Inexpensive Xilinx PLD/FPGA Configuration

[jobattle]

I am looking for a way for students to be able to inexpensively program a CPLD or FPGA. Ideally this would be a device that could be assembled by the student/reader for a small amount of money and would be capable or operating under Windows/Mac/Linux Operating Systems. It would also be best if the programmer could function with Impact in as simple a manner as possible.

I intend to design an inexpensive development board tto use as a teaching aide and I need a way for the student and/or reader to configure it after developing applicatins under WebPack ISE.

Anyone have any syuggestions?

 

[mrflibble]

Digilent has pretty cheap programmers:

**broken link removed**

If you make sure the dev board you design can be programmed with that jtag connection you're all set.

The digilent programmers I know work from impact. You have to select digilent_plugin in impact.

Or you can have them solder their own cables and have it not work for various intriguing reasons. Not sure if that is part of the didactic component you're aiming for. If it is, by all means let them have them do their own cables and prepare for some troubleshooting.

I've made my own programmers in the past. Don't do that anymore because nowadays the programmers are affordable.

 

[jobattle]

I'd be interested in how you did your own programmers. It would be nice to incorporate a programmer into the board and just have a USB connector to make things simple, but it would have to be pretty cheap.

 

[mrflibble]

That's a few years ago now. It was parallel port only, and it didn't work from impact. I programmed it with urjtag

You can google "xilinx dlc5" for links of parallel download cable III designs.

Parallel Cable III (DLC 5) Schematic


If I had to do it now, and it had to be USB, and was for xilinx I think I'd look into using the CY7C68013A.

It's about $6 - $10 in singles at futureelectronics / digikey / mouser

Incidentally, this is the same ucontroller as used on some of the fpga dev. boards out there. If you are putting together the dev board then you can connect the ez-usb such that you have both a programming interface and also an usb fifo. Obviously work required... But hey, it's either buy something that is known to work, or spend time doing it yourself.

For this approach, also check out: **broken link removed**

Oh, and cheap, easy, DIY, usb and fool proof are somewhat mutually exclusive in several permutations of those words.

 

[guitarguy12387]

If you're using a digilent dev board for lower end devices (i.e. spartan), which i assume that's all you will need for teaching, you can program via jtag right over usb. No need for another programmer for config.

 

[mrflibble]

Indeed. But if I understood the OP correctly he intends to make his own dev board to be used in this class.

I intend to design an inexpensive development board tto use as a teaching aide and I need a way for the student and/or reader to configure it after developing applicatins under WebPack ISE.

I noticed the basys2 is $49 student pricing. Suppose it's only 10 boards or so it might make sense to just buy it. If it's say 100 it might be different. And as you pointed out, that board can be programmed over usb without needing any extra's.

See .

Too bad really that the avnet spartan-3a board was discontinued. That was also a very good value for money board.

 

[guitarguy12387]

Ohhh touche. I missed that. My apologies, carry on.

 

[bigdogguru]

Another option if you decide to go with a separate JTAG programmer, rather than incorporate it into your design would be run a search for "Xilinx JTAG" on ebay. I recently had to purchase two units, Xilinx Platform Cable USB compatible, while in a pinch, $35 each shipping included.

They performed as expected and used the Xilinx drivers provided by Impact. If you were purchasing quantity, I'm sure they would be will to deal.

BigDog