No more discrete digital logic for me?

Discussion in 'General Electronics Chat' started by t06afre, Mar 24, 2011.

  1. t06afre

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    I have a wet dream to quit using TTL circuits in my hobby project and move to CPLD instead. Has any in this forum some experience doing this for hobbyist purpose?
    I am planning to use Altera 7000s chips, and the free software they are offering. I selected Altera simply because my component vendor have them in hobbyist friendly 44 pin PLCC package 5 volt and 64 macro cells EPM7064SLC44-10 http://www.altera.com/literature/ds/m7000.pdf
    .I have done some testing and I am impressed. About how much logic functions I can squeeze in in one chip. And if something need to changed I can just change some code. Say you need a counter that counts up to 12 instead of 16. No problem, and no rewiring needed. And the programmer is just a LPT port and some 74HC244 chips. The programmer is supported by vendor, so it works. Not like some home brew PIC programmers.
     
    Last edited: Mar 26, 2011
  2. THE_RB

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    You have a wet dynamic RAM? :eek:

    More seriously, how much are the chips? Programmer?

    Some of the commercial apps I use a small PIC for could probably done with CPLD if the price is right. I'm keen to read about your experiences.
     
  3. t06afre

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    Eh...wet dram...huh how did that happened? But anyway good to see not all in this forum are conservative doodles:p
    Well my project. Which I hope you do not steal (joke). Is only on on the drawing board so far. Se the attached pdf. I plan to mount the CPLD on a vero board. And then piggyback this on a breadboard using wire wrap dil-headers with long pins. This is shown in page 1 and 2
    I have made a test project sim only. I have used free software from Altera. Quartus® II v10.1 Web Edition and ModelSim-Altera Starter Edition. You can find both Linux and Windows variants.
    https://www.altera.com/download/dnl-index.jsp
    The software will not expire.
    Designing is easy since you can use many 74xxx type circuits from a library. See page 3. You can draw a schematic or code in VHDL if you want. See page 4 and 5. This design use about 23% of the macrocells. The programmer cable easy to make. http://www.altera.com/literature/ug/ug_bbii.pdf
    It is a quite interesting hobbyist concept. Many functions like the decoder or the counter is scalable. Both in bits and modulus. No more "Darn I am out of 74xxx chips" It will not be able to replace all TTL like open collector variants. But still quite cool and useful. The cost for one chip is no more than a few TTLs purchased in small numbers. The example design is a light chaser. If this should be built with 74xxx variants. These ICs would be needed 74160, 74145, and two 7486. But for comercial projects. Well if speed is not needed. I think a PIC still would be cheaper in most cases
     
    Last edited: Mar 25, 2011
  4. mjhilger

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    Feb 28, 2011
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    Having used PLD's and FPGA's for a few years; I love them. As you note you can squeeze many things into one. I have loved the 22v10 for years. It was a GREAT day when Lattice introduced the EE programmable version (all previous were real fuses and one time program only - lots of wasted $$$). You are able to add/change functionality or fix certain problems easily.

    One drawback, and this depends on several factors, these can be more suspectable to glitches and/or power glitches causing internal changes. The older 74LS stuff ignored a lot of things. HC parts have their problems as well, but since they are single function, they were isolated and delt with eaisly. Make sure your power lines have caps appropriately and the clock and input sigs are fairly clean and you should really enjoy the advantages.
     
  5. THE_RB

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    Darn my Adobe is too old to open that PDF. Do you have a .GIF?

    I did notice their software says it's a 30 day trial, and does not have the full price shown?

    Yeouch!! Found it;
    Quartus® II software fixed-node subscription supporting all devices on Windows platforms. Includes subscription software updates for one year (1) $2,995

    (and every year after)Quartus II software per-seat renewal for a fixed-subscription license (3). $2,495
    USD

    :(
     
  6. t06afre

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    I have updated the pdf to adobe 5.0 Use the link in post 1. And this is from the download page
    I do not know why they call it web edition. Because it is installed 100% on you local hard-disk.
    Here is the Altera ftp download site ftp://ftp.altera.com/outgoing/release/
    It is public
     
    Last edited: Mar 26, 2011
  7. THE_RB

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    Sorry I was late getting back to the thread!

    Thanks for the info. :)

    I'm still a little wary, and pretty busy with commercial stuff for now. I'll take the easy option and let someone else get started with it, and see how they do. ;)
     
  8. t06afre

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    I am on it. I will order some parts and build the prototype much like the one I have suggested. Perhaps a digital clock If I can fit it in one chip. Will take a look in the weekend
     
  9. Wendy

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    Mar 24, 2008
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    Don't forget to show the schematics! :p

    An in joke, to a post in the Feedback forum.
     
  10. t06afre

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    Both schematics and code of course
     
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