Hello, I am fairly new to assembly language and using Dspic's. The following is a program that I have been working at for quite awhile. I am using DsPic33fj64gp802. "Write a program for timer, the timer is working as counting mode, and its main subroutine will display its counted value on PORTB. Every 5 pulse from outside, it will trigger the timer interrupt, then its interrupt subroutine will toggle PORTA.0 five times" I am unsure how to implement the interrupt on the 5th pulse from the outside. At the moment I am trying to use timer1 as an Asynchronous counter, which the interupt will toggle PORTA.0 five times.. Any help or suggestions would be appreciated. Thank you.