Tài liệu phục vụ cho học tập nghiên cứu về Memory, tiếng anh chuyên ngành Công nghệ thông tin

Tài liệu phục vụ cho học tập nghiên cứu về Memory, tiếng anh chuyên ngành Công nghệ thông tin Tài liệu phục vụ cho học tập nghiên cứu về Memory, tiếng anh chuyên ngành Công nghệ thông tin Tài liệu phục vụ cho học tập nghiên cứu về Memory, tiếng anh chuyên ngành Công nghệ thông tin

Group Computer Memories Members list Nguyễn Thanh Tùng Nguyễn Lê Thành Tâm Nguyễn Trung Huy Nguyễn Khánh Duy Nguyễn Quốc Châu Nguyễn Thị Mỹ Hạnh Nguyễn Minh Trí INTRODUCTION OF MEMORIES • What is a storage device and why is it needed? • An overview of computer memory INTRODUCTION What is a storage device? • A storage device is a piece of computer hardware used for saving, carrying and pulling out data • It almost saves all data and applications in a computer except for hardware firmware • It comes in different shapes and sizes depending on the needs and functionalities INTRODUCTION Types of Storage devices Magnetic Storage Device Optical Storage Device uses lasers and lights as its mode of saving and retrieving data Online and Cloud is now becoming widespread as people access data from different devices one of the most popular types of storage used Flash Memory Device is now replacing magnetic storage device as it is economical, more functional and dependable Paper Storage method used by early computers for saving information INTRODUCTION Why is Storage necessary? All computers need storage On a modern computer, storage comes in two forms: temporary and long-term • Temporary storage: Supplied as memory, or RAM Memory is where the processor does its work, where programs run, and where information is stored while it’s being worked on • Long-term storage: Provided by storage media Storage media includes disk drives, flash drives, media cards, and CDs and DVDs INTRODUCTION An overview of computer memory • A memory is used to store data and instructions • The memory is divided into large number of small parts called cells  Each location or cell has a unique address, which varies from zero to memory size minus one INTRODUCTION Primary Memory/Main Memory • Only holds those data and instructions on which the computer is currently working • Has a limited capacity and data is lost when power is switched off • Generally made up of semiconductor device • Divided into two subcategories RAM and ROM INTRODUCTION Secondary Memory • Known as external memory or non-volatile • Slower than the main memory • Used for storing data/information permanently • CPU directly does not access these memories, instead they are accessed via input-output routines • For example, disk, CD-ROM, DVD, etc TYPES OF MEMORIES EEPROM (E2PROM) • A type of non-volatile memory • Used in computers, integrated in microcontrollers for smart cards and remote keyless systems, and other electronic devices • To store relatively small amounts of data by allowing individual bytes to be erased and reprogrammed TYPES OF MEMORIES Flash Memory • A modern type of EEPROM • Can be erased and rewritten faster than ordinary EEPROM, and newer designs has the feature that is very high endurance (exceeding 1,000,000 cycles) • Except these types, there are other types of non-volatile memory including optical storage media, such as CD-ROM (analogous to MROM) TYPES OF MEMORIES Secondary memory • Stores your computer's software resources, including: operating system, programs, and data • Connected to devices in the form of access • Large capacity • Slow speed • Information is not lost when the power is turnedoff Long term data storage Storage capacity and speed: Da ta Da ta TYPES OF MEMORIES A storage device’s performance is measured by: • Capacity: The number of byte of data that a device can hold • Access Time: The amount of time, in milliseconds , it takes the device to begin reading data Storage Device TYPES OF MEMORIES Floppy disk • Commonly used in storing portable data • Especially with very old machines often use a floppy disk to store the operating system • Used to start a DOS-based session  Capacity: 720KB to 1,44MB  Access time: 100ms TYPES OF MEMORIES Hard Drives Hard drives are "immutable" types of memory that don't lose data when they stop supplying power to them  Capacity: up to 80GB  Access time: to 12ms TYPES OF MEMORIES An optical drive A type of device used to read optical discs  uses a device that emits a laser beam that hits the surface of the optical disc  reflected back on the receiver and decoded into a signal TYPES OF MEMORIES Magnetic Memory Hard Disks High-speed, high-capacity storage devices • Contain metal disks called platters • Contain two or more stacked platters with read/write heads for each side • Can be divided into partitions to enable computers to work with more than one operating system TYPES OF MEMORIES Floppy disks • A disk or diskette is a portable storage medium • High-density floppy disks that are commonly used today store 1,44MB of data • Disks work with a disk drive TYPES OF MEMORIES Optical Storage Media • CD-ROM stands for Compact Disc-Read Only Memory • CD-ROM drives can not write data discs • Standard CD storage capacity is about 700 MB, DVD about 17GB TYPES OF MEMORIES Optical Storage Media • Read slower than magnetic disk (hard drive) • Stores large amount of data in some formats as much as the entire hard disk • Reads data by focusing a laser-generated beam of light on discs surface TYPES OF MEMORIES CD-R CD-RW • CD-R stands for Compact Disc Recordable • CD-RW stands for Compact Disc Rewritable • Discs can be read and written to Discs can only be written to "once" • Discs can be recorded multiple times • CD-R drivers are capable of reading and writing data • CD-RW drives are capable of reading, writing to many times, and erasing data TYPES OF MEMORIES DVD-ROM Discs and Drives • Stands for Digital Video Disc • Similar to CD-ROM technology • Capable of storing up to 17GB of data • The data transfer rate of DVD drivers is comparable to that of hard disk drives • DVD-R and DVD-RW drives have the ability to read/write data TYPES OF MEMORIES Soild State Storage Devices • Use nonvolatile memory chips to retain data • Do not have moving parts • They’re small, lightweight, reliable, and portable Example: Smart Card, Flash Memory, PC Card, Memory Stick, Compact Flash Memory, Micro Drive ” ... recorded multiple times • CD-R drivers are capable of reading and writing data • CD-RW drives are capable of reading, writing to many times, and erasing data TYPES OF MEMORIES DVD-ROM Discs and... They’re small, lightweight, reliable, and portable Example: Smart Card, Flash Memory, PC Card, Memory Stick, Compact Flash Memory, Micro Drive ”  ... permanently • CPU directly does not access these memories, instead they are accessed via input-output routines • For example, disk, CD-ROM, DVD, etc TYPES OF MEMORIES • Primary or main memory • Secondary