FIR Compiler II fractional signed fractional binary (integer bits output width)

Hi vanoDNK!

I'm your mirror copy from future!

The answer is something like that:

If the Fractional bit width of coefficients is 1, when you see in the fixed point value of fir compiler II "1", it is actually 0.5 (decimal), if you select the coefficient fractional bit width as 2 bits, then the fixed point value became "3" (decimal), and it is actually 0.75 (0.5 + 0.25). So the filter output gain tend to be a sum of coeffs with the rsie of coeff bit width number. And if you select Fractional bit width of coeffs as "1", than filter output gain will be only a half of number of coeffs (true if all coeffs are equal as for moving average filter).