updated: 2022-01-23_12:32:31-05:00

Interrupt

• Interrupt gives control to the operating system

Taking an Interrupt:

• Before fetch: check for pending interrupt
• With highest priority pending interrupt
  • Set Privilege Bit
  • Save context of user program on K-Stack
  • Use the interrupt number as index into ISV: jump to address
  • Run Interrupt service routine ...
  • Ensure the context of appropriate user process is on K-Stack
  • Unset Privilege Bit
  • Restore context from K-Stack
• Restart instruction pointed to by Program Couter for user code