Re: [oc] Audio synthesis core

[Rudolf Usselmann <rudi@asics.ws>]

on 6/17/01 7:29, Miggsy Fox at miggs_ectomorph@yahoo.com wrote:

> Hi OC People
> 
> Just started writing the multiplier for my audio
> synthesis OC project. Basically, it's a sort of
> wave-table like synthesiser, but with some advanced
> filtering and modulation synthesis. I figure that
> perhaps the general purpose MAC core might actually
> form a building block for the audio synth. However, I
> might discover that there are some mods to the MAC
> core that make it functionally rather different,
> therefore I am starting with a new multiplier. I am
> thinking of incorporating the accumulator into the
> multiplier structure somehow to reduce prop delays. Do
> have a quite efficient structure worked out for a
> 4-bit version. That's obviously just a starting point!
> Do people recommend that I start learning VHDL or
> Verilog first? Have only really scratched the surface

I believe Verilog is easier to learn and get started with.

> with these tools. I know that someone mentioned the
> DesignWare multiplier in the Synopsys tools, can
> anyone comment on the suitability of that multiplier,
> bearing in mind that I only need a fixed-point
> version?

I would not recommend using the DesignWare multipliers, as the
DesignWare library is part of a very expensive synthesis tool
and not everybody would have access to it.

> I will draw up a high level functional block diagram.
> I am toying with the idea at the moment of working out
> a direct interface to the RISC cores in OC. That might
> be a serial link to a serial I/O on the RISC core.
> Failing that it can always be memory-mapped I/O. That
> will allow driver coders to get access to the audio
> that is produced by the synth core, and thus do
> further useful things with it in software, but these
> are issues in which people might want to be involved.
> I will probably put most of the audio modulation in
> the synth core itself, thereby allowing it to be very
> largely stand-alone.

I think it would be better to have a WISHBONE interface.
This would ease the movement of data between your synthesizer
and for example my AC97 core. We have decided a while back
to adopt WISHBONE as the "standard" interconnect for all OC
cores. It's not a must, but if you have to make a choice, than
rather make it compatible with other OC cores. The RISC will
also have a WISHBONE interface.

> BTW, can anyone tell me how to get the audio synth
> core listed on the projects page?
> 
> Thanks
> Miggs

Cheers !
-- 
rudi


--
To unsubscribe from cores mailing list please visit http://www.opencores.org/mailinglists.shtml