[Fpga-synth] Simple Filter Question

[Nicholas Gregorich]

On Jun 20, 2007, at 8:25 AM, Scott Gravenhorst wrote:

> "The making of synthesizers in FPGAs." wrote:
>> Looks like you got some help on this already, but here's my MATLAB
>> work on it anyhow. :)
>>
>> http://homepage.mac.com/nicksdsu/fpga-synth/terrormouse_iir.pdf
>>
>> Nick.
>
> Hi Nick,
>
> Very nice, how did you get the z-plane pole/zero plot?  I use have  
> no access to
> MATLAB, but this seems simple enough that it should be implemented  
> in the most
> recent Octave release - can you tell me the name of the function/ 
> command?  Part of
> my problem is that I am completely ignorant of many terms taught in  
> college courses
> for DSP, so I don't even know what terms to search on yet.
>
> Thanks for your help.
>
> -- ScottG

Hey Scott.

That pole zero plot was actually from an m-file I made. I use zero()  
and pole() to find the poles and zeros of the transfer function then  
actually draw a unit circuit and plot the individual poles and zeros.

The MATLAB command is "pzmap(h)" to do the same. I use my own m-file  
to tailor to suit my needs, for example comparing quantized and non- 
quantized filter coefficients.

Nick.