how to make an FPGA kit from scratch

[jigjack]

i want to create a kit of my own for FPGA programming.

i m familiar with xilinx project manager, model sim, leonardo spectrum...

now, i plan for SPARTAN II fpga, A flash PROM, Alevel shifter to interface with TTL logic, and some voltage regulator ic to supply 3.3, 2.5 and 5 V for my board.

my questions r ....
have anyone made such a board earlier?
what will be the cost ? ( i m from PUNE, INDIA)
how do i connect the board to PC?
if anyone could help me figurre out the price list of XILINx FPGA that will ba gr8 help.

please help.
thankx in advance
-jigar

 

[SphinX]

Salam,

Here is a cheap Spartan-3 Developement Kit, I will order my board soon

https://www.xilinx.com/products/spartan3/s3boards.htm

SphinX

 

[Big Boy]

You can get good eval boards at 99$ (don't buy anything lower that this, though...).

Designing your own board will cost you the FPGA, the flash PROM (which are not soo cheap also), the PCB and the other components. Plus having to design it, and wandering if it will work the first time...

Though, there are times when designing custom board can be handy. For example, once you tested a design on an eval board, you probably have added some component to the board, and some components of the board you don't use. If you wish to make a custom design for that specific project, then, making your own board can be good. Remember that you'll need some experience with soldering surface mount chips.

For a start though, it's easier to get a pre-made board.

 

[hunter694]

Hi,

I have created such a board.

Here are some tips:

1/ make the board 4-layer. since the FPGA is sensitive to noise. (top and bottom layers for signals, 1 GND, 1 Vcc)

2/ Fabrication of such a board should not cost you more than Rs. 3,000 - 4,000 (I am from Islamabad, Pakistan) please let me know how much it costs you over there

3/ You can put a simple RS-232 transceiver and interface it with FPGA on your board. I like MAX3243 for UART mode and MAX3221 for SIO mode.

4/ Spartan FPGA are cheap, you can actually get a pretty good one (50,000 gates or so) in less than $75.


Regards,
Hunter

 

[Big Boy]

I know of Olimex who provide single and two layers on their site. Though, options can be added if you ask the person in charge. They probably can do 4-layers, for some extra bucks.

Anyway, when I do PCB stuff, I get the bords from them. You just give gerber files...

They have a lot of standard feature, and is very cheap (compared to Americas prices).

Standard features include

- Sinkscreen on one side (for 1 and 2-sided)
- Soldermask (the green coating) on each sides (1 for 1-sided, 2 for 2-sided)
- Plated holes for 2-sided
- Panelizing and multi-design allowed (you have a custom board size that is fixed at X per Y, if you have a desing that use only 1 third, you can copy it 3 times, or use 2, 3, ..., different desings to fill that board area)
- Each desings or panels are cut. The wasted areas (the distence from the cut to where your traces shall end) is very thin, in the order of a few millimiters.
- No setup cost, additional request for the same design in the future you save something like 20%.
- Last time I checked, 21$ for 1-sided, 26 for 2-sided, including all what's mentionned above.

Now, try to find this in USA/Canada!

They easily ship anywhere in the world, and the s&h cost is descent too. Boards made fast too (3~5 work day if traces/spaces larger or equal to 10 mils, 0.254 mm). Note that some of the finest TSSOP are 0.250mm, but I asked the question, and the person there told me that using 0.250mm could be passed using their regular process.

What's nice too is that if you exceed in something, like the max number of holes per board, non-standard drill size, ..., they just charge you minimal extras.

If you design for them to process your board, I suggest you read their site PCB rules page. In most PCB programs, it's just a matter of defining board rules. About the only thing to really watch is the silkscreen (the text and drawing) traces width, which need to be > or = to 10 mils. Many PCB programs have libraries that use 8 mils silkscreen traces. Though, for example, in ProtelDXP, you have a post-process that can work with gerber files, and you can re-define silkscreen traces width. Probably the other tools or gerber editors have this.

Big Boy

 

[Ace-X]

Check this:

**broken link removed**

Good description with full schematic.

Ace-X.

 

[djolestojic]

In order to debbug the FPGA, it is better to use the parallel cable III to directly program FPGA, to avoid the use of serial eeprom during the develpment phase.

The parallel cable schematics can be found on the Xilinx website.

 

[Mazi3]

i've designed spartan 2 board on double layer board.
at bottom was power supply network under IC,
feeding lines for this were connected from diagonal,
and there was whole gnd plane to connectors.

signals were routet on top layer.

flow was: power => signals => programming signals

all routing was manual

 

[raju_tawade]

Hi !!
if you r from pune then you may get the idea of FPGA cost from Rajeev Electronics,pune

 

[pankaj]

Hi jigjack,

I ma also from Pune. Once upon a time I also wanted to make my own kit but the costs have always been prohibitive. Making your own kit will make you rpoorer by atleast 60000 - 70000. Buying one will cheaper.

Pankaj

 

[abhijitk85]

An open source and low cost board design can be found at opencores:
**broken link removed**