RE: My First FPGA!

johnbeetem — Wed, 27 Nov 2013 18:43:03 GMT

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.

RE: My First FPGA!

michaelkellett — Wed, 27 Nov 2013 08:48:07 GMT

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.