electro-music.com   Dedicated to experimental electro-acoustic
and electronic music
 
    Front Page  |  Articles  |  Radio
 |  Media  |  Forum  |  Wiki  |  Links  |  Store
Forum with support of Syndicator RSS
 FAQFAQ   CalendarCalendar   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   LinksLinks
 RegisterRegister   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in  Chat RoomChat Room 
Live streaming at radio.electro-music.com

  host / artist show at your time

poster

Please visit the chat
 Forum index » DIY Hardware and Software » Microcontrollers and Programmable Logic
Programmable Logic as Equal-Temperament generator
Post new topic   Reply to topic Moderators: State Machine
Page 1 of 1 [7 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
Tony Deff



Joined: May 25, 2008
Posts: 51
Location: Suffolk, UK

PostPosted: Sun Mar 22, 2009 11:21 am    Post subject: Programmable Logic as Equal-Temperament generator
Subject description: Suitable Devices (if any)
Reply with quote  Mark this post and the followings unread

Since the demise of 16-pin Top-Octave Generators (TOGs) [or Top-Octave Synthesizer (TOS) in the USA — as though it were inferior to a real top-octave], many people have been nostalgically looking to re-create these within programmable logic or micro-controllers, and such wishful thinking can out-weigh real appreciation of the limitation of these devices.

Inevitably, the PIC series has been the subject of such debate, and intrigued by a claim that can be found on the web, I took a look at how an entire top-octave could possibly be output from the humble PIC. (See the thread in the Developer's Corner from last year).

When it comes to programmable logic, the Amateur faces the problems of acquiring suitable devices and the mountainous obstacle of programming the damn things. Programming algorithms are usually protected by the Official Secrets Act, and we can all guess the reasons behind (preventing the runaway success of a device by hoards of amateurs buying it, and somehow upsetting the market?)

Nobody wants to be abducted in the middle of the night through Extraordinary Rendition for having cracked the 22V10 algorithm.

But we need far greater resources than the 10 miserly flops of a 22V10. Twelve divisor outputs of 10 or 11-bit counters require some 120+ flops.

What devices are available to the amateur, have solderable pins, can be programmed by a home-built, or affordable, programmer and have more resources?

A medium-size programmable-array may suffice if they could be used in parallel. For example, suppose we could implement a 1-of-12 divider via a binary select code, so that a multiplexed system used just as many note-selectors as required, or if a similar single-note generator could be cascaded so that each generator produced the next semitone, and the whole set could be transposed?

Many years ago, when bored at work, I wrote a PALSAM code that generated 1-of-16 semitones using a 22V10. It was written especially considering the device's limitations (which involves unorthodox approach, minimization and pin-juggling), but I did it. (At least theoretically: it compiled without error, but I was never able to burn a device and try it).
Back to top
View user's profile Send private message
JovianPyx



Joined: Nov 20, 2007
Posts: 1726
Location: West Red Spot, Jupiter
Audio files: 195

PostPosted: Sun Mar 22, 2009 12:35 pm    Post subject: Reply with quote  Mark this post and the followings unread

Someone on Synth-DIY (email list) is making a TOG using a PIC. Not sure which model, but he's making them available. I think it is Tom Wiltshire, but I'm not sure. You can sub to the list if you're not already subbed and just ask the question there. Getting one of his units takes all the nasty programming bother out of it, assuming they are not all spoken for.

I hope this helps.

_________________
FPGA, dsPIC and Fatman Synth Stuff

Time flies like a banana.
Fruit flies when you're having fun.
BTW, Do these genes make my ass look fat?
corruptio optimi pessima
Back to top
View user's profile Send private message Visit poster's website
yerpa58



Joined: Mar 08, 2008
Posts: 57
Location: Wisconsin
Audio files: 4

PostPosted: Tue Mar 24, 2009 9:22 am    Post subject: Reply with quote  Mark this post and the followings unread

This subject has come up before:
http://electro-music.com/forum/post-188525.html

I can program PIC 16C54 chips from OldCrow's "oct54all.asm" code if anybody is interested, but there are also plenty of cheap PIC programmers out there.
Back to top
View user's profile Send private message Visit poster's website
skrasms



Joined: Feb 21, 2008
Posts: 121
Location: Portland, OR

PostPosted: Tue Apr 07, 2009 5:49 pm    Post subject: Re: Programmable Logic as Equal-Temperament generator
Subject description: Suitable Devices (if any)
Reply with quote  Mark this post and the followings unread

Tone-Deaf wrote:

What devices are available to the amateur, have solderable pins, can be programmed by a home-built, or affordable, programmer and have more resources?


