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Altera_Forum
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15 years ago

FIR filter coefficient scaling and downscaling

I have a sensor signal which is unsigned 12 bits and i need to filter the signal using a FIR filter. The filtered output feeds into an algorithm which expects 12bit unsigned input. I have used...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

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The sum of coeff is 51519. Do you think some thing is not set right in the fir compiler setting.

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I guess it's normal operation of the FIR compiler, but it ends up in a DC gain that's not a power of two, so you can't get a gain of 1 by just adjusting the number of bits. Provided, that the coefficients are now using the full range, you can use manual scaling to the next smaller power of two, 32768.