Spartan-3E or Generic FPGA -> PC133 interface details??

Do you have a question? Post it now! No Registration Necessary

Translate This Thread From English to

Threaded View
Hi, recently I've started using FPGAs for all sorts of things, and
currently I'm working on a couple designs that would benefit from a
PC133 interface. I'll be putting it all on a rather tiny PCB with a
Spartan-3E and a laptop-form-factor RAM socket, so the traces will be
short. However, I am completely self-taught and after some
newsgroup/google surfing, it seems I may need series resistors or some
such things?? (I don't quite understand all this business about trace
impedance, I started learning on 8-bit 20MHz MCUs and before that I was
a software-only person :| )

Could anyone explain these things to me or point me to some good online

Thanks in advance!
-Eric Agan

Re: Spartan-3E or Generic FPGA -> PC133 interface details??
Because you worked at such slow speeds before you probably have never had to
care about trace impedance or termination.  As you use higher speed
communication standards (ones with fast edge rates), you will need to master
signal integrity.  It might not be a huge problem with your current needs as
PC133 SDR shouldn't be that bad.  But, I would suggest you read some of the
signal integrity articles on the Xilinx site and get a few of  Howard
Johnson's books on signal integrity.  I would also recommend a good PCB
design suite that includes a simulation program.  I use Hyperlynx from
Mentor Graphics.

---Matthew Hicks

Quoted text here. Click to load it

Re: Spartan-3E or Generic FPGA -> PC133 interface details??
Quoted text here. Click to load it

I strongly suggest you try and master some transmission line theory (in
which signal integrity is based).

There are some excellent resources available on the web, but you might
need some guidance. For that reason, I have x-posted this to s.e.d.



Site Timeline