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Altera_Forum
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15 years ago

Unwanted offset attenuation in FIR filters

My FIR is now working so far - thanks to Altera Guru "MSchmitt" - but I still have two problems left. Please have a look at the attached pictures - there is an unwanted offset attenuation of 6dB in t...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

I agree, that some waveforms look strange. Unfortunately I don't see, how they are achieved.

I would expect this:

- all filter input/putput/external signals have a signed data type

- signed representation is also selected for simulation or SignalTap waveforms

- the filter input signal is (almost) DC free, in other words has 0 bias in signed representation