FIR filter coefficient scaling and downscaling

Hi Kaz,

Thanks for your reply.

The Fir compiler has floating point, fixed point and Integer coefficients. For the calculation in your previous post:

coeff = round(4096*coeff/sum(coeff));

should I be using the integer coefficients that are output to the text file by fir compiler when i generate the filter? or the fixed point coefficients?

I have tried to use coeff = (4096*coeff/sum(coeff)); without rounding with the integer coefficients. The sum of resultant coeffs is 4096. And then I copied these scaled coefficients into a text file and used Import coefficient of fir compiler.

The new Integer coefficients that the compiler generates are less than 12 bits but their sum is greater than 12 bits.

I am not sure how the hardware implementation works, but i assume it uses the integer coefficients, So for DC signal value the output will be equal to sum of integer coefficients which is greater than 12bits.

Is that true? Once again thanks for replying to my question.