Computer Science – Software | e-Consult

Hardware interrupts are generated by external devices to signal the CPU that they require attention. They are triggered by physical events, such as a key press, a network packet arrival, or a disk read completion. They are typically faster than software interrupts because they are directly triggered by hardware.

Example of a hardware interrupt: A keyboard press. When you press a key, the keyboard controller sends a hardware interrupt signal to the CPU. The CPU then executes the interrupt handler to determine which key was pressed and takes appropriate action.

Software interrupts are generated by instructions within a program. They are used to request services from the operating system, such as file I/O or system calls. They are slower than hardware interrupts because they involve a context switch to the operating system kernel.

Example of a software interrupt: A program using the INT instruction to request a file to be opened. This triggers a software interrupt, transferring control to the operating system's kernel, which then handles the file opening request.