Chapter 5: Computer Systems OrganizationObjectivesIntroductionPowerPoint PresentationThe Components of a Computer SystemSlide 6Memory and CacheMemory and Cache (continued)Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Cache MemoryInput/Output and Mass StorageInput/Output and Mass Storage (continued)Slide 18Slide 19Slide 20Slide 21Slide 22The Arithmetic/Logic UnitThe Arithmetic/Logic Unit (continued)Slide 25The Control UnitMachine Language InstructionsSlide 28Machine Language Instructions (continued)Slide 30Control Unit Registers and CircuitsSlide 32Putting All the Pieces Together—the Von Neumann ArchitectureSlide 34Non-Von Neumann ArchitecturesNon-Von Neumann Architectures (continued)Slide 37Slide 38Slide 39Summary of Level 2Summary of Level 2 (continued)SummaryChapter 5: Computer Systems OrganizationInvitation to Computer Science,Java Version, Third EditionInvitation to Computer Science, Java Version, Third Edition2ObjectivesIn this chapter, you will learn aboutThe components of a computer systemPutting all the pieces together—the Von Neumann architectureNon-Von Neumann architecturesInvitation to Computer Science, Java Version, Third Edition3IntroductionComputer organization examines the computer as a collection of interacting “functional units”Functional units may be built out of the circuits already studiedHigher level of abstraction assists in understanding by reducing complexityInvitation to Computer Science, Java Version, Third Edition4Figure 5.1The Concept of AbstractionInvitation to Computer Science, Java Version, Third Edition5The Components of a Computer SystemVon Neumann architecture has four functional unitsMemoryInput/OutputArithmetic/Logic unitControl unitSequential execution of instructionsStored program conceptInvitation to Computer Science, Java Version, Third Edition6Figure 5.2Components of the Von Neumann ArchitectureInvitation to Computer Science, Java Version, Third Edition7Memory and CacheInformation stored and fetched from memory subsystemRandom access memory maps addresses to memory locationsCache memory keeps values currently in use in faster memory to speed access timesInvitation to Computer Science, Java Version, Third Edition8Memory and Cache (continued)RAM (random access memory)Memory made of addressable cellsCurrent standard cell size is 8 bitsAll memory cells accessed in equal timeMemory addressUnsigned binary number N longAddress space is then 2N cellsInvitation to Computer Science, Java Version, Third Edition9Figure 5.3Structure of Random Access MemoryInvitation to Computer Science, Java Version, Third Edition10Memory and Cache (continued)Parts of the memory subsystemFetch/store controllerFetch: Retrieve a value from memoryStore: Store a value into memoryMemory address register (MAR)Memory data register (MDR)Memory cells with decoder(s) to select individual cellsInvitation to Computer Science, Java Version, Third Edition11Memory and Cache (continued)Fetch operationThe address of the desired memory cell is moved into the MARFetch/store controller signals a fetch, accessing the memory cellThe value at the MAR’s location flows into the MDRInvitation to Computer Science, Java Version, Third Edition12Memory and Cache (continued)Store operationThe address of the cell where the value should go is placed in the MARThe new value is placed in the MDRFetch/store controller signals a store, copying the MDR’s value into the desired cellInvitation to Computer Science, Java Version, Third Edition13Memory and Cache (continued)Memory registerVery fast memory locationGiven a name, not an addressServes some special purposeModern computers have dozens or hundreds of registersInvitation to Computer Science, Java Version, Third Edition14Figure 5.7Overall RAM OrganizationInvitation to Computer Science, Java Version, Third Edition15Cache MemoryMemory access is much slower than processing timeFaster memory is too expensive to use for all memory cellsLocality principleOnce a value is used, it is likely to be used againSmall size, fast memory just for values currently in use speeds computing timeInvitation to Computer Science, Java Version, Third Edition16Input/Output and Mass StorageCommunication with outside world and external data storageHuman interfaces: Monitor, keyboard, mouseArchival storage: Not dependent on constant powerExternal devices vary tremendously from each otherInvitation to Computer Science, Java Version, Third Edition17Input/Output and Mass Storage (continued)Volatile storageInformation disappears when the power is turned offExample: RAMNonvolatile storageInformation does not disappear when the power is turned offExample: Mass storage devices such as disks and tapesInvitation to Computer Science, Java Version, Third Edition18Input/Output and Mass Storage (continued)Mass storage devicesDirect access storage deviceHard drive, CD-ROM, DVDUses its own addressing scheme to access dataSequential access storage deviceTape driveStores data sequentiallyUsed for backup storage these daysInvitation to Computer Science, Java Version, Third Edition19Input/Output and Mass Storage (continued)Direct access storage devicesData stored on a spinning diskDisk divided into concentric rings (sectors)Read/write head moves from one ring to another while disk spinsAccess time depends onTime to move head to correct sectorTime for sector to spin to data locationInvitation to Computer Science, Java Version, Third Edition20Figure 5.8Overall Organization of a Typical DiskInvitation to Computer Science, Java Version, Third Edition21Input/Output and Mass Storage (continued)I/O controllerIntermediary between central processor and I/O devicesProcessor sends request and data, then goes on with its workI/O controller interrupts processor when request is completeInvitation to Computer Science, Java Version, Third Edition22Figure 5.9Organization of an I/O ControllerInvitation to Computer Science, Java Version, Third Edition23The Arithmetic/Logic UnitActual computations are performedPrimitive operation circuits Arithmetic (ADD)Comparison (CE)Logic (AND) Data inputs and results stored in registersMultiplexor selects desired outputInvitation to Computer Science, Java Version, Third Edition24The Arithmetic/Logic Unit (continued)ALU