Lecture 22 Objectives
At the end of today's class you should
KNOW:
- what is meant by interrupt-driven I/O
- why interrupts are useful
- how an interrupt is initiated and when it is recognized
- how interrupts can be prioritized
- the difference between the user and the supervisor stacks
- how the interrupt vector table is used to pass control to the
service routine of the interrupting device
- how control is returned to the interrupted program (RTI instruction)
BE ABLE TO:
- identify the different stages of interrupt processing in the
LC-3 state diagram (Figures C.2 and C.7)
- use the information in the LC-3 state diagram to explain what
happens during each stage of interrupt processing
Sample Exam Question:
List all information in the LC-3 that must be captured
in order to enable the interrupt routine to restore the state of the interrupted
program.