The reason I cannot give the exact value that is being returned is beacause it is very difficult to check it on my board. Let me explain. I am using this routine for a encoder measurement. I am simulatng the encoder pulse stream with a switch. The subtraction is a step to calculate the balance pulses. In the experimental set up I can calculate that the balance switch actuations should be eight to bring a counter to zero but even 100 to 200 switch actuations are also not zeroing my counter. This is only happening if the value to be subtracted is "all zero."

However I am immensly sure about the experience available on this forum. I have been able to solve many a silly doubts here. I will go back on Monday and recheck my code for any goofs.

thanks