fpga4fun.com

hi Rafael,

Rafael wrote:Do you know of any resources that can get me to the "hello world" stage?

I have no good hint here, but googling i found http://userweb.elec.gla.ac.uk/s/sroy2/DCD3/sources.pdf. I hope this helps.

Rafael wrote:What do I need to get started as inexpensively as possible?

If a simulation satifies you, you only need a freeware IDE from one of the FPGA manufacturers. If you want to see something in hardware, you need a development board and a programing cable.

Rafael wrote:Can I simply buy a USB cable that connects my PC directly to an FPGA to program it?

No, you need some programing hardware as no FPGA has a direct usb interface (at least not for programing the FPGA). There are cables which include this programing hardware, and there are development boards which include it.

Rafael wrote:Where can I buy a simple FPGA?

The FPGA alone can be bought from distributors (p.e. digikey). Development boards are available at the FPGA manufacturers, some distributors and some independant board development companies.

Rafael wrote:Buy the necessary equipment/interface to upload programming?

Cables which include the programing hardware are available at the manufacturers. If you buy a board which includes the programing hardware, you only need a plain usb cable which is included in the board accessoirs.

Rafael wrote:How much do the least expensive FPGAs cost?

Very small FPGAs can be bought for 5 EUROs (one piece, FPGA alone)
Cheap boards cost about 100 EUROs.
Cheapest i know:
http://www.altera.com/b/nios-bemicro-evaluation-kit.html
Some nice boards for first steps:
http://digilentinc.com/Products/Catalog.cfm?NavPath=2,400&Cat=10
The FPGA4FUN boards
http://www.knjn.com/
If you don't know which to buy, i recommend the Nexys2 FPGA Board.

Rafael wrote:Are there any simple beginner projects whereby the input and output both go through the PC interface?

Input and output going through the PC interface is simple if you use an SOPC builder, but i guess that is not what you want to do. Use buttons as input and LEDs as output for your first designs.

EDIT: changed recommendation from Spartan 3 Starter board to Nexsys2, because Nexsys2 includes programming hardware.

What do I need to get started as inexpensively as possible?

I started on a Digilent Nexys2, but a Basys2 is cheaper. Nothing else is needed - other than a fat pipe to the internet to down load software.

Using the Nexys2's onboard RAM and Flash is a bit complex (as they are 75ns devices and the boards run on a 20ns clock) but not too hard. The Basys2-100 has about 8kB of easy to use block RAM in the FPGA, and the Nexys2-1200 has about 56kB of block RAM, which may be deciding factor.

Can I simply buy a USB cable that connects my PC directly to an FPGA to program it?

Yes. The Nexys2 & Basys2 have "USB to JTAG" built in to them. They can also be powered down the USB - so only one cable is needed.

Where can I buy a simple FPGA?

http://www.digilentinc.com/

Buy the necessary equipment/interface to upload programming?

Not needed

How much do the least expensive FPGAs cost?

US$79 unless you are training in a University.

Are there any simple beginner projects whereby the input and output both go through the PC interface?

Yes. The Digilent resources includes a PC controlled virtual interface - look at "Adept IOExpansion.zip". You download the design and it gives you virtual buttons and data transfer down the USB interface. To the FPGA it looks like an 8bit bidirectional data bus with 3 control signals.

Developing custom code to talk to the FPGA isn't that hard. The API is fully documented. I get about 11MB/s to my Nexys2. Look for "DPCUTIL Programmer's Reference Manual" under the "Software/Adept 2" category.

Any answers you can provide will be greatly appreciated.

You are welcome!