[sdiy] CPLD shield for arduino/AMANI 64/AMANI GT

Brock Russell brockr0 at shaw.ca
Tue Mar 27 21:00:42 CEST 2012 

I agree there is probably no need to design a modern TOG. As I said 
in my last post, while it's possible, it's probably not practical to 
make an MK50240 clone. For me, this has been a simple design exercise 
to learn the Silego design tools and see what the parts are capable 
of. Some people like to flash an LED on and off, I prefer to make 
sounds when I'm trying out a part for the first time. In this case, 
the basic counter/divider operation is a very small aspect of what 
the parts can do, but once I saw it was trivial to get four notes 
from a part and they are so crazy small I decided to see if it was 
possible to place all the parts required for TOG clone in a 16 pin 
DIP form factor and it was.

I'm not actually a fan of TOG instruments, I find they are noisy, 
mine certainly is and I've got an old Wurlitzer combo organ that's a 
wheezy thing too. I think the entire concept of a large number of 
oscillators always on is flawed, it just happens to be something 
really easy to design. You could put a dozen individual oscillators 
on a board but that's not really any different. My Wurlitzer uses a 
dozen LC oscillators.

These parts do operate fast though, about 100MHz internally at 5V. 
With a fast clock and a 14-bit counter I'm pretty sure you could tune 
these things to your satisfaction.

What am I going to do with these chips? I don't know. I'm an embedded 
system designer with a reputation for designing the micro out of 
small designs and that's exactly what Silego advertised these parts 
suitable for so that's the most likely use. But I'll probably make 
sound with it too. I just found the development board is limiting for 
prototyping, especially for battery powered designs which these parts 
seem ideally suited for, so that's why I decided to make a dip adapter.

Brock

At 03:09 AM 27/03/2012, Tom Wiltshire wrote:
>Whilst I applaud the effort and ingenuity that is going into these 
>attempts to build modern top-octave generators, I don't understand the need.
>The switch from separate master oscillators to one master osc and a 
>top-octave generator chip caused a notable flattening in the sound 
>of the instruments that did it, since everything got phase-locked together.
>Wouldn't we be better off putting twelve surface mount oscillators 
>on a chip? Or are you guys so far ahead of the original clock speed 
>that it stops being such an issue? What are you intending to do with 
>these chips? Just curious, not criticising.
>
>T.
>
>On 26 Mar 2012, at 23:23, Brock Russell wrote:
>
> > I see, you're not making an MK50240 clone exactly, but making a 
> usable top octave generator. That still seems to be quite a trick 
> to get the design done to that few cells. I've been thinking of 
> going in the opposite direction, using a higher frequency clock and 
> a ten bit counter, but the MK50240 type clones I designed use the 
> same divisors as the original.
> >
> > I haven't soldered the Green PAK2 DFNs. I haven't made any boards 
> yet as I can't make boards myself with toner transfer that have 
> 0.4mm pitch parts and I didn't really want to make some single 
> design boards. I finally decided over the weekend to make some DIP 
> adapter boards that have battery back up so I can prototype with a 
> bunch of devices without having to permanently program the OTP 
> parts. The Silego development kit is two parts, the socket board 
> plugs into the main board, so I'm making a different socket board 
> with a DIP ZIF socket to handle the adapter boards. I should have 
> that up and running in a couple of weeks.
> >
> > Brock
> >
> > At 10:12 AM 26/03/2012, nvawter at media.mit.edu wrote:
> >> Heya!!
> >>
> >> Glad you noticed- it took a lot of work.  49 was my estimate, but my
> >> first draft uses 56 of the cells.  Cutting it close!  It has not been
> >> simulated yet, because I need to learn how to simulate in Quartus.
> >> The two approaches I used are to compute the minimum accuracy needed
> >> and to organize the dividers into a tree of chains that have common
> >> divisors!
> >>
> >> hmm checking out Silego programmable parts now.  interesting.  some
> >> nifty analog components inside those little devices, including an ADC.
> >> They might not be so bad for DIY..  they have free development
> >> software for Win as well as OSX.  They also sell dev sockets.  And,
> >> they have lots of how-to videos and a $50 dev kit.  They haven have a
> >> design library for OrCad and Eagle!  Intriguing!
> >>
> >> Did you end up solder-mounting your Silego DFNs?
> >>
> >> Quoting Brock Russell <brockr0 at shaw.ca>:
> >>
> >>> I'm kind of late picking up this thread but I have to ask, how do
> >>> you create a top octave generator with only 49 cells in a CPLD? The
> >>> Altera EPM3046A has one flip-flop per macro cell so it seems to me
> >>> you'd need two of these devices to generate 12 notes.
> >>>
> >>> I designed a few MK50240 clones a few months ago using 3 and 4
> >>> Silego SLG46400 Green PAK2 devices and some CD4504 level shifters.
> >>> It's actually possible to make a DIP sized plug in replacement. The
> >>> Silego parts aren't really DIY friendly as they are 2.5mm square 12
> >>> pin DFNs, but they are very cool devices containing a ton of
> >>> features in a 28 cent part.
> >>>
> >>> Brock
> >>>
> >>>
> >>> At 08:27 AM 15/03/2012, nvawter at media.mit.edu wrote:
> >>>> Oh, heck yeah!
> >>>>
> >>>> My friend and I are currently obsessed with recreating chromatic clock
> >>>> divider chips.  I think a CPLD would be great for that.
> >>>>
> >>>> The Altera EPM5064 on that Arduino CPLD shield has 64 macrocells.  My
> >>>> estimate for a single octave MK50240 clone is about 49 cells.
> >>>>
> >>>> anyone have any other ideas for MK50240 clones that are 
> available in stock?
> >>>>
> >>>>
> >>>>
> >>>>
> >>>> Quoting dan snazelle <subjectivity at hotmail.com>:
> >>>>>
> >>>>> are there any SYNTH DIY uses for a CPLD/programmable logic?
> >>>>>
> >>>>>
> >>>>> http://majolsurf.net/wordpress/?page_id=368
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>> http://majolsurf.net/wordpress/?page_id=1663
> >>>>>
> >>>>>
> >>>>> _______________________________________________
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> >>>>
> >>>>
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> >>
> >
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