mpc5200 and ddr

[Ho Jeffrey-r26191]

Have you check AN2582 which is DDR design for MPC85xx. Even thought the part used is different, most of the general DDR design rules can be find  in this docu.

Regards,
Jeffrey Ho

-----Original Message-----
From: owner-linuxppc-embedded at lists.linuxppc.org [mailto:owner-linuxppc-embedded at lists.linuxppc.org] On Behalf Of Andrew Dennison
Sent: Thursday, August 26, 2004 8:56 AM
To: 'Andrey Volkov'; 'Sylvain Munaut'
Cc: linuxppc-embedded at lists.linuxppc.org
Subject: RE: Re[2]: mpc5200 and ddr



> 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


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