Input / Output Week 6

1. Input / OutputWeek 6 Computer Architecture Computer Architecture

2. Review External Memory • English words & ideas you must know: • Head • Sector • Track • Cylinder • Platter • Seek-Time • Spindle • Spindle Speed • RPM (Revolutions Per Minute) • Rotational delay • Access time • CAV (Constant Angular Velocity) • CLV (Constant Linear Velocity) • Spiral Computer Architecture

3. What we will learn today • Collect Homework • Review last class • Input / Output • External Devices • I/O Modules • QUIZ Computer Architecture

4. External Memory • Magnetic Disk • Hard Disk • Floppy • Optical Disk • CD-ROM, CD-R, CD-RW • DVD • Magnetic Tape Computer Architecture

5. Magnetic Disk Performance • Capacity • Seek Time (Minimum / Average) • Spindle Speed • Average Rotational delay • Maximum transfer rate • Bytes / sector • Sectors / track • Tracks / cylinder • Cylinders Computer Architecture

6. Example • Read 400 KB file • Average seek time – 7 ms • 1024 Bytes / sector; 200 Sectors / track • Rotational Speed – 15,000 rpm Computer Architecture

7. Optical Memory • CD-ROM (compact disk – read only memory) • No concentric circles (like hard disk) – spiral track • CLV – Constant Linear Velocity • CAV – Constant Angular Velocity • Block format • 12 Bytes – SYNC • 4 Bytes – ID • 2048 Bytes – Data • 288 Bytes - ECC (Error Correcting Code) Computer Architecture

8. Magnetic Tape • Sequential Access • Parallel Tracks • 9, 18, 36 tracks • Recording • Parallel recording • Serial Recording • Serpentine recording Computer Architecture

9. External Devices • Human readable • Printer • Video Display (Monitor) • Machine readable • Hard Drive / Floppy • CD-ROM • Communications • Networking Computer Architecture

10. External Devices - Connections • System Bus • I/O Module • External device • Controller • Device Computer Architecture

11. I/O Modules • Functions • Control and Timing • Processor Communication • Device Communication • Data Buffering • Error Detection Computer Architecture

12. Control and Timing • Coordinate the flow of traffic between internal resources and external devices • Main memory • System bus • Processor time Computer Architecture

13. Processor Communication • Command decoding • Data • Status reporting • Address recognition Computer Architecture

14. Device Communication • Commands • Status information • Data Computer Architecture

15. Data Buffering • Essential task!! • Used to match speed differences • Data can be sent / received in a burst • Less interrupts Computer Architecture

16. Error Detection • Mechanical errors • Electrical errors • Software errors • Usually has Error Detection Code Computer Architecture

17. I/O Module Structure Data linesDataStatus Control Address Lines Control Lines Data Registers External Device Logic Status Registers External Device Logic I/O Logic Computer Architecture

18. What you know now • Input / Output • External Devices • I/O Modules Computer Architecture

19. Reading • http://en.wikipedia.org/wiki/Input/output • http://en.wikipedia.org/wiki/Port-mapped_I/O Next Lecture • Input / Output - Continued Computer Architecture

20. Reading Next Lecture • Input / Output - Continued Computer Architecture

21. Self-PreparationStudy GuideWeek 6 1. What are the major functions of an I/O Module?2. What are three broad classifications of external, or peripheral, devices?3. What is buffering? Why is it important? Computer Architecture