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Data Storage Technology

Data Storage Technology. Chapter 5. Chapter Topics. Storage Device Characteristics. Speed Volatility Access method Portability Cost and capacity. Storage Device Characteristics. Speed – Primary Storage Wait state Secondary Storage Access time Data transfer rate Sector.

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Data Storage Technology

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  1. Data Storage Technology Chapter 5 Systems Architecture, Fourth Edition

  2. Chapter Topics Systems Architecture, Fourth Edition

  3. Storage Device Characteristics • Speed • Volatility • Access method • Portability • Cost and capacity Systems Architecture, Fourth Edition

  4. Storage Device Characteristics Speed – • Primary Storage • Wait state • Secondary Storage • Access time • Data transfer rate • Sector Systems Architecture, Fourth Edition

  5. Storage Device Characteristics Volatility • A storage device or medium is non-volatile if it holds data without loss over long periods of time. • A storage device or medium is volatile if it cannot reliably hold data for long periods of time. Systems Architecture, Fourth Edition

  6. Storage Device Characteristics Access Methods • Serial Access – stores and retrieves data items in a linear order. (Magnetic tape) • Random Access - access device is not restricted to any specific order when accessing data. (Hard Disk) • Parallel Access - a device that is capable of simultaneously accessing multiple storage locations. (Random Access Memory) Systems Architecture, Fourth Edition

  7. Storage Device Characteristics Secondary Storage Devices Systems Architecture, Fourth Edition

  8. Storage Device Characteristics Systems Architecture, Fourth Edition

  9. Storage Device Characteristics Memory Storage Hierarchy Systems Architecture, Fourth Edition

  10. Primary Storage Devices • Storing Electrical Signals • Random Access Memory • Read-Only Memory • Memory Packaging Systems Architecture, Fourth Edition

  11. Primary Storage Devices Storing Electrical Signals: • Data is represented as electrical signals. • Digital signals are used to transmit data to and from devices attached to the system bus. • Storage devices must accept electrical signals as input and output. Systems Architecture, Fourth Edition

  12. Primary Storage Devices Random Access Memory Characteristics: • Microchip implementation using semiconductors • Ability to read and write with equal speed • Random access to stored bytes, words, or larger data units Systems Architecture, Fourth Edition

  13. Primary Storage Devices Types of RAM: • Static RAM (SRAM) • Dynamic RAM (DRAM) • Synchronous DRAM (SDRAM) • Enhanced DRAM (EDRAM) • Ferroelectric RAM Systems Architecture, Fourth Edition

  14. Primary Storage Devices Systems Architecture, Fourth Edition

  15. Primary Storage Devices Read-Only Memory - a device that can store data permanently or semi permanently. • Firmware • EEPROM • Flash Systems Architecture, Fourth Edition

  16. Primary Storage Devices Memory Packaging Systems Architecture, Fourth Edition

  17. CPU Memory Access Physical Memory Organization Main memory can be regarded as a sequence of contiguous, or adjacent memory cells. Systems Architecture, Fourth Edition

  18. CPU Memory Access Systems Architecture, Fourth Edition

  19. CPU Memory Access Memory Allocation and Addressing -describes the assignment of specific memory addresses to system software, application programs and data. Systems Architecture, Fourth Edition

  20. CPU Memory Access Systems Architecture, Fourth Edition

  21. CPU Memory Access Memory Addressing: • Absolute Addressing – describes memory address operands that refer to actual physical memory locations. • Relative Addressing (Indirect Addressing) – automatically computes physical memory addresses. Systems Architecture, Fourth Edition

  22. CPU Memory Access Systems Architecture, Fourth Edition

  23. CPU Memory Access Systems Architecture, Fourth Edition

  24. Magnetic Storage Magnetic Storage • Exploit the duality of magnetism and electricity. • Electric current is used to generate a magnetic field. • A magnetic field can be used to generate electricity. Systems Architecture, Fourth Edition

  25. Magnetic Storage Systems Architecture, Fourth Edition

  26. Magnetic Storage Systems Architecture, Fourth Edition

  27. Magnetic Storage Systems Architecture, Fourth Edition

  28. Magnetic Storage Magnetic Tape • Ribbon of plastic with a coercible surface coating. • Mounted in a tape drive for reading and writing. • Compound the magnetic leakage problem by winding the tape upon itself. Systems Architecture, Fourth Edition

  29. Magnetic Storage Systems Architecture, Fourth Edition

  30. Magnetic Storage Systems Architecture, Fourth Edition

  31. Magnetic Storage Technology Focus Systems Architecture, Fourth Edition

  32. Magnetic Storage Magnetic Disk • Flat circular platters with metallic coatings that are rotated beneath read/write heads • Multiple platters can be mounted. • Once concentric circle is a track. • A fractional portion of a track is a cylinder. Systems Architecture, Fourth Edition

  33. Magnetic Storage Magnetic Disk Types: • Hard Disk – magnetic disk media with a rigid metal base. • Floppy Disk (Diskette) – uses a base of flexible or rigid plastic material. Systems Architecture, Fourth Edition

  34. Magnetic Storage Systems Architecture, Fourth Edition

  35. Magnetic Storage Systems Architecture, Fourth Edition

  36. Magnetic Storage Systems Architecture, Fourth Edition

  37. Magnetic Storage Systems Architecture, Fourth Edition

  38. Magnetic Storage Systems Architecture, Fourth Edition

  39. Optical Mass Storage Devices Advantages: • Higher recording density • Longer data life • Retain data for decades • Not subject to problems of magnetic decay and leakage Systems Architecture, Fourth Edition

  40. Optical Mass Storage Devices • Optical storage devices store bit values as variations in light reflection. • Storage medium is a surface of highly reflective material. • The read mechanism consists of a low-power laser and a photoelectric cell. Systems Architecture, Fourth Edition

  41. Optical Mass Storage Devices Systems Architecture, Fourth Edition

  42. Optical Mass Storage Devices Systems Architecture, Fourth Edition

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