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Input/ OutputBy Mohit Sehgal
What is Input/Output of a Computer?
• Connection with Machine
• Every machine has I/O (Like a function)
• In computing, input/output, or I/O, refers to the communication between an information processing system (such as a computer), and the outside world possibly a human, or another information processing system.
KeyboardUses an arrangement of buttons or keys,
to act as mechanical levers or electronic switches.
MousePointing device that functions by
detecting two-dimensional motion relative to its supporting surface
Types of I/O
•Interrupt I/O
•Programmed I/O
•DMA I/O (Direct Memory Access)
Interrupt I/O
In computing, an interrupt is an asynchronous signal indicating the need for attention or a synchronous event in software indicating the need for a change in execution.
Interrupt I/O
• CPU does not need to wait
• I/O Module interrupts when it is ready
Programmed I/O
Method of transferring data between the CPU and a peripheral such as a network adapter or an ATA storage device
Happens when software running on the CPU uses instructions that access I/O address space
Programmed I/O
CPU has control over the I/O
Downfall:
Uses a lot of CPU time
Direct Memory Access I/ORefers to data transfers initiated by a
device to access system memoryAllows certain hardware subsystems
within the computer to access system memory for reading and/or writing independently of the central processing unit
DMA I/ODMA controller takes over from CPU for I/O
DMA takes the load from the CPU
Input/ Output ProcessCPU checks I/O module device statusI/O then returns its statusCPU requests data transfer if I/O is readyI/O module gets data from deviceTransfers it to CPUOutput
Input Output I/O are getting more advancedNow I/O are doing the entire transferThis takes the strain off of CPU
Future of I/O