The Digital Synthesizer Module Number One

First Posted July 16, 2005

    I am not sure exactly what form this project is going to take yet.  My original concept was to make an addon board for the Xilinx Spartan 3 Starter Kit.  The Starter Kit board has an XC3S200 part on it.  It appears that maybe this board is just a little bit too small.  The 200K gate part is just not going to be able to do all I want it to do.  It would seem that I will need to use at the very least the XC3S400 part.  But I am not giving up yet.

You may ask why I am using Xilinx.  Well, the biggest reason is that Xilinx seems to be just a little less expensive to play with.  I have nothing against the Altera parts.  And you can probably apply what I hope will soon be posted here to those parts.  As soon as I can locate a Cyclone II eval board that I like, I will probably dive into that part as well.

You may also ask why an FPGA?  Why don't you use a DSP like Clavia does for the Nord Modular?  The answer to that is I think the FPGA will be more fun.  Also, the FPGA has a lot of raw horse power that is going to be difficult to achive even with the fastest DSPs.

What are my goals?

    Right now it is to create a set of hardware that I can easily experiment with producing digitaly created sounds.  Some of the basic functions that will need to be created will be Oscilator banks, Filter banks and envelope generator banks.  These are probably the most difficult functions to do.  One thing I don't know how to do at the moment is to create a way that modules can easily be interconnected.  However, creating large quantities of the above elements is going to be relatively easy.  Creating 512 32bit oscillators should be a piece of cake.  Doing on the order of 128 filters should also be fairly easy.