5/1usec=5000000 or 5X10^6 now factorize it. Since an 8-bit register can hold decimal value=255 but just to keep our calculations simple I will choose the factor of 250. So, 5000000/250=20000 now factorize 20000=200X100 hence 200X100X250=5000000 So, you will set three counts like count1=250 count2=200 count3=100 and then use the nested looping just like I have mentioned for introducing the time delay. BTW I have assumed crystal frequency of 4MHz in this case. You can do calculations for any crystal frequency.