Altera has some really nice CPLDs in the one to two dollar range (through digikey) with 32 and 64 macrocells. I don't recall what that works out to in terms of actual usable gates, but it's a lot nicer than a 22V10. The only catch is that you have to buy PLCC adapters to give them solderable pins. It adds about $1 per chip.

Altera's programmer is prohibitively expensive, but Terasic and others make knockoff programmers for $150 and under. The software is free.

Look up the MAX3000 series if you're interested.

_________________
Software and Hardware Design
Back to top
View user's profile Send private message
slabman



Joined: Sep 01, 2005
Posts: 102
Location: UK

PostPosted: Fri Apr 17, 2009 7:42 am    Post subject: Silicon Labs Si5334 Reply with quote  Mark this post and the followings unread

I just came across this - it could be a contender: https://www.silabs.com/products/clocksoscillators/anyrategeneratorsandbuffers/Pages/default.aspx

Quote:

The Si5334/38 any-rate, any-output quad clock generators are high performance, low jitter clock generators capable of synthesizing any frequency on each of the device’s four differential outputs. ... Each output clock can be individually programmed to generate any frequency from 0.16 to 350 MHz and select frequencies to 710 MHz at very low jitter (1 ps rms typical random jitter) and zero ppm frequency error.

End quote.

3 of those gives you an octave
Back to top
View user's profile Send private message
urbanscallywag



Joined: Nov 30, 2007
Posts: 317
Location: sometimes

PostPosted: Fri Apr 17, 2009 11:07 pm    Post subject: Re: Programmable Logic as Equal-Temperament generator
Subject description: Suitable Devices (if any)
Reply with quote  Mark this post and the followings unread

skrasms wrote:
Tone-Deaf wrote:

What devices are available to the amateur, have solderable pins, can be programmed by a home-built, or affordable, programmer and have more resources?


Altera has some really nice CPLDs in the one to two dollar range (through digikey) with 32 and 64 macrocells. I don't recall what that works out to in terms of actual usable gates, but it's a lot nicer than a 22V10. The only catch is that you have to buy PLCC adapters to give them solderable pins. It adds about $1 per chip.

Altera's programmer is prohibitively expensive, but Terasic and others make knockoff programmers for $150 and under. The software is free.

Look up the MAX3000 series if you're interested.

Gates don't really matter in this case, its number of flip flops (which is equal to the number of Marocells).

If you're going Altera the smallest MAX II CPLD has 240 LEs, easily enough for a TOG. Cost is ~$6 in quantity 1, but it does have an on board oscillator that I think would work in this application.

There are knockoff programmers on eBay in the $30 range. A friend has the tiny one that looks like a thumb drive, it works well so far.
Back to top
View user's profile Send private message
Gordon2



Joined: Apr 13, 2017
Posts: 2
Location: Ulm, Germany

PostPosted: Thu Apr 13, 2017 8:06 am    Post subject: Reply with quote  Mark this post and the followings unread

It's quite easy to use a very cheap chinese altera CPLD board (eg EPM1270t144) to make a top octave generator. In fact you can get most of the lower octaves as well from one board, even all free phase if you want. The biggest difficulty is getting your head around the (free) 2GB Quartus II software for programming. I use schematic entry as opposed to Verilog or VHDL entry.
You don't even need to use optimised divider ratios as the clock frequency is so high - 48MHz - that practically any ratios are accurate enough (ie accuracy better than 1 cent). The main limitation is the number of I/P and O/P pins. Would be great if a midi decoder could be included in the design - a bit beyond me!
Gordon Nudd
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic Moderators: State Machine
Page 1 of 1 [7 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
 Forum index » DIY Hardware and Software » Microcontrollers and Programmable Logic
Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
e-m mkii

Please support our site. If you click through and buy from
our affiliate partners, we earn a small commission.


Forum with support of Syndicator RSS
Powered by phpBB © 2001, 2005 phpBB Group
Copyright © 2003 through 2009 by electro-music.com - Conditions Of Use