From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Andrew Dennison" To: "'Andrey Volkov'" , "'Sylvain Munaut'" Cc: Subject: RE: Re[2]: mpc5200 and ddr Date: Thu, 26 Aug 2004 10:55:41 +1000 Message-ID: <001e01c48b07$68c32d30$ee00a8c0@CAT> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" In-reply-to: <1134038006.20040825205207@varma-el.com> Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: > Andrey Volkov wrote: > > Hello Sylvain, > > Wednesday, August 25, 2004, 8:35:25 PM, you wrote: > > > Hi, > > > Sorry I don't have informations, but I'm interested too ;) > > > I guess you just "connect" them, but I wonder about > terminations ? ( or > > maybe keeping short trace is ok ? ). > > > Certainly - termination, time diagrams, restrictions (especially > capacitors length and likewise) etc. As I wrote before > datasheet very foggy and miserly, but may be David or > somebody from freescale > enlighten me, if so, then I send info to ml. > Hello Andrey, Sylvain, Micron have a tech note (TN4606) on DDR termination for point-to-point systems. Have a look at this if you are working on a design with DDR chips on the PCB. It appears that series termination is sufficient with short (<50mm) track lengths. However DDR timing requires some careful attention to layout (impedence control and track length matching) so all the information I have found on DDR is always qualified by "simulate your design". My local Freescale FAE was able to supply some additional information so maybe you can ask yours? Andrew ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/