[sdiy] Using analog for physical modeling

[Matthew Smith]

Quoth Eric Brombaugh at 22/09/11 07:25...
...
> I've been using the 200kgate version in a VQ100 pkg. Available from
> Digi-Key for ~$13 in single qty. That's about 1/2 what Element14 charges
> for the BGA version of the 200kgate parts.

Pity about the $64 freight charge :-/ Digikey and Mouser present 
themselves as having "presence" in Australia - unfortunately this isn't 
reflected in their freight pricing. (Element14 doesn't charge me freight 
at all.) At that rate, it's cheaper for me by far to use Spartan 3E with 
external configuration memory - as I could do about two and a half of 
these just for the Digikey freight price!

> The 50k part can probably do a fair amount of stuff though. I've found
> that my simpler designs are only taking about 25% of the resources in
> the 200k parts.

Cool - I'll see what I can squeeze in there.

> A good audio codec has high resolution (16 - 24 bits) for good SNR, high
> sample rates (even most cheap ones will do 96kHz) and all the
> anti-aliasing filtering built in. It will usually also have some handy
> routing and mixing functions. And they're dirt-cheap (think in the $4
> range). Only downside is that you have to figure out how to implement an
> I2S interface in your FPGA, but that's easy (I've got some sample code
> on my website).

OK, thanks - sounds like the way to go. I also haven't had anything to 
do with I2S, so now sounds like a good time to learn.


-- 
Matthew Smith

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