[postgraduate entrance examination] group planning: interrupted

One 、 Classification of interruptions

 

Two 、 Interrupt processing

（ One ） Nested interrupt handling procedures

1. Close the interrupt ;

2. Save breakpoints （PC）;（ Breakpoints can be pushed onto the stack , It can also be stored in a specific unit of main memory ）

3. Interrupt service program addressing ;

4. Save site and screen words ;

5. Open the interrupt ;

6. Execute interrupt service procedure ;（ The purpose of the interrupt request ）

7. Close the interrupt ;（ Guarantee No. 8 Step not interrupted ） 

8.  Restore the scene and shield words ;（ Restore the scene ： Before the interrupt returns , The contents of the register must be restored to the state before interrupt processing ）

9. Open the interrupt ;

10. Interrupt return .（ Usually return to the breakpoint of the original program ）

Be careful ：

（1）1. 2. 3. It's done by hardware , Interrupt the operation completed by the implicit instruction ; The rest is interrupted by the program （ Software ） complete .

（2） Multiple interrupt shielding technology is mainly used for multiple interrupts .

May refer to ： Interrupt shielding technology _dongyanxia1000 The column -CSDN Blog

（ Two ） Single stage （ Or single weight ） Interrupt the system （ Don't allow Break nesting ）

1. Close the interrupt ;

2. Save breakpoints ;

3. Identify interrupt sources ;

4. Save the scene ;

5. Interrupt event handling ;

6. Restore the scene ;

7. Open the interrupt ;

8. Interrupt return .