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Interrupt IO
Interrupt IO An Interrupt-based I/O is a mechanism that allows a device to be notified when it has data to be read or written. Instead of the device con...
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Interrupt IO An Interrupt-based I/O is a mechanism that allows a device to be notified when it has data to be read or written. Instead of the device con...
Interrupt IO
An Interrupt-based I/O is a mechanism that allows a device to be notified when it has data to be read or written. Instead of the device continuously checking the device for data, it sets up a Interrupt Vector that tells the CPU when data is available.
Here's how it works:
A device (like a keyboard or a hard drive) connects to the computer through a Peripheral Control Unit (PCU).
The Interrupt Vector is a memory location that stores the addresses of all the device's interrupt service routines.
When data is available, the device writes the address of its interrupt service routine to the Interrupt Vector.
The Interrupt Service Routine is called by the CPU when an interrupt occurs.
The CPU then executes the interrupt service routine and processes the data received by the device.
Benefits of Interrupt-based I/O:
Efficiency: It reduces the CPU's overhead, as it only interrupts the device when data is available, saving time.
Flexibility: Devices can be added or removed dynamically without requiring the software to be recompiled.
Parallelism: Multiple devices can be connected and read or written to simultaneously, improving system performance.
Example:
Imagine a keyboard connected to a computer. When a key is pressed, the keyboard sends an interrupt signal to the computer. The computer then calls the keyboard's interrupt service routine, which processes the keypress and updates the display