[sdiy] TI DSPs open source compiler?

[Jay Schwichtenberg]

Here are some rantings of a deranged HW/SW engineer which are not to humble
and very opinionated.

I've had one real bad experience with TI DSPs on a project and friend has
had another. So I'm not hot on them. Also a lot of TI DSPs only come in BGA
(Ball Grid Arrays). I'd stay away from this type of package if you're doing
this as a home project or as a small production run. These packages are hard
to remove without special tools, you'll probably have to have a multi-layer
board to get to all the pads and it's difficult to trouble shoot with out
bringing all the pins out to vias. If you look at most digital audio based
boxes they mainly use either Motorola or AD Sharcs. 5 years ago I know that
people had problems with getting the Motorola 56301 working on the PCI bus
but they eventually got it to work. A few of Mackie's digital audio items
actually have embedded PCs in them.

I don't know what the internal memory of the chip is but I dough that it has
enough for handling audio data. So you'll probably have to add some memory
on the outside. Figure out what the longest delay line you'll want is (maybe
2 to 4 seconds), take sample rate, sample depth and number of channels then
figure out what you need. If you want multi-effects then add even more
memory. Dynamic memory is a good way to get lots of memory cheap. Look for a
DSP that has a built in dynamic memory controller.

Alesis converters are not multi-bit and don't take standard I2S. All audio
targeted DSPs have the I2S interface. You need to check to see if the timing
from the DSP word clock and data will work with Alesis converters if you use
them. One pet peeve of mine is that people spend all the money on the
digital stuff and little on the analog. In most cases I'd rather have a
couple of SPDIF interfaces I could use what I want for converters. Put in
good prosumer multi-bit converters, good op-amps and components and a real
good power supply (78XX/79XX/317/337 3 tabs don't hack it at the high end).

Also before you really get into look to see if other DSP products will work
for you. It's a major project and in the long run it will be cheaper to buy
something already built if you consider your time worth anything. Check out
Creamware, Soundart Chameleon and others. If your a Mac user running system
9 and have a full length PCI slot maybe a Korg Oasys with their SynthKit
software. There are two Yahoo discussion groups for the Qasys and you'll
have to sign a NDA  (Non-Discloser Agreement) with Korg to get SynthKit.
These are obsolete, there will never be OS X or XP drivers for them, so you
can probably pick them up cheap on e-bay. I got mine when Guitar Center was
blowing them out cheap and keep an old Mac just to run the SynthKit. Haven't
done anything with SynthKit yet but the Oasys has some nice synths and
effects, ADAT, SPDIF and stereo analog IO.

If you want to get a good idea on what it takes code wise to do signal
processing get access to a computer with a development system. Then try
writing some plug ins for VST, DirectX or whatever you use. Most info is out
there to do this for free but you may have to request it or sign a NDA.
Basically if you can't code a plug in you probably won't be able to write a
real time OS and do signal processing on it.

Happy coding.
Jay

> -----Original Message-----
> From: owner-synth-diy at dropmix.xs4all.nl
> [mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of
> cris at music-service.nl
> Sent: Thursday, July 24, 2003 8:15 AM
> To: synth-diy at dropmix.xs4all.nl
> Subject: Re: [sdiy] TI DSPs open source compiler?
>
>
> I was thinking to use the TI DSP TMS320C6713 in combination with
> the Alesis
> ADC/DAC
>  http://www.alesis-semi.com/index.html
> I want to use externally only one serial flash IC about 16MB (ST) and i
> don't know if is possible to make the system work.
> But i don't know jet, Motorola and AD have good DSP's too......
>
>
> > DSP chip may cost only 7$, but what is the value of time
> > you'll spend making any proto board with it?
> > It has lots of pins, the DAC requires some extra components and proper
> layout, loading firmware can be tricky, etc.
> > If you spend a little extra, you'll get nicely made board with ACD, DAC,
> PC interface, buttons, leds, headers etc, plus all basic
> development tools,
> sometimes including C. And, of course, firmware examples to play with.
> >
> > As I recal, floating point DSP starter kit from TI was the
> cheapest of all
> fl-pt. DSPs at its time, and fixed was even cheaper.
> > I checked TI website. Ususal price for starter kit is now 400$. Sad.
> > But OTOH it's for powerfull 6000 family too. You should be able to find
> second hand old TI starter kits with TMS320C54 and C32 on ebay or whatever
> for less than 100$.
> >
> > Roman
> >
> > ---- Wiadomość Oryginalna ----
> > Od: Bert Schiettecatte
> > Do: synth-diy at dropmix.xs4all.nl
> > Data: Mon, 21 Jul 2003 18:59:27 +0200
> > Temat: [sdiy] TI DSPs open source compiler?
> >
> >
> > Hi all,
> >
> > Just wondering: are there open source compilers available for
> TI DSPs ? Or
> is there a way to get a C/C++ compiler from TI that is not
> limited somehow?
> I?m thinking about doing a project around one of those cheap 7$
> fixed point
> DSPs from TI. I found a 24-bit DAC from TI too that has a I2S
> interface but
> no clue how to interface that to the McBSP port of the DSP (yet). You have
> guessed it by now: I am completely clueless about TI DSP development.
> >
> > Any suggestions welcome !
> >
> > bert
> >
> >
> >