Reading SDRAM Memory Configuration via EEPROM on SIMM

Reading SDRAM Memory Configuration via EEPROM on SIMM

[James F Dougherty]

Does anyone know how to read an SDRAM SIMM EEPROM
to get the memory configuration data? I remember
there was a spec for this ... forgot the name...

You basically read I2C data bytes from an EEPROM
in a standard format.... PC's do this to find memory
settings..


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Re: Reading SDRAM Memory Configuration via EEPROM on SIMM

[Neil Russell]

Most SDRAM chip specs have enough stuff to figure this out.  I don't
have an address handy, but if you look at a chip and go to the
manufacturer's web site, ...

Also, LiMon has some code to do some of the SDRAM stuff.  It is written
in C, so it won't work on many CPUs, and it doesn't (yet) handle timing;
just geometry.  (C works on the 8260 before SDRAM is available because
you can use the internal RAM as a stack.)

	www.thinsys.com/limon.html


Neil.


On Thu, Nov 15, 2001 at 09:24:18PM -0800, James F Dougherty wrote:
>
> Does anyone know how to read an SDRAM SIMM EEPROM
> to get the memory configuration data? I remember
> there was a spec for this ... forgot the name...
>
> You basically read I2C data bytes from an EEPROM
> in a standard format.... PC's do this to find memory
> settings..

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Re: Reading SDRAM Memory Configuration via EEPROM on SIMM

[Jerry Van Baren]

In a URL :-)
   http://developer.intel.com/technology/memory/pc133sdram/spec/spdsd12b.htm

gvb


At 10:58 PM 11/15/01 -0800, Neil Russell wrote:

>Most SDRAM chip specs have enough stuff to figure this out.  I don't
>have an address handy, but if you look at a chip and go to the
>manufacturer's web site, ...
>
>Also, LiMon has some code to do some of the SDRAM stuff.  It is written
>in C, so it won't work on many CPUs, and it doesn't (yet) handle timing;
>just geometry.  (C works on the 8260 before SDRAM is available because
>you can use the internal RAM as a stack.)
>
>         www.thinsys.com/limon.html
>
>
>Neil.
>
>
>On Thu, Nov 15, 2001 at 09:24:18PM -0800, James F Dougherty wrote:
> >
> > Does anyone know how to read an SDRAM SIMM EEPROM
> > to get the memory configuration data? I remember
> > there was a spec for this ... forgot the name...
> >
> > You basically read I2C data bytes from an EEPROM
> > in a standard format.... PC's do this to find memory
> > settings..
>


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Re: Reading SDRAM Memory Configuration via EEPROM on SIMM

[Peter Barada]

>Does anyone know how to read an SDRAM SIMM EEPROM
>to get the memory configuration data? I remember
>there was a spec for this ... forgot the name...

Its called "Serial Presence Detect", and you can find the spec at:

http://developer.intel.com/technology/memory/pc133sdram/spec/spdsd12b.htm

--
Peter Barada                                   Peter.Barada@motorola.com
Wizard                                         781-852-2768 (direct)
WaveMark Solutions(wholly owned by Motorola)   781-270-0193 (fax)

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