[sdiy] Function Generator ICs

David Betz dbetz at xlisper.com
Fri Sep 21 16:49:11 CEST 2007

> Which board do you have?  When I went to the page above, the page  
> was blank except
> for a title banner.

I think that must be because the link wrapped in your mail reader. I  
followed the link again and it worked for me. Try making your message  
viewing window bigger so the link doesn't wrap and try it again. My  
board is the Digilent Nexys board with the optional 1 million gate FPGA.

> There was a "products" link, so I clicked that and they show
> some 12 or so boards, I couldn't figure out which one you have.   
> I'd like to know
> exactly which FPGA you have so I can compare it's internal  
> features.  BTW, I don't
> totally understand the "gate count" thing, I have the "500K gate"  
> Spartan-3E
> (XC3S500E), oddly though, in my polysynth design, the ISE says the  
> design represents
> 1,290,000 "equivalent" gates...

I'll have to look to see what ISE says about my FPGA. By the way, I  
would have bought the one you bought but I already had this board  
when I started the project and I decided to see how far I could get.  
I like the USB connection to the PC that lets me easily read/write  
registers in my design. It makes debugging easier. I'll have to try  
adding your MIDI circuit next. Right now I'm sending everything over  
USB from the PC. That's okay for testing but not good if I ever get  
to the stage of having a playable synth. Then I'd like to be able to  
use it without a PC.

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