08-05-2019 01:29 PM - edited 08-05-2019 01:49 PM
can someone help me to get out of this situation, I am trying to get several analog signals and filter them using XADC and FIR compiler, in the following pictures there is the design and waveforms that I am getting. I configure FIR compiler to filter in multichannel mode, I don't know where the problem but the outputs aren't what I am expecting
08-05-2019 06:36 PM
Looks like a classic signed as unsigned problem. Did you select radix as unsigned or signed in the waveform viewer? (Select wave, right click -> radix->signed decimal). You still have to do the analog settings as usual. I also recommend waveform style->Analog settings->Interpolation style-> o Hold (instead of linear)
08-05-2019 11:48 PM
I did exactly what you told me, but the filter that i am using is a pass-low one as you can see on response picture. so from every input, I should get just the first harmonic (50hz). i think it works on the last signal vaux2 but not on others.
please what do you wanna say by this ('Adaptable Processing coming to an IP address near you.')
08-06-2019 07:07 AM - edited 08-06-2019 07:09 AM
Your vaux1[13:0] looks better.
Are you scaling correctly? (Looks like you're clipping).
I like to normalize my coefficients between [-1.0, 1.0) -- signed fractional. How big are your coefficients? Looks like 16 bits with 18 fractional bits. I am not sure what that means, but it might mean your coefficients are scaled between [-0.25, 0.25), or it might be nonesense. If you have 16 bit coefficients, try 15 fractional bits. You may have to recompute your coefficients.
Do an FFT and plot phase/magnitude versus frequency and verify your frequency response.