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  • Author Author: mraureliusr
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My First FPGA!

mraureliusr

So today I picked up my first FPGA! It was a sample that I got from Atmel, the AT40K40AL. I had no idea that the part was selling for about $85 on some electronic parts suppliers websites!!!

 

The problem is, I can't seem to find any tools to write Verilog for it. I've already spun a PCB to break out all the pins to headers, but I'm debating whether to even get it made as I can't get any leads on what software to use. The only page on the entire Atmel site that seems to have any info on their FPGA ISE is here: http://www.atmel.com/tools/FPGAINTEGRATEDDEVELOPMENTSYSTEMS_IDS_.aspx

 

That gives you a program, id76install.exe, which I ran, and it seemed to be the correct installer. It installed a program called Atmel IDS 7.6. However, it won't launch! Even on my (pretty damn good) computer, it crashes every time I try to open it. I would really love to get some feedback from the community here! I might post something in some forums and try to dig deeper. I've already been on AVRFreaks to see if anyone has experience with the IDS, but there wasn't a lot of info. I know their FPGAs aren't their flagship products, but you think that there'd be a little more support than there is. Xilinx, for example, has a completely free version of their tools -- Vivado WebPack. You're obviously restricted for a lot of things, but hey, at least it's usable. And I'm only trying to learn the basic here. I just want to start learning Verilog. Not off to a great start.

 

I might just pick up a Xilinx Spartan-3E or similar. Decently priced, I already have the software installed. I'd just have to pick up a programmer. I may as well pick up one of those dev boards off eBay. I think they've implemented JTAG over USB so it makes it really easy to program. They have on-board EEPROMs to store the FPGA config data, as well, plus a whole bunch of peripherals (7-segment displays, buttons, LEDs, and they usually have LCD screens that you can plug in to some of the headers to display data). I think they cost around $70-100 but it might be the best way to go.

 

I'd really appreciate any advice from anyone who has experience dipping their toes into the FPGA world. Ideally, I'd like to get started with the Atmel FPGA (as it's already in my hands) but if that's out of the picture then I guess I'll just make a necklace out of it or something.

  • in reply to michaelkellett

    Michael Kellett wrote:

     

    Xilinx only seem to be interested in huge mega performance parts for the future and have done little in the low cost small device area for some time.

    This is true, but their low-cost smallish device offerings are quite good.  I really like the Spartan 3A, and the smallest "50K gate" part can do a great deal for a few dollars.  I haven't tried the Spartan 6 yet, but it looks very powerful indeed.  And for CPLDs, the long-in-the-tooth XC9500XL series is still a great 3.3V part with 5V tolerance and modest power consumption.  And it's practically the only CPLD you can still get in socketable PLCC image

     

    Xilinx Spartan comes in waves.  Basically, you wait for Xilinx to squeeze all the easy profits out of a new technology and then get a mature process for cheap.  It took many years before Spartan 3 became more attractive than Spartan IIE.  I do hope they'll provide a cheap Spartan 6 with PCI express some day.  Right now their cheapest chip with PCIe is still awfully expensive.

  • You may have a collector's item.  Atmel at one time had (or still has) an FPGA with an open architecture so you can program it at the bit level instead of having to use the vendor's tools.  I don't know if the AT40K is the one that has that honor.

     

    In any case, Michael is right in that Atmel isn't much in the FPGA game these days.  I do most of my FPGA work with Xilinx Spartan 3A, which is a very nice architecture.  You can get a Papilio One with a 250K gate Spartan 3E for US$38, which is probably your best Xilinx development board value these days.  I like Lattice's new iCE40 series, though I haven't done any actual designs with it, nor have I tried the tools.  You can get an iCEstick evaluation board for US$25, which is pretty attractive.  I've also used Actel Pro ASIC 3 and Igloo.  They're pretty nice parts, but I like the Spartan 3 and iCE40 architectures better, and IMO the tools are a pain compared to Xilinx.

     

    In terms of learning Verilog, you can download Xilinx and/or Lattice software for free and try simulating some designs.  There are also open-source Verilog simulators such as Icarus.  I don't have any recent experience with Verilog simulators.  I far prefer to download a design to a development board or prototype and use a sillyscope.  In my own work, this is a lot quicker and easier than preparing the test bench needed to talk to my design.

     

    The most recent software I've used is Xilinx ISE WebPACK 12.4.  I haven't tried Vivado.  My experience with Xilinx is that they have problems with tool regression so you're best off using a version that was current when your chip came out.  So I like 12.2 or 12.4 for Spartan 3A and 5.2 for Spartan IIE and XC9572XL CPLDs.  Xilinx lets you download old versions of the tools back to WebPACK 3.3: see Xilinx Classics.  I've also found that the tools get larger, more complex, and slower with each generation.

  • I wouldn't use an Atmel FPGA for a new design or to start working with FPGAs. It's a very old design and Atmel are no longer any sort of a contender in the FPGA market. There are 4 players you might consider for starting out:

    Altera

    Lattice

    MicroSemi

    Xilinx

     

    I would recomend Lattice, followed by MicroSemi, then Altera then Xilinx - this is based on the focus on small low cost parts from the 4 of them. Xilinx only seem to be interested in huge mega performance parts for the future and have done little in the low cost small device area for some time. Altera are much the same but perhaps a little broader. Lattice are interested in cheap simple parts and are very active in this area. MicroSemi are more at the low end (than A or X) but I have very little experience of their stuff.

    Take a look at the Lattice ICE40HX1k, machX02 and the XP2 range of parts.

     

    MK