Just a short note:
The averaged output generated by the posted code is formed from eight added
positions, then just shifted right 3 steps to divide by 8.

This truncates, giving a rounding error of a half lsb average.

Remedy is of course to initialise the 3-byte adder T4:T3:T2 to 000004
instead of clearing it as now is done in routine Sum16.

/Morgan
        Morgan Olsson                   ph  +46(0)414 70741
        MORGANS REGLERTEKNIK            fax +46(0)414 70331
        H€LLEKS           (in A-Z letters: "HALLEKAS")
        SE-277 35 KIVIK, SWEDEN               mrt@iname.com
___________________________________________________________