[sdiy] Function Generator ICs

[Scott Gravenhorst]

"Michael O'Bannon" <mob at mindspring.com> wrote:
>
>> All of the software I'm using for development is free, that includes the code for
>> the 8 bit MCU itself.
>>   
>Scott,
>
>Could you recommend some hardware and software for those of us who would 
>like to get a taste of FPGA's for music applications?

My only experience is with Xilinx.  However, so far they rate very high in my opinion.  They
allow you to download all kinds of PDFs.  The software that compiles your design from Verilog or
VHDL to an FPGA programming file which updates the FPGA is free from their website
(www.xilinx.com), it's called WebPACK ISE.  The reason I chose Xilinx is that Jim Patchell gave
me a heads up on the development board I have (Xilinx Spartan-3E Starter Kit) and that the price
was $149 with lots of goodies (RAM, flash, LCD, rotary encoder, DAC, ADC, etc.) on the board as
well as a reasonably large FPGA.  Bang for the buck, it's great.  It's not an audio board - it's
a dev board.  It has a 12 bit DAC which works, but is a tad noisy due to a nonoptimal reference
circuit.  This can be fixed by adding your own DAC through a connector.  The on board DAC has
been good enough to get things done.  I do MIDI stuff, so I use only the DAC, not the ADC.  For
MIDI, you need an optoisolator and for the output you need a resistor and a cap.  So you don't
have to build very much to get started.  The only thing I'd really like to add is a 16 bit SPI DAC.

When I had to make the MCU based MIDI controller, I downloaded their PicoBlaze code, free on
their size.  All I had to write was the assembly code for the controller.  I find their
documentation to be very good, easy to follow.

Here's more:

http://www.xilinx.com/xlnx/xebiz/designResources/ip_product_details.jsp?key=HW-SPAR3E-SK-US-G&sGlobalNavPick=PRODUCTS&sSecondaryNavPick=BOARDS&sGlobalNavPick=PRODUCTS&sSecondaryNavPick=BOARDS

They also have a slightly more expensive Spartan-3A board with similar peripherals, the FPGA is
larger.  

Anyway, I have no connection with Xilinx, I just like the product.



-- ScottG

-------------------------------------------------------------

-- Scott Gravenhorst
-- GateMan I - Xilinx Spartan-3E Based MIDI Synthesizer
-- PolyDaWG/8 - 8 Voice FPGA Polyphonic MIDI Synthesizer
-- FatMan: home1.gte.net/res0658s/fatman/
-- NonFatMan: home1.gte.net/res0658s/electronics/
-- When the going gets tough, the tough use the command line.