Overview #
- Sent through the system bus (the main communication path between major components)
- Upon receiving an interrupt, the CPU immediately pauses execution and starts execution at a fixed location
- This is likely an interrupt service routine
- An interrupt vector is an array of low address memory that maps pointers from the interrupt time to the interrupt service routine address for execution
- Interrupts allow the OS to respond asynchronously to events
- Modern OS’s may not respond immediately depending on interrupt priority
- 2 interrupt lines: one for critical code and one that can be turned off when the CPU is executing important instructions
- The system clock is updated at every interrupt
How Interrupts Work #
- The hardware has an interrupt-request line that is sensed after every CPU instruction
- If there is a signal, it uses the value to index into the interrupt vector and run the interrupt service routine
Software Interrupts #
- Exceptions trigger software interrupts