Low Pass Filter

[Altera_Forum]

does anyone know how to build the LPF with the quartus II?? And is it possible to load in the FPGA DE1 Clyclone II EP2C20F484C7N 

 Regards, Clark

[Altera_Forum]

Hello Clark,  

 you should know what kind of LPF you need, respectively at least part of the intended characteristics, e. g. fc/fs (cut-off frequency/ sample rate), stop band attentuation or equivalent analog filter prototypes (butterworth, chebyshev, elliptical filters of nth order). Personally, I'm often using simple first oder LPF, box-car integrators or CIC decimation filters in signal processing.  Naturally, hundreds of books have been written about digital filters.   Best regards,  Frank

[Altera_Forum]

I know the specification of my low pass filter . I just wonder if anyone know how to build the filter in the quartus II. I searched in the help of quartus II but can not find information about the filter.

[Altera_Forum]

Hello Clark, 

 for the Quartus software, filters are a DSP application among others. An IIR filter e. g. is just a few lines of HDL code, some constants, registers, mutipliers and adders. Additionally, Altera supports certain filter types with IP cores (Megafunctions): FIR filter, CIC decimation and interpolation, and applicaton specific filters, e. g. for video processing. But you may also use open cores from the internet, HDL code examples usually given in digital filter textbooks or code generated by particular filter tools as well.  Regards,  Frank

[Altera_Forum]

Dear Frank. I now build CIC the filter with D 79 according to the "Understanding cascaded integrator-comb filters" By Richard Lyons 

(see http://www.embedded.com/columns/showarticle.jhtml?articleid=160400592) What complexities can arise at filter construction? Regards Michael