04-11-2010 08:31 PM - edited 04-21-2010 10:29 AM
I'm not new to electronics or programmiing, just to PLDs.
I'm thinking of using a FPGA in a project but am not sure where to start. I'm trying to keep the costs as low as possible at the moment so I was looking at an Amontec USB JTAGKey. I make my own prototype boards so I don't want to buy any devleopment boards, just be able to program the chips in circuit. My questions are:
1. Will this program most Xlinix FPGAs okay?
2. Is it compatible with the Xlinix logic development platform software? If not what do I write the code with?
3. If the above answers are no, what is a decent cheap way of programming these chips?
I realise these might be stupid questions, but I'm completely new to this field, any help would be much appreciated.
04-22-2010 08:38 PM
04-22-2010 08:38 PM
04-23-2010 05:22 AM
Thanks for the reply, just the kind of info I was looking for.
I think I'll skip the Amontec JTAG Key, if only for the reason I sent them 4 e-mails asking them about the device, and have still received no reply - pity, as it looks like a good product.
Looks like I'll go the ebay route, I found one for £57 ($89) which looks pretty good, and comes with various connection options.
04-23-2010 11:30 AM
While I was on ebay I noticed that there is a Spartan Starter Kit for $67, current bid. Something like that would help you get up to speed and you would not need the JTAG dongle ... altho you would still need it when you do your own board.
The particlar one one ebay is the older and fairly small FPGA, but maybe a Spartan 3E or 3A Starter Kit will come along in the future. It looks like it uses the old parallel port programming cable. The programming cable itself might be worth checking out if you are looking to save money, altho I'm not sure it works with the newer FPGAs.
Actually the starter kits are not all that expensive new. I checked, and the price for a new 3A starter kit on Avnet is $189. It has the 3A-700 FPGA on it which is large enough if you want to experiment with putting a CPU like MicroBlaze on it.
Go to http://avnetexpress.avnet.com and enter " Xilinx starter kit " in search box.
I mention it because having a starter kit helped me greatly when I was learning FPGAs, VHDL and Verilog.
04-23-2010 01:48 PM
The starter kit sounds like a good idea, I'll have a look for a cheap one, be good just to get going with stuff. I am part of a small business and etch my own prototype boards to save money, I have managed to deal with the fine pitch SMD stuff okay, and it works well for rough ideas.
The main reason for wanting to get into the FPGAs and CPLDs (apart from the fact that they will become increasingly popular) is that I have a prototype USB Oscilloscope based on a PIC32, and would like to speed up the sample rate without resorting to standard logic.
Also I would like not to have to use an external EEPROM to load the FPGA with - I know the proAsic from Actel have flash memory, are there any similar FPGAs from Xilinx? I'll have a look anyway but if you have any recommendations that would be great.
Thanks for the help.
04-23-2010 04:36 PM
I just finished a project using the Xilinx XC3S50AN FPGA, and it worked really well. Cost is about $9 in single quantity. It has on-chip flash, so you don't need an external flash. 50K gates in a QFP 144 flat pack. If you want more logic, you have to move to a BGA package.