[sdiy] Xilinx 3E board comments

[Chris Strellis]

Hi Jeff,

> Where is Chris Strellis?

Hello! :)

I'm busy writing high definition digital video firmware for Alteras in AHDL :-P

I'm mostly an Altera man although I used Xilinx Virtex II Pro XC2VP7 for a year. 5 channels of 1.5GHz high def video in and out simultaneously - what fun!

>  I'm looking at his neat
> little additive synth and I think it makes for an interesting
> comparison, ie: how powerful is this 3E starter kit compared to what
> he realized his synth with?

www.strellis.com/fpga.shtml

This Altera had 200k gates which was 93% filled by the design. Although monophonic is ran at about 5MHz.  The Fmax for the design was about 33MHz and so could have been 5 note polyphonic.  With a 500K Spartan 3E (assuming gate for gate) could be around 12 note polyphonic and with greater Fmax even more :)

Please remember that this synth was an "implementation only" of Sam Nobbs VHDL code which he made available for a while.  I slightly modified it to get more note range - that's all. I'm a victim of time pressure and distractions. I haven't taken it any further since last year :(

Cheers

Chris

www.strellis.com
www.voynich.co.uk
www.strellis.co.uk
www.chromic.co.uk
















  I'm also wondering about what Jim
> mentioned with using an external uC to control the FPGA, which
> presumably saves good amount of resources, perhaps even across
> multiple FPGA's (Can these things be daisy-chained?), at the expense
> of connecting the them all up.  Presumably the *blaze's are optimized
> to be integrated into the rest of the system (since, indeed, they are
> made from the same stuff).
> 
> What about storage controllers?  Just another perephial to connect up
> and code for?  I'm really getting some gears moving on making some
> type of 'sampler'.. I've got some designs that I've been sitting on
> for a couple years now because I just didn't have any idea where to
> begin (I couldn't keep interest in software versions).  I assume a
> sequencer would only occupy a trivial part of the system resources,
> perhaps living in the picoblaze itself.
> 
> I've read a few of the .pdf's at xilinx now, and I can see that there
> is a learning curve to their documentation (and where they keep their
> documentation).
> 
> Lastly I assume that once you have a finished design on a FPGA you
> would move on to another process that creates a commercial product
> from the design ie:  a NordLead may have been created using a FPGA,
> but there is not a FPGA in a NordLead.
> 
> Ok, one more:  In terms of processing power where do dsp chips fit in?
>  Would I be achieving a similar result using a uC and some DSP chips,
> given that I sacrifice a great deal of flexibilty?
> 
> 
> 
> ... and I'm still mulling this "sampling module" idea.  Not making an
> entire sampler to fit into a modular, just a sampling oscillator /
> phrase recorder connected up to the proper analog I/O to fit in with
> the rest of the system.   Oh yea.. might as well add granular
> capabilty to it.. and vectors... hell, why not wave sequencing..
> anything else?
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