Re: [ECOS] sdram size

Re: [ECOS] sdram size

[CARL.HUANG]

Hello, Jose:.

Thanks for yor reply. That's just what I want.
I read "PC SDRAM Serial Presence Detect (SPD) Specification "and almost know
the code.

But I still have a question: The slave address for SDRAM is oxA2 (from
hal_platform_setup.h). Why define this address to oxA2?  The slave address
for I2c is 0x02, why define this address to 0x02? I can't get answer from
the specification.

Waiting for your reply.

Regards,
Carl.

----------------------------------------------
Jose Souto wrote:

>If I understood your problem, Intel has a document named
>"PC SDRAM Serial Presence Detect (SPD) Specification"
>that explains everything about the eeprom inside SIMMs 
>and DIMMs modules. I have revision 1.2B of this document
>and it's very helpfull.

>Regards,
>Jose Luiz



carl.huang [üS½¨äh] wrote:
>> 
> >Hello, everyone.
> >
> >I'm new to eCos.
> >Now I'm working on 80321 chip, and read source code of eCos.
> >
> >I have a question: how do I get sdram size in initial code? From
>> hal_platform_setup.h(xscale\iq80321\current\include), I find that the
code
> >uses I2C interface to get sdram size and bank count . But how about
detail?
> >I mean how to address  eeprom/slave address, is there some document about
> >it?
> >
> >Thanks for any help.
> >
> >Regards,
> >Carl
> >
> >--
> >Before posting, please read the FAQ: http://sources.redhat.com/fom/ecos
> >and search the list archive: http://sources.redhat.com/ml/ecos-discuss

-- 
>Before posting, please read the FAQ: http://sources.redhat.com/fom/ecos
>and search the list archive: http://sources.redhat.com/ml/ecos-discuss

--
Before posting, please read the FAQ: http://sources.redhat.com/fom/ecos
and search the list archive: http://sources.redhat.com/ml/ecos-discuss

Re: [ECOS] sdram size

[Mark Salter]

>>>>> CARL HUANG writes:

> Hello, Jose:.
> Thanks for yor reply. That's just what I want.
> I read "PC SDRAM Serial Presence Detect (SPD) Specification "and almost know
> the code.

> But I still have a question: The slave address for SDRAM is oxA2 (from
> hal_platform_setup.h). Why define this address to oxA2? 

Actually, the comment in the code is wrong. The actual SDRAM_DEVID
value is 0xAE. The address is derived from fixed bits in hw and
the setting of switch S1D1. The default setting of S1D1 results in
an address of 0xAE for the SDRAM SPD. The code won't work for any
other settings of S1D1 as there is no way for the code to read the
switch settings. I have no idea why the switch is provided.

> The slave address
> for I2c is 0x02, why define this address to 0x02?

This is arbitrary and not necessary. The hal_platform_setup code does
not use the I2C controller in slave mode, so this address never comes
into play.

--Mark

-- 
Before posting, please read the FAQ: http://sources.redhat.com/fom/ecos
and search the list archive: http://sources.redhat.com/ml/ecos-discuss

Re: [ECOS] sdram size

[Jose Souto]

If I understood your problem, Intel has a document named
"PC SDRAM Serial Presence Detect (SPD) Specification"
that explains everything about the eeprom inside SIMMs 
and DIMMs modules. I have revision 1.2B of this document
and it's very helpfull.

Regards,
Jose Luiz

carl.huang [üS½¨äh] wrote:
> 
> Hello, everyone.
> 
> I'm new to eCos.
> Now I'm working on 80321 chip, and read source code of eCos.
> 
> I have a question: how do I get sdram size in initial code? From
> hal_platform_setup.h(xscale\iq80321\current\include), I find that the code
> uses I2C interface to get sdram size and bank count . But how about detail?
> I mean how to address  eeprom/slave address, is there some document about
> it?
> 
> Thanks for any help.
> 
> Regards,
> Carl
> 
> --
> Before posting, please read the FAQ: