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Cool little FPGA — Parallax Forums

Cool little FPGA

Jay KickliterJay Kickliter Posts: 446
edited 2012-01-12 01:19 in General Discussion
Has anyone tried these GreenPak FPGA's? I heard about them on The Amp Hour, and Nice Chips. Dave L. Jones kept going on about the limitations, but he seemed to think they were cool.

I wonder what these things are actually being used for.

Comments

  • Jay KickliterJay Kickliter Posts: 446
    edited 2011-10-31 07:40
    I originally added a line saying I didn't think it was actually an FPGA, but deleted it cause I don't actually know what I'm talking about and didnt want to be that guy. thanks for confirming my suspicion. they still seem cool. I like the development software and the fact they have an OS X version. I think I'll order one of the kits.
  • GadgetmanGadgetman Posts: 2,436
    edited 2011-10-31 09:17
    I haven't studied it that much, but at the price they list, I'm sorely tempted to get the kit, just for the geek-factor.
    Of course, the video with the synthetic voice on the webpage the link pointed to, was almost enough to make me flee in terror.
  • Jay KickliterJay Kickliter Posts: 446
    edited 2011-10-31 09:49
    Here's an article on EETimes.
  • Bob Lawrence (VE1RLL)Bob Lawrence (VE1RLL) Posts: 1,720
    edited 2011-10-31 17:31
    re:I originally added a line saying I didn't think it was actually an FPGA, but deleted it cause I don't actually know what I'm talking about

    From the Wiki: http://en.wikipedia.org/wiki/Configurable_Mixed-signal_IC

    "The GreenPAK2 SLG46400 is Silego's second generation GreenPAK product and is a one-time programmable micro-FPGA with programmable analog components and comes in a small 2.5mm x 2.5mm TDFN-12 package"
    It certainly is a interesting product and priced just right for experimenters.
  • AleAle Posts: 2,363
    edited 2011-11-01 11:53
    There was here a thread about them some time ago. I looked into it, the one time programmability was what made me not consider them for my projects, thiugh I can see them being quite useful as supervisory circuits and such. The wide supply range is something other FPGA do not have, nor the analog parts.
  • rod1963rod1963 Posts: 752
    edited 2011-11-01 12:18
    Lattice has their MachX02 line, it has a hardwired SPI, I2C and a 16 bit counter timer. I'm just waiting until their 32QFN package version to be released.

    http://www.latticesemi.com/products/cpld/machxo2/index.cfm
  • Jay KickliterJay Kickliter Posts: 446
    edited 2012-01-08 06:29
    I just got the GreenPAK2 and it is a cool little device. I just wish it had a few more pins. Also, the software and documentation is incomplete. Silego claims it does slave SPI, but the graphic software (otherwise very nice) won't allow me to connect MOSI to an input pin. Also, I can't find any mention in the datasheet of a register that will allow me to set's MOSI's input pin, just MISO. Either it's an omission, or SPI just doesn't work on this chip. A bit disappointing, since this chip is so cheap and should have been able to do what I need.

    On that note, I looked at the MachX02. Looks nice, except that it costs at least 10X as much as the GreenPAK2. Does anyone have any suggestions for anything in between that is really cheap. What I need is a chip that can do PWM for motor control. My original idea was to use one GreenPAK per motor, since they are only $0.30, but Silego's not getting back to me on the aforementioned problem. We'd do everything on the Prop, but ran out of cogs and pins a while ago (doing lots of multiplexing already).
    rod1963 wrote: »
    Lattice has their MachX02 line, it has a hardwired SPI, I2C and a 16 bit counter timer. I'm just waiting until their 32QFN package version to be released.

    http://www.latticesemi.com/products/cpld/machxo2/index.cfm
  • LeonLeon Posts: 7,620
    edited 2012-01-08 07:01
    Some of the latest PICs, such as the 16F1503, have configurable logic functions, as well as the usual PWM and other peripherals:

    http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en553475
  • Cluso99Cluso99 Posts: 18,069
    edited 2012-01-08 15:33
    I had an interesting discussion by email with the GreenPak guys. Unfortunately, they are not interested in their devices being used as simple logic replacements and only interested in really high volume customers where they pre-program the chips. Its a shame, because I see there is a market for those chips elsewhere too. So I decided not to get the kit :(
  • jmgjmg Posts: 15,189
    edited 2012-01-09 22:13
    Jay Kickliter wrote: »
    On that note, I looked at the MachX02. Looks nice, except that it costs at least 10X as much as the GreenPAK2. Does anyone have any suggestions for anything in between that is really cheap. What I need is a chip that can do PWM for motor control.

    The MachXO2 are still not in stock in anything other than 1200 sizes, and the indicated prices for the smaller parts are VERY expensive.
    (just a few % down on the 1200 price ?! )

    For your PWM expansion, a tiny Microcontroller will always be cheaper than a CPLD, unless there is some complexity or speed dictate that means the uC just does not cut it.
    For CPLD look at also the Lattice Mach4000Z, the Altera MAX V (much more linear price curve than the MachXO2, but 0.4mm pins) and the CoolRunner parts from Xilinx, or Atmel ATF15xx family.



    For small uC (depends on how many PWMs you need) look at TI MSO430Gxx series, or MicroChip, 14 pin parts,
    and I did see NXP and Microchip having bragging contests about TSSOP20 package 32 bit cores... These do not seem to be real yet.

    Of course, if you already have packed out a Prop, then you know it well, and should consider a pair ?
    ( 2 or 3 Prop would also migrate to Prop II quite easily )...
  • Jay KickliterJay Kickliter Posts: 446
    edited 2012-01-10 04:44
    Cluso99 wrote: »
    I had an interesting discussion by email with the GreenPak guys. Unfortunately, they are not interested in their devices being used as simple logic replacements and only interested in really high volume customers where they pre-program the chips. Its a shame, because I see there is a market for those chips elsewhere too. So I decided not to get the kit :(

    Do you mean they want to do those design also? Is that why I don't see the chips sold by any of regular suppliers?
  • Jay KickliterJay Kickliter Posts: 446
    edited 2012-01-10 04:57
    I got an email back Silego right after I figured out that the SPI does work after all. It turns out you just have to trust the datasheet and ignore some of what the software says. They said they'll issue a software update this week. Now that I have this thing working I think I can recommend it to others. They have different programs for the GreeenPAK I and II. Since II is fairly new I guess they're still working on bugs. I do think they need to work on their documentation though. There's lots of inconstancies between what they call something on their web page, datasheet, and the software. Take S2P, or what they also call the SPI interface. On the datasheet they refer to the data lines as SDI and SDO, in the GUI software they're called MOSI and MISO. And in the datasheet they show them as a single bi directional line, but the GUI shows them as separate lines.

    All my complaining aside, they're really useful chips. I'd be interested to see what other people come up with using them.

    (Sent from my pocket computer)
  • LeonLeon Posts: 7,620
    edited 2012-01-10 04:59
    jmg wrote: »
    For small uC (depends on how many PWMs you need) look at TI MSO430Gxx series, or MicroChip, 14 pin parts,
    and I did see NXP and Microchip having bragging contests about TSSOP20 package 32 bit cores... These do not seem to be real yet.

    Microchip is shipping the PIC32 (MIPS core) in 28-pin DIP:

    http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en555993

    I've got one of the new MicroStick II boards, which came with one, and bought a few more.

    SSOP parts are available:

    http://www.microchipdirect.com/productdetails.aspx?mid=10&catalog=buymicrochip&category=PIC32MX120F032B

    Here is a useful document describing the new 8-bit PICs with configurable logic:

    http://ww1.microchip.com/downloads/en/DeviceDoc/41565c.pdf

    I've got some of them but have yet to try that feature.
  • Cluso99Cluso99 Posts: 18,069
    edited 2012-01-10 19:19
    Silego wants to supply programmed chips (to your specs) in large quantities. While you can get unprogrammed chips from them, because they are not interested in low volumes, I am not certain they will continue to supply unprogrammed chips in low volumes. Hence they are of no use to me because I cannot guarantee supply.
  • jmgjmg Posts: 15,189
    edited 2012-01-10 20:52
    Cluso99 wrote: »
    Silego wants to supply programmed chips (to your specs) in large quantities. While you can get unprogrammed chips from them, because they are not interested in low volumes, I am not certain they will continue to supply unprogrammed chips in low volumes. Hence they are of no use to me because I cannot guarantee supply.

    Depends what 'low volumes' and 'high volumes' really mean ?

    They have an on line store, and will sell in multiples of 100, and also have a ZIF socket and PGMR/Tools at good prices.

    Their devices are OTP, and MLF, so that in itself pretty much excludes one-off experimenter usage.

    If you are going to tool for production and SMD assembly, their web store should provide any volumes you need (over 100)
  • Cluso99Cluso99 Posts: 18,069
    edited 2012-01-12 01:19
    My concern is that they could remove the qty 100 at any time! They just are not interested in anyone using those volumes. Or the price could rise dramatically. Just cannot afford to use them with their current stance.
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