Dear Abdul Rauf

As salam alaikum,

I'd like to help you very much, but I have to leave immediately.

For short info; you can produce an accurate pulse width but first you have to consider the tech. specs. of IR transmitter and receiver which you use.
Read the data sheets. And I have to know the crystal freq. to help you.

I'll try to help you more as soon as possible.

Wassalam,

Selim Dilmac