PPT Slide
Interrupt Structure (continued)
- Causes of interrupts:
- System call (syscall instruction)
- Timer expires (value of timer register reaches 0)
- Disk I/O completed
- Program performed an illegal operation:
- ip = 0 : attempted to execute an undefined instruction
- ip = 1 : attempted to execute a system instruction while in user mode
- ip = 2 : address out of bounds while in user mode (address is less than base or greater than bound)