[LinuxBIOS] SPD Logical and Physical Banks

[Uwe Hermann]

On Tue, May 15, 2007 at 04:45:53AM -0400, Corey Osgood wrote:
> joe at smittys.pointclark.net wrote:
> > Hello,
> > Can someone please explain to me the difference between Logical and  
> > Physical Banks on SDRAM? I am looking for a quick and dirty way to  
> > determine if the SDRAM module is single sided or double sided through  
> > SPD. Would I use the Logical (SPD Byte 17) or Physical (SPD Byte 5)  
> > Bank for that?
> > 
> > Thanks - Joe
> > 
> 
> Well, in the best case, neither. Read the Intel SPD standard
> (http://www.intel.com/design/chipsets/memory/spdsd12a.pdf), I've checked
> several PC66, 100, and 133 dimms, and all of them so far support it.
> Check out bytes 126 and 127. If that doesn't work out though, you're
> looking for byte 5.

Just to prevent unnecessary duplicated work: please don't write
SPD-related functions for 440BX. I'm about to finish a patch which moves
all generic SPD-related functions into src/sdram/spd.c where all
chipsets can use them.

The SPD-only stuff should be chipset-independent, only the
chipset-specific stuff should be handled in the respective raminit.c.


Uwe.
-- 
http://www.hermann-uwe.de  | http://www.holsham-traders.de
http://www.crazy-hacks.org | http://www.unmaintained-free-software.org
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