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Mohammed,
I use two
B5-Spartan2+ boards from Tony Burch in Australia. They have worked flawlessly so
far.
You have to work
out a few things before you pick a board.
1. Speed of
device required if you wish to run it fast say 100+ mhz, some boards use -5
devices which are
slower than -6 so
be careful on this one. I think there are -7 devices and maybe -8 out but I've
not really
bothered with
them as my -5 device boards run sweet at full 100mhz so I'm happy (for
now).
2. The number of
I/O pins you require to be able to connect to. Some boards bring all the pins
from the FPGA
out to headers,
some do just the I/O and Power pins whilst some just give you a token few to
play with.
3. The amount of
gates in the device. Most boards feature a 200K gate FPGA now so this should do
any new
designs unless
you are planning a huge complex HDL design?
4. Also be
careful about how the boards need to be programmed, some of them require you to
buy a special
cable which can
cost $100+ just for the cable!
I would recommend
looking at the following for good quality 'learner boards'
(http://www.xess.com)
There are boards
available for the faster, more I/O pins or more gate count FPGAs but the price
increases
when your
requirements do.
Paul
PS Does anybody
know offhand just what max speed a -5 is supposed to be able to do. I don't
imagine putting the
100mhz clock into
a x2 DLL and then running off this will be too likely to succeed! But I would
like to know for
future reference,
I'm too busy to sit and download all the Spartan2 manuals off the Xilinx
site. ;-)
I have seen the
DDR SDRAM controller is recommended to use a -6 spec FPGA but it didn't give
anymore details.
Can a -5 do a
133mhz SDRAM interface or would I be limited to 100mhz
version?
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