I build a measuring device, which counts the number of pulses in a given
time.
Unfortunately the fluctuation of the measured values is so big that a
single measurement is not very informative.
So I would like to implement a running average algorithm, which gives
the average of the last eight values.
It should add up the last eight values and divide then by 8.
but my values can be everything between 256 and 0. If I divide every
value before adding them up I get very arbitrary averages from low input
numbers due to rounding errors.
Is there a possibility to do 16 bit integer arithmetric with two data
registers.
I  think about putting the carry bit of a addition into the second
register... All code I made myself by now seems to be very complicated
and awkward. Perhaps someone has a more elagant solution for this?

Thanks in Advance
Cheers Ralf