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I/O Module - Coggle Diagram
I/O Module
Function
Interface with CPU and memory
Interface with one or more peripheral devices
Eg. I/O Devices
Input
Scanner
Mouse
Microphone
Controller
Keyboard
Output
Printer
Projector
Monitor
Speaker
Input & Output
Network cards
Fax Machine
Modem
Characteristic of isolated and memory mapped I/O
Uses special class of CPU intructions
Processor and I/O device (different memory located)
Memory mapped I/O (Share same memory location)
Transfer Mode
Interrupt-Initiated I/O
Overcomes processor having to wait long
Processor does not have to repeatedly check I/O module status
I/O module interrupts when ready
Direct Memory Access
Transfers data between peripherals and memory (Without CPU)
CPU may not be fast enough to keep up to the peripheral
DMAC can be used to transfer data (memory-I/O devices)
Programmed I/O
Use I/O intructions to transfer data
Data exchanged between CPU and I/O
Must wait until I/O operation complete
If CPU is faster there is wastage of CPU time
I/O Data Transfer
Asynchronous Serial Transfer
Character Oriented
Each character consists of a start bits, Character bits and stop bits
Asynchronous Communication Interface
Uses external clock signal
Transmitter and receiver clock generators doesn't have to be synchronized