3. (20 points) Write the COMPLETE main program and IRQ-ISR (IRQ Interrupt Service Routine) such that a) the main program will first initialize the hardware, and variables and registers (including the RESULT variable), then will continuously output the sequence $00, $FF, $00, $FF ... on port C. b) the IRQ-ISR will count the number of interrupts (i. e., the number of times the IRQ-ISR is called) and store the 16-bit count result in the RESULT variable. Assume that the external I/O hardware uses only the IRQ pin (assuming a level-sensitive IRQ) to synchronize with the processor. Also, make sure that the IRQ vector is set properly. It might be a good idea to simulate your program using Wookie (see the software tutorial on the course web page on how to simulate the I/O and interrupts). ORG $D000 RESULT RMB 2 PORTC EQU $1003 DDRC EQU $1007 ORG $C000