1. Lecture # 10 Processors Microcomputer Processors

2. CPU  The CPU is the computer’s “brain” that manipulates data.  It is located on the motherboard.  Single or multiple processing chips.

4. CPU’s Two Basic Parts 1.Control unit 2.Arithmetic logic unit

6. Control Unit  Manages all the computer’s resources  The control unit directs the flow of data through the CPU and to and from other devices.  The control unit stores the CPU's microcode, which contains the instructions for all the tasks the CPU can perform.

7. Arithmetic Logic Unit  Performs the CPU’s arithmetic and logical operations.  Arithmetic: Addition, subtraction, multiplication, division.  Logical: Comparisons(, =,!=)  The ALU is connected to a set of registers—small memory areas in the CPU, which hold data and program instructions while they are currently being processed.

8. Machine Cycle  The completed series of steps the CPU takes to execute an instruction.  Two Cycles: Instruction cycle Execution cycle

9. Instruction Cycle  Fetching  Decoding During the instruction cycle, the CPU "fetches" a command or data from memory and "decodes" it for the CPU

10. Execution Cycle  Executing  Storing During the execution cycle, the CPU carries out the instruction, and may store the instruction's result in memory.

12. The CPU performance measurement Millions of Instructions Per Second (MIPS) Billions of Instructions Per Second (BIPS)

13. Pipelining  The control unit begins a new machine cycle before the current cycle is completed  Executions are performed in stages: When the first instruction completes the “Fetching" stage, it moves to the “Decode” stage and a new instruction is fetched.

14. Memory  Allows the CPU to store and retrieve data quickly.  Two Kinds of built-in Memory: Non-volatile Memory (Permanent) Volatile memory (Non-Permanent)

15. Memory Read-only memory (ROM): nonvolatile  Only Read and Used, not CHANGED  It holds instructions that run the computer when the power is first turned on.  PROM Chips– Instructions that power the devices. Random-access memory (RAM): volatile  RAM stores data and program code needed by the CPU.  The contents of RAM change rapidly and often.  SIMMs and DIMM Chips

16. To Request a byte of data, the CPU sends a memory address to RAM. Memory Address is a number that indicates a location on the memory chips.

17. Other Kinds of RAM Static & Dynamic  Dynamic RAM (DRAM) chips must be recharged with electricity very frequently, or they will lose their contents.  Static RAM (SRAM) does not need to be recharged as often as DRAM, and can hold its contents longer.  Another type of RAM, called flash memory, can store its contents after power is turned off. Used in Digital cameras,MP3 players, USB storage Device.

18. Factors Affecting Processing Speed  Registers – temporary memory area – 32 bit, 64 bit.  Memory and computing power - RAM  System clock – Hz – cycles per second – GHz (Billions of Cycles per second), 3GHz  The bus – the highway  The data bus – Connect CPU & devices  The address bus – Connect CPU & RAM  Cache memory – L1(CPU resident), L2 (External

20. More RAM = Better Performance! minimize “swapping

21. Bus Types  Industry standard architecture (ISA) bus is a 16 bit data bus – connect devices to the CPU.  Local bus – To connect faster devices to CPU. Internal bus.  Peripheral Component Interconnect (PCI) bus – fast 32 and 64 bit, audio, Video and graphics.  Accelerated Graphics Port (AGP) bus -video  Universal Serial Bus (USB) – fast – hot-swappable  IEEE 1394 (FireWire)- fast –cameras.

22. Data Transfer Rate  The amount of data buses can transfer in a second.  Measured in megabits per second (Mbps) or megabytes per second (MBps)

23. Cache memory  It speeds processing by storing frequently used data or instructions in its high-speed memory.  It is present in several places in a computer.  L1 cache: CPU Resident cache, 256KB built-in, holds instructions that have recently run.  L2 cache: Earlier present on motherboard, now on CPU, 512 KB or 1024 KB, holds upcoming instructions.  L3 cache: Motherboard Resident, not necessary, holds possible instructions

24. Microcomputer Processors

25.  Intel  Advanced Micro Devices (AMD)  Motorola processors  RISC  Parallel Processing

26. Intel Processors  Since 1978, Intel's processors have evolved from the 8086 and the 8088 to the 80286, 80386 and 80486, to the Pentium family of processors. All are part of the 80x86 line.  Intel's Pentium family of processors includes the Pentium, Pentium Pro, Pentium with MMX, Pentium II, Pentium III, IV, Celeron, and Xeon processors.  The earliest Intel processors included only a few thousand transistors. Today's Pentium processors include 9.5 million transistors or more.

27. Latest Technology - Intel  Speed doubles every 18 months.  Pentium 4- up to 3.2 GHz, 50 Million transistors  Pentium III /Xeon- up to 2.0 GHz, 50 Million transistors.  Celeron- up to 1.8 GHz, 40 Million transistors  Itanium- up to 2 GHz, 32 bit.  Centrino Mobile Technology.

29. CPUs Used in Personal Computers – AMD Processors  Advanced Micro Devices was long known as a provider of lower-performance processors for use in low-cost computers.  With its K6 line of processors, AMD challenged Intel's processors in terms of both price and performance.  With the Athlon, AMD broke the 1.0 GHz barrier, claiming the fastest processor title for the first time in IBM-compatible computers.

31. CPUs Used in Personal Computers – Motorola Processors  Motorola makes the CPUs used in Macintosh (680x0) and PowerPC computers.  Macintosh processors use a different basic structural architecture than IBM-compatible PC processors.  With the release of the G3 and G4 PowerPC processors, Macintosh computers set new standards for price and performance.  New G5, 64-bit.

32. Apple’s G4 computers are based on Motorola processors

33. CPUs Used in Personal Computers - RISC Processors Most PCs are based on complex instruction set computing (CISC) chips which contain large 200-300 instruction sets. Reduced Instruction Set Computing (RISC) processors use smaller instruction sets. This enables them to process more instructions per second than (CISC) chips. RISC processors are found in Apple's PowerPC systems, workstations. Popular in minicomputers (AS/400), and mainframes.

34. Compaq’s Alpha Server computers are based on RISC processors

35. CPUs Used in PC’s - Parallel Processing or Symmetric multiprocessing (SMP) In parallel processing, multiple processors are used in a single system, enabling them to share processing tasks.  In a Massively Parallel Processor (MPP) system, many processors are used.  Some MPP systems utilize thousands of processors simultaneously.