[SI-LIST] Re: DRAM Address lines : Daisy Chain or "T"?

Erwin, if you make a T with significant stubs then you will need a driver 
capable of driving one half the line impedance and separate damping 
resistors for each of the two segments.    If the segments are unequal 
length, then you will also get some additional ringback.

If you drive a daisy chain, then if the nearest load will not settle until 
2*Tflight_far - Tflight_near

Steve.
At 02:13 PM 7/27/2004 +0800, SEOW, ERWIN wrote:
>Hi SI gurus,
>
>I am presently routing a board using 2 DDR RAMS. I would like to know
>how do we route the common lines (Eg Address lines) ?
>
>Do we use Daisy Chain?
>
>Or a "T" where the driver is at the bottom and splits to each ot the
>DRAMS?
>
>Of the 2 methods, what are the pros and cons?
>
>Thanks in advance!
>
>Best regards
>
>Erwin Seow
>
>
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