8-11-2007

1. 8-11-2007 (Lecture 2) CS8421 Computing SystemsDr. Jose M. Garrido • Class • Will • Start • Momentarily…

2. 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 Real-Time Applications and Examples

3. Properties 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

4. RTS 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.

5. Architecture • 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?

6. Organization • 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?

7. Architecture & 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

8. Structure & Function • Structure is the way in which components relate to each other • Function is the operation of individual components as part of the structure

9. Computer Architecture Overview Components of a computer system: • CPU • Main Memory • Secondary Storage • I/O Devices • Bus • Operating System

10. General System Structure

11. Computer Functions The computer functions are: • Data processing • Data storage (memory) • Data movement (I/O) • Control

12. Computer Functional View

13. Data Movement

14. Data Storage

15. Processing from/to Storage

16. Processing from Storage to I/O

17. Structure - Top Level Computer Peripherals Central Processing Unit Main Memory Computer Systems Interconnection Input Output Communication lines

18. Structure - The CPU CPU Arithmetic and Logic Unit Computer Registers I/O System Bus CPU Internal CPU Interconnection Memory Control Unit

19. Structure - The Control Unit Control Unit CPU Sequencing Logic ALU Control Unit Internal Bus Control Unit Registers and Decoders Registers Control Memory

20. ENIAC - 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

21. ENIAC - 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

22. von 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

23. Structure of von Neumann Machine

24. IAS - 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

25. Structure of IAS – detail

26. Functioning 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

27. Instructions of the IAS Computer • The IAS computer had 21 instructions • These instructions are grouped as: • Data transfer • Unconditional branch • Conditional branch • Arithmetic • Address modify

28. Commercial 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

29. IBM • 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

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

31. Transistor Based Computers • Second generation machines • NCR & RCA produced small transistor machines • IBM 7000 • DEC - 1957 • Produced PDP-1

32. Microelectronics • 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

33. Generations 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

34. Moore’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

35. Growth in CPU Transistor Count

36. IBM 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

37. DEC 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

38. DEC - PDP-8 Bus Structure I/O Module Main Memory I/O Module Console Controller CPU OMNIBUS

39. Semiconductor 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

40. Intel • 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

41. Improving Speed • Pipelining • On board cache • On board L1 & L2 cache • Branch prediction • Data flow analysis • Speculative execution

42. Performance Mismatch • Processor speed increased • Memory capacity increased • Memory speed lags behind processor speed

43. DRAM and Processor Characteristics

44. Trends in DRAM use

45. Pentium 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

46. Pentium Evolution (2) • 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

47. Pentium Evolution (3) • 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

48. PowerPC • IBM, Motorola, Apple • Used in Apple Macintosh • RISC architecture • 601 • 603 • 604 • 620 • 740/750 (G3) • G4 • G5

49. What 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

50. Function of Control Unit • For each operation a unique operationcode is provided • e.g. ADD, MOVE • A hardware segment accepts the code and issues the control signals • This is the foundation for a computer!