[SunHELP] Re: Another possibly unanswerable question about AXI memory (fwd)

[Michael Horton]

Call Hitachi or, at least, check their website.  My
experience is that larger companies have more
information than you would ever need.  (I once called
NEC about a 6-8 year old SCSI hard drive.  They routed
me to the engineer that "owned" the information.  He
faxed me 8-10 pages of technical information.)

The Sun labeled Ultra, according to the FE handbook,
"The 50ns DIMMs are sold in the Ultra 5/10 [greater
than or equal to] 360MHz 24-Bit PGX." (Volume 1,
Memory-4).

Also, "The minimum memory requirement is two DIMMs in
any bank."; "The 32, 64, 128, and 256MB DIMMs use
11-bit column addressing."; "If 10-bit and 11-bit
DIMMs are mixed, either pair will be ignored.";
"Memory speed is 60nx if 50ns and 60ns DIMMs are
mixed."; "System Boards 375-0066 and 375-0079 support
50nx memory speed." (Volume 1, Memory-16).


Hope this helps,

MH


--- Robert Novak <rnovak at indyramp.com> wrote:
> On Fri, 7 Sep 2001 dhansen at zebra.net wrote:
> 
> > > I have two pieces of HB56SW3272ESK-5 "256MB
> Buffered EDO DRAM DIMM
> > > but in my Ultra AXi board they
> > > show up as 128MB sticks. I checked the bank
> layout and my configuration
> > > matched the AXi manual's admonitions...
> > 
> >    Your first problem is that those are 50ns
> chips.
> 
> Okay. I didn't know if that would be a problem. I
> haven't run into 50ns vs
> 60ns issues on the smaller pieces (32MB and 64MB)
> that I'm aware of.
> 
> >  Have you done any kind of troubleshooting yet?
> Like remove
> > the original pair and see if your new pair still
> behave the
> > same way. What does POST reveal? 
> 
> I have tried different banks, with and without other
> banks of RAM (256MB
> sticks, 64MB sticks), and they show up as 128MB each
> alone in either bank,
> with a pair of 256s in the other 11bit bank, and
> with a pair of 64s in the
> other 11bit bank.
> 
> POST reveals that they are detected as 11-bit column
> width in each
> condition. This was the case with or without other
> memory.
> 
> 	Probing Memory
> 	Group Info[0000.0000.0000.0003] :
> 0000.0000.0000.0000
> 	Group Info[0000.0000.0000.0002] :
> 0000.0000.0000.01a0
> 	Group Info[0000.0000.0000.0001] :
> 0000.0000.0000.0000
> 	Group Info[0000.0000.0000.0000] :
> 0000.0000.0000.0190
> 	Using 11-bit Column Addressing
> 	Done
> 	Clearing Memory... including Unix Retained
> Memory...Done
> 	MEM BASE = 0000.0000.3000.0000
> 	MEM SIZE = 0000.0000.1000.0000
> 	11-Column Mode Enabled
> 	
> 	Probing Memory Group #0 128 + 128 : 256 Megabytes
> 	Probing Memory Group #2 256 + 256 : 512 Megabytes
> 	
> My remaining guesses are that either the 50ns vs
> 60ns is a firm
> requirement on this size, or there's a single bank
> vs dual bank issue. I
> guess I'll keep saving up for a directly certified
> option for the 256s,
> and use these in my Ppro boxes.
> 	
> > Have you tried calling/emailing Hitachi
> Semiconductor to verify column
> > width on those chips? It would be nice if they
> work (I could use some
> > in mine), but so far it doesn't look like they
> match the required
> > specs.
> 
> I haven't, no. I'm a bit pessimistic about the
> likelihood of getting an
> answer on a three year old product from such a big
> company. 
> 
> Thanks for the response. 
> 
> --Rob
> Robert Novak, Indyramp Consulting *
> rnovak at indyramp.com * indyramp.com/~rnovak
>         "And it's been a long December and there's
> reason to believe
>            Maybe this year will be better than the
> last...." -- counting crows
> 
> _______________________________________________
> SunHELP maillist  -  SunHELP at sunhelp.org
> http://www.sunhelp.org/mailman/listinfo/sunhelp


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