Extracting timing from a demo board (V2MB1000)

Hello all, I'm trying to get a DDR SDRAM controller working reliably on Insight/Memec's V2MB1000 development board, but I'm having some timing issues. I'm trying to correctly constrain my timing, and verify using timing simulations, but I'm running into problems because I have no information about the board delays between the memory and the FPGA. I especially need the clock feedback path delay (to set the DCM FEEDBACK constraint), and the skew between the dqs lines and data (to know if I can use dqs to latch data)

I don't have board layout information, and Insight/Memec hasn't yet answered my requests (although, in their defence, it _has_ been less than a week...), and I haven't found the info anywhere on their site or in the provided documentation. As far as probing is concerned, I only have access to the memory's pins, so I'm not sure how I can determine the delays from this.

So, what I was hoping to get is either suggestions about how I might measure these delays, or, if someone has already measured/received this information, the actual min:typ:max board delays between memory and FPGA.

Thanks a lot in advance!

Board delays are normally 1-2 nS which should be much less than a clock period which is the minimum wait for a synchronous controller.

With a handshaking interface, you don't need to measure the delays, you just drive a READY wait for an ACK.

-- Mike Treseler

Hi Pierre,

I can't answer your question directly, but can offer a set of numbers (parameters and constraints etc) for the EDK-provided DDR controller that work on the v2mb1000 board... perhaps you can extract what you need from these?

Regards,

John

(sound of hand slapping forehead) Thanks for the idea, I should have thought of that myself... I already have the EDK and all associated pcores, so I'll see what I can get from that (unless you have stuff that isn't in the vhdl files?). Of course, I always prefer to know as much as I can about the tools I use, so if anyone has the information, I'd still be interested in getting it. Thanks again,