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Specific English for Electronic Information EngineeringGuangdong Ocean University1ppt课件课件Lesson15:MemeoryIndexPre-reading15.1 RAM(Random-access-memory)15.2 ROM(Read-only memory)15.3 EPROM(Erasable ProgrammableRead-only memory)15.4 EEPROM15.5 Flash memory15.6 Cache memory2ppt课件课件Pre-reading123 what is memory?ClassificationOf memory.Functions of different memories.Read the lesson,paying attention to the following questions.3ppt课件课件RemindtheWordsandexpressionsPrimaryQuantityPrincipalIntermediaryUtilizeApproximatelyVolatileElectronicSecondary 主要的，首要的主要的，首要的量，数量量，数量主要的，最重要的主要的，最重要的中间人，调解人中间人，调解人利用利用近似的近似的易变的，不稳定的易变的，不稳定的电子的电子的第二的第二的4ppt课件课件RemindtheWordsandexpressionsTemporarySpecificInterpretationSubsequentDisruptSemiconductor ErasableFirmwareModule暂时的暂时的详尽的详尽的解释解释随后的随后的中断的中断的半导体半导体可擦除的可擦除的固件固件模数模数5ppt课件课件RemindtheWordsandexpressionsHenceFabricationUltravioletRadiationConsiderablyEssentiallyFunctionalityCPUROM因此因此制造制造紫外线紫外线辐射辐射相当大地相当大地本质上的，基本本质上的，基本功能性功能性中央处理器中央处理器只读存储器只读存储器6ppt课件课件RemindtheWordsandexpressionsPrimary storageEPROMInstruction registerStorage registerAccumulatorRAMEEPROM主存储器主存储器可擦除可编程只读存储器可擦除可编程只读存储器指令寄存器指令寄存器缓冲寄存器缓冲寄存器累加器累加器随机存储器随机存储器电可擦除只读存储器电可擦除只读存储器7ppt课件课件Introduction(1)The memory is a part of the computer where programs and data are stored;(2)Memory is also called real memory or primary storage;(3)Is expressed as quantities of KB;1TB=1024GB，1GB=1024MB；1MB=1024KB；1KB=1024B；1Byte=8bit8ppt课件课件WordsandexpressionsInternal Real storagePrimary storageQuantityKBByteBit 内部的内部的实存储器实存储器主存储器主存储器量，数量的量，数量的KiloByte字节字节比特比特9ppt课件课件Functionofmemory(1)As an intermediary between the CPU and the rest of the computer system components;(2)As a sort of desktop on which you place the things are about to work;10ppt课件课件WordsandexpressionsIntermediaryComponents desktopUtilizeinstructions中间人，媒介中间人，媒介元器件元器件桌面桌面利用利用指令指令11ppt课件课件Mainmemory(1)Main memory is a RAM;(2)Data can be stored and retrieved at random12ppt课件课件WordsandexpressionsRAMRandom access memoryDeriveRetrieveRandomChipApproximately随机存储器随机存储器起源于起源于检索，恢复检索，恢复随机的随机的芯片芯片近似的近似的13ppt课件课件Mainmemory(1)The main memory is in an electronic or volatile state;(2)When computer is off,the main memory is empty.When it is on,the main memory can receive and hold a copy of the software instructions and data for processing.(3)Main memory is volatile,users save their work onto nonvolatile secondary storage(diskette or hard disk)14ppt课件课件WordsandexpressionsVolatileEmpty instructionsFrequentlyNonvolatileNonvolatile-secondary-StorageDisketteHard disk不稳定的，易变的不稳定的，易变的空的空的指令指令经常地经常地非易失的非易失的永久性存储永久性存储磁盘磁盘硬盘硬盘15ppt课件课件Purposeofthemainmemory(1)Storage of a copy of the main software program;(2)Temporary storage of a copy of application program instructions;(3)Temporary storage of data that has been input from the keyboard or other input device;(4)Temporary storage of data that has been produced as a result of process;16ppt课件课件WordsandexpressionsGeneral Load intoTemporarySpecific RetrieveInterpretationExecution SubsequentTransferred普遍的，一般的普遍的，一般的载入载入暂时的暂时的具体的，详尽的具体的，详尽的检索，取回检索，取回解释解释执行执行随后的随后的转换转换17ppt课件课件15.1Randomaccessmemory(1)RAM is used for short-time storage of data or program instructions;(2)The content of RAM can be read and changed;(3)RAM is volatile,is used as temporary storage;18ppt课件课件15.1RandomaccessmemoryRAM chips