Re: gEDA-user: terminators

[gene glick <carzrgr8@xxxxxxxxxxxxx>]

Tim Hanson wrote:

> I've laid out an interface to a 133Mhz SDRAM, and the path lengths
> were similar to yours.  Works great.  No LA connector, though.
> Tim
> 

I just looked at the reference design for atmel AT91SAM9260 and it uses 
similar if not the same memory.  Guess what, no clock termination.  I 
can't find any gerbers though, and the pcb file is for snOrcad.  If we 
could get a peek at the layout maybe some insight into a working layout.

The only picture I've found is a top view of the board but it doesn't 
show the traces.  The sdram appears not too close to the micro.  Wish I 
could see those traces.

Maybe Tim is is right.  Still, I'd watch your timing budget closely and 
probably terminate the clock line.

DJ, you could consider the XC3S200-4PQG208C for additional IO.  $20 from 
digikey.


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