II

– Faster– More memory


CS8421IBM

• Punched-card processing equipment• 1953 - the 701

– IBM’s first stored program computer– Scientific calculations

• 1955 - the 702– Business applications

• Lead to 700/7000 series• The IBM 7094 introduced the data channel,

a smaller specialized I/O processor


CS8421Transistors

• Replaced vacuum tubes• Smaller• Cheaper• Less heat dissipation• Solid State device• Made from Silicon (Sand)• Invented 1947 at Bell Labs• William Shockley et al.


CS8421Transistor Based Computers

• Second generation machines• NCR & RCA produced small transistor

machines• IBM 7000• DEC - 1957

– Produced PDP-1


CS8421Microelectronics

• Literally - “small electronics”• A computer is made up of gates, memory

cells and interconnections• These can be manufactured on a

semiconductor• e.g. silicon wafer• Used in the third generation of computers


CS8421Generations of Electronics

• Vacuum tube - 1946-1957• Transistor - 1958-1964• Small scale integration - 1965 on

– Up to 100 devices on a chip• Medium scale integration - to 1971

– 100-3,000 devices on a chip• Large scale integration - 1971-1977

– 3,000 - 100,000 devices on a chip• Very large scale integration - 1978 to date

– 100,000 - 100,000,000 devices on a chip• Ultra large scale integration

– Over 100,000,000 devices on a chip


CS8421Moore’s Law

• Increased density of components on chip• Gordon Moore - cofounder of Intel• Number of transistors on a chip will double every

year• Since 1970’s development has slowed a little

– Number of transistors doubles every 18 months• Cost of a chip has remained almost unchanged• Higher packing density means shorter electrical

paths, giving higher performance• Smaller size gives increased flexibility• Reduced power and cooling requirements• Fewer interconnections increases reliability


CS8421Growth in CPU Transistor Count


CS8421IBM 360 series

• 1964• Replaced (& not compatible with) 7000

series• First planned “family” of computers

– Similar or identical instruction sets– Similar or identical O/S– Increasing speed– Increasing number of I/O ports (i.e. more

terminals)– Increased memory size – Increased cost

• Multiplexed switch structure


CS8421DEC PDP-8

• 1964• First minicomputer • Did not need air conditioned room• Small enough to sit on a lab bench• $16,000

– $100k+ for IBM 360• Embedded applications & OEM• BUS STRUCTURE


CS8421DEC - PDP-8 Bus Structure

OMNIBUS

ConsoleController

CPU Main Memory I/OModule

I/OModule


CS8421Semiconductor Memory

• 1970• Fairchild• Size of a single core

– i.e. 1 bit of magnetic core storage• Holds 256 bits• Non-destructive read• Much faster than core• Capacity approximately doubles each year


CS8421Intel

• 1971 - 4004 – First microprocessor– All CPU components on a single chip– 4 bit

• Followed in 1972 by 8008– 8 bit– Both designed for specific applications

• 1974 - 8080– Intel’s first general purpose

microprocessor


CS8421Improving Speed

• Pipelining• On board cache• On board L1 & L2 cache• Branch prediction• Data flow analysis• Speculative execution


CS8421Performance Mismatch

• Processor speed increased• Memory capacity increased• Memory speed lags behind processor

speed


CS8421DRAM and Processor Characteristics


CS8421Trends in DRAM use


CS8421Pentium Evolution (1)

• 8080– first general purpose microprocessor– 8 bit data path– Used in first personal computer – Altair

• 8086– much more powerful– 16 bit– instruction cache, prefetch few instructions– 8088 (8 bit external bus) used in first IBM PC

• 80286– 16 Mbyte memory addressable– up from 1Mb

• 80386– 32 bit– Support for multitasking



• 80486– sophisticated powerful cache and

instruction pipelining– built in maths co-processor

• Pentium– Superscalar– Multiple instructions executed in parallel

• Pentium Pro– Increased superscalar organization– Aggressive register renaming– branch prediction– data flow analysis– speculative execution



• Pentium II– MMX technology– graphics, video & audio processing

• Pentium III– Additional floating point instructions for

3D graphics• Pentium 4

– Note Arabic rather than Roman numerals– Further floating point and multimedia

enhancements• Itanium

– 64 bits


CS8421PowerPC

• IBM, Motorola, Apple• Used in Apple Macintosh• RISC architecture

– 601– 603– 604– 620– 740/750 (G3)– G4– G5


CS8421What is a Program?

• A sequence of steps (instructions?)• For each step, an arithmetic or logical

operation is carried out• For each operation, a different set of

control signals is needed


CS8421Function of Control Unit

• For each operation a unique operation code is provided– e.g. ADD, MOVE

• A hardware segment accepts the code and issues the control signals

• This is the foundation for a computer!


CS8421Components

• The Control Unit and the Arithmetic and Logic Unit constitute the Central Processing Unit

• Data and instructions need to get into the system and results out– Input/output

• Temporary storage of code and results is needed– Main memory


CS8421Components: Top Level View


CS8421Instruction Cycle

• Two steps:– Fetch– Execute


CS8421Fetch Cycle

• Program Counter (PC) holds address of next instruction to fetch

• Processor fetches instruction from memory location pointed to by PC

• Increment PC– Unless told otherwise


CS8421Execute Cycle

• Instruction loaded into Instruction Register (IR)

• Processor interprets instruction and performs required actions


CS8421Categories of Actions

• Processor-memory– data transfer between CPU and main

memory• Processor I/O

– Data transfer between CPU and I/O module• Processing

– Some arithmetic or logical operation on data

• Control– Alteration of sequence of operations– e.g. jump

• Combination of above


CS8421Fetch/Decode/Execute/Interrupt

Cycle

• Instruction Fetch. The number of processor/bus cycles required depends on the width of the instruction and the width of the bus

• Decode. Determine what the instruction will actually do, in particular, what operands are required before the instruction can execute

• Operand Fetch - multiple operands may require multiple fetches

• Execute Instruction• Check for Interrupts.


CS8421Example of Execution

• The processor has a single data register, the accumulator, AC

• Both instructions and data are 16 bits long• Instruction format:

– 4 bits for the opcode, for 16 different opcodes

– 12 bits for the address (4K)• Opcodes: 1=load AC, 2=store AC, 5= add to

AC• Instruction format using Hex notation


CS8421Example of Program Execution


CS8421End of Lecture

End Of

Today’sLecture.

8-21-07

cs8421_lect_02_fall0..

Documents

ias computer

computer system

computer eckert

computer functions

binary data

structure of ias

computer functional

memory cells