Hi Waqar
You never give up do you ?
If you want to eat an elephant you cut it down to small pieces so that you can eat it.
With your pulse dialing intercomes do the same, cut your project into small little projects you can do and add them all together to make your final product.
You have to make your code modular so that you can test each module on its own and make sure it is working then add all your modules together to make your final working software.
Have you done one channel pulse decoding? if not I suggest you start counting one channel pulse decoding and make sure it is working before you attempt to do the 8 channels at the same time.
I think if you get the code served on a platter you will never learn anything so what you should do is think about it yourself and ask about better ways of doing it.
If you ask specific questions people would help you better than asking them to teach you microcontroller design and programming.
After all this is a specialisation topic, if you are so interested in microcontroller design why did you study architecture? why waste your time learning one career and switching into a complicated subject like microcontroller design. Look how much time you wasted in your life. The human brains is like a pot and when it is full it can take no more.
So I suggest for your pulse dial decoding do the following:
1. Learn how to measure the width of one pulse.
2. make a time window starting from the time of arival of rising edge of first pulse.
3. count the pulses in the time window
4. When you do it for one digit, think about other ways to decode 2 or 3 digits before you set a flag or take action.
5. once you produced working code for one channel start thinking about decoding 8 channels at the same time.
Regards
Mahmood