Chapter 6 Input / Output

Chapter 6 Input / Output

1. Keyboard / Monitor

   • * Basic unit of exchange is the character - 128 different characters can be represented
     • *Characters
       • *Printable
         • *Control

2. Major functions for an I/O module

   • -> Control and Timing
     • -> Processor communication
       • -> Device communication
         • -> Data buffering
           • -> Error detecting

3. Programmed I/O

   • * overviewed of programmed I/O
     • *I/O cammands / instructions

4. Interrupt - driven I/O

   • -> Interrupt processing
     • -> Design issues

5. Three categories

   • -> Human readable suitable for communication with computer user
     • -> Machine readable - suitable for communicating with equipment
       • -> communication - suitable for communicating with remote devices

6. Firewire Serial Bus

   • *IEEE Standard 1394 , for a High performance Serial Bus .
     • * uses daisy configuration , with up to 63 devices connected off a single part.
       • * 1022 Firewire buses can be interconnected using bridges.
         • * Provides for automatic configuration
           • * No terminations and the system automatically performs a configurations functions to assign addresses.

7. Device identification

   • ->Bus arbitration(vectored)-gain control of the bus before it can raise the interrupt request line
     • ->Multiple interrupt lines-between the processor & I/O modules
       • Software poll-time consuming
         • Daisy chain(hardware poll,vectored),the interrupt acknowledge line is daisy chained through the module

8. External device

   • *Keyboard
     • *Monitor

9. Universal Series Bus

   • *Used for peripheral
     • *Default & interface for slower speed device
       • Multiple generation
         • USB 1.0 & 2.0 & 3.0 & 3.1
     • Controlled by a root host controller