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Altera_Forum
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16 years ago

Pre-Emphasis with IIR Filter

Hello! I want to do a classic Pre-Emphasis with VHDL. Normally this is implemented with an IIR-Filter. I tried to do this in VHDL with the following formula I found in the web: y(i)=x(i)-(x(i-1...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

here is my first go: 


elsif (clk'event AND clk = '1') then
 
X <= Input;
Yn_tmp := Xi1 * b0_var;
Yn_tmp2 := Yn_tmp / div;
Yn := resize(Xi, Yn_tmp2'length) - Yn_tmp2;
 
Output <= resize(Yn, Output'length);
Xi1 := resize(Yn, Xi1'length); 
Xi := X; 
 
end if;

note that Yn relates to Xi and Yn_tmp2

yet Yn_tmp2 relates to Xi1

Xi and Xi1 are same stage values.(only x is delayed at x <= input))