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Honored Contributor
Honored ContributorIIR audio filter problem
Hi, I'm trying to make a IIR lowpass filter in VHDL. i used matlab to design the filter, tested it in simulink and it seemed to work. I also used matlab to generate vhdl code (using filterbuild...
Altera_ForumHonored Contributor
Honored ContributorI'm not aware of any VHDL syntehsis tool supporting the real variable for signals. It's an abstract data type available for simulation and compile time calculations, that can be used e.g. in constants. But for filters implemented in FPGA, you have to use synthesizable types. Under special circumstances, IEEE float or double can be be synthesized, but real can't. Most designers are using fixed point arithmetic for it.
For a profound introduction to filters and digital signal processing, I suggest U. Meyer-Baese "DSP with FPGA".