for computers:19ppt课件课件WordsandexpressionsShort-termVolatileElectricity supplyDisrupt短期的短期的不稳定的，易失的不稳定的，易失的电源供应电源供应中断中断20ppt课件课件15.2Read-onlymemory(1)On many microcomputer,the operating system is build in a chip rather than on a floppy disk;(2)“software in hardware”is called firmware;(3)Read-only memory is by far the most common form of firmware;(4)A ROM module contains a program by manufacture;(5)The program can be read but impossible to destroy by accidentally writing;21ppt课件课件WordsandexpressionsSemiconductorMounted onFloppy diskFirmwareAvailableBy farModuleDestroyaccidentally半导体半导体安装于安装于软盘软盘固件固件可用的可用的至今为止至今为止模块模块毁坏毁坏意外地意外地22ppt课件课件PROM(1)PROM（programmable ROM)is nonvolatile and may be written into only once;(2)The written process is performed electrically and performed by supplier or customer at a time later than the original chip fabrication.(3)PROM provides flexibility and convenience;23ppt课件课件WordsandexpressionsNonvolatileSupplierCustomerFabricationSpecialFlexibilityconvenience不易失的不易失的供应商供应商客户客户制造制造特殊的特殊的灵活的，柔韧的灵活的，柔韧的方便的方便的24ppt课件课件10.3EPROM(1)EPROM(erasable programmable read-only memory)is read and written electricity;(2)Before a writing operation,all the storage cells must be erased to the same initial state by exposure of the package chip to ultraviolet radiation;(3)The erasure process can be repeatedly;(4)Each erasure takes as much as 20minutes;(5)Has advantage of the multiple update capability;25ppt课件课件4M bit EPROM Toshiba TC574200Dshowing transparent window used to erase the chip10.3EPROM26ppt课件课件WordsandexpressionsStorage cellExposurePackaged chipUltravioletRadiationMultipleVirtuallyIndefinitelyComparableupdate存储单元存储单元暴露暴露封装芯片封装芯片紫外线紫外线辐射辐射多重的，复杂的多重的，复杂的实质的实质的不定期的，不明确的不定期的，不明确的可比较的可比较的更新更新27ppt课件课件15.4EEPROM(1)EEPROM(electricity erasable programmable read-only memory)can be written at any time without erasing prior contents;(2)The write operation takes considerably longer than the read operation(order of several hundred microsecond per byte;(3)EEPROM is more expensive and less dense,supporting fewer bits per chip;28ppt课件课件15.4EEPROM29ppt课件课件WordsandexpressionsPriorByte addressConsiderablyMicrosecondUpdateableIn placeOrdinaryBus controlData lineLess dense在在之前之前字节地址字节地址相当大的相当大的微秒微秒可更新的可更新的在适当位置在适当位置普通的普通的总线控制总线控制数据线数据线不密集不密集30ppt课件课件15.5Flashmemory(1)Flash memory is newest form of semiconductor memory,the speed can be reprogrammed;(2)Flash memory is intermediate between EPROM and EEPROM in both cost and functionality;(3)Uses an electrical erasing technology;(4)Can be erased in one or a few second;(5)Can erase blocks of memory,can not provide byte-level erasure;(6)Higher density;31ppt课件课件15.5Flashmemory32ppt课件课件WordsandexpressionsFlash memoryReprogrammedIntroduceIntermediateFunctionalityRather thanEntireTransistorAchieveHigh density闪速存储器闪速存储器改编改编引入，介绍引入，介绍调节，中间的调节，中间的功能性功能性而不是而不是全部全部晶体管晶体管获得，实现获得，实现高密度高密度33ppt课件课件15.6Cachememory(1)Cache memory can increase speed of transfer of instructions and data from secondary storage to the processor;(2)Cache memory is about 10 times faster than RAM;(3)Its storage capacity is smaller than RAMs capacity;34ppt课件课件WordsandexpressionsCache memoryTransferSecondary storageEssentiallyTemporary storageCapacityimmediately缓存缓存转移转移辅助存储器辅助存储器本质上的本质上的暂存存储器暂存存储器容量容量立刻立刻35ppt课件课件广东海洋大学广东海洋大学www.51 搜集整理搜集整理36ppt课件课件
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