I enjoyed working with Hans at hardhack this year on the Rekonstrukt project to build a basic synthisizer in an FPGA. LED projects are also good but there is nothing like plugging up the FPGA to a stereo. It isn't building from the ground up, as an LED project would, because the project is based on a open core processor that supports forth. So at the beginning you are learning how to basically load the FPGA with the project, then you can play with the envelopes in FORTH. But where you start to learn more about the FPGA internals is when you want to add functionality, which then requires digging into the VHDL.

Hi! You should check out opencores.org and find an interesting project there. You can also download the Sigasi HDT, which will help you up to speed on VHDL grammar.

Since you seem interested in programming you could build a simple microprocessor.

I wrote vhdl code for xilinx virtex core sometime ago. it was an alarm clock implementation. This is what i did:

• Read a lot through vhdl manual - i'd have to revise on it now but i found it pretty straightforward and easy to use hdl :-)
• Used xilinx suite (compiler, synthesizer) to get the bitstream
• Uploaded the bitstreams using jtag

Rinsed, Repeated 1-3. I'd point out that bitstream generation is very much all integrated in Xilinx's IDE. You just have to have clear set of logic to implement in HDL; all the rest of the stuffs are done by the IDE.

A project that I enjoyed doing was implementing the Milton Bradley Simon Game on a FPGA.

At my university, our EDA class uses the same board you mention. Some of the projects implemented included:

• Image processing: median filter, histogram stretching, edge detection
• Cryptography: AES, various hashing algorithms, etc.
• Communication: Ethernet, USB, I2C, etc.
• Games: Pong, space invaders, etc.

That may give you some ideas.

I'll second the opencores.org idea as well as implementing your own microprocessor. Since you have a Xilinx FPGA, you might also look at doing something with microblaze or picoblaze.

Edit: formatting.

Numerically Controlled Oscillator would be fun. I just did a design with my Arduino compatible board (see http://tinyurl.com/ydmz2su) but this would be perfect for an FPGA.

Here are a couple of design references.

Snell, John 1988 "Design of a Digital Oscillator That Will Generate up to 256 Low-Distortion Sine Waves in Real Time" Foundations of Computer Music. Cambridge, Mass.: MIT Press

Moore, F. Richard 1988 "Table Lookup Noise for Sinusoidal Digital Oscillators" Foundations of Computer Music. Cambridge, Mass.: MIT Press

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