Written by Tom on Monday 09/04/07
This is a simple 4 tap FIR. This is a dedicated filter. A general purpose filter will be worked on later.
I don’t know a lot about DSP so just got the example from "Circuit Design with VHDL" by Volnei A. Pedroni, working with GHDL.
The basic formula is below.
y(n) = c0x(n) + c1x(n-1)+...+ckx(n-k)
And can be expressed as
y(n) = m(sigma)k=0 ckx(n-k)
y(n) is the output for n
m is the number of coef/Taps in this case it should be m-1 as the arrays are index from 0
k is the index to start from
c is the array of coef
x(n-k) is the input for n
The above formula was implemented in this project.
Download the project from here.
GTKWaveSignals.jpg contains the simulated signals.
Use the go.bat to compile and run GTKWave.