Goal: To become familiar with using XIRQ hardware interrupt, writing your own interrupt service routines, setting up interrupt service routines and using Dragon12-Light boards, and improving your programming skills.

Project:

1. Please read section 11.3 of your textbook, or Lecture 8 on IRQ and XIRQ interrupts. Then, study this example program, LEDsByIRQ.txt.
   Assemble, download, and test the program. Please understand the entire program completely.
   
   
2. To enable XIRQ interrupt, modify the main program: replace the codes for enabling IRQ interrupt by code
   to enable XIRQ interrupt.
   
   
3. Change the service routine name from IRQ_ISR to XIRQ_ISR.
   
   
4. Set up your XIRQ interrupt vector accordingly.
   
   
5. Modify the XIRQ_ISR service routine to do the following:
   a) When a momentary active-low signal is sent to XIRQ pin, it generates XIRQ interrupt. Your XIRQ interrupt service routine will be called, which turns on all the even LEDs.
   
   b) Let them stay on for one second by calling a one second delay subroutine.
   
   c) After finishing handling the interrupts, the main program should just turn off all LEDs.
   
   d) When another momentary active-low signal is sent to XIRQ pin, it generates XIRQ interrupt again. Your XIRQ interrupt service routine will be called, which should turn on all the odd LEDs.
   
   e) Let them stay on for one second by calling the same delay subroutine.
   
   f) After finishing handling the interrupts, the main program should just turn off all LEDs.
   
   g) If active-low signal is provided continuously at XIRQ pin, then your XIRQ service routine should continuously toggle even/odd LEDs in one Hz frequency.
   
   
6. After finishing handling the interrupts, the main program should just turn off all LEDs.

 

What help do you need?

 

Have you read the chapter and studied the example yet? You should be able to do that much without help.

Bob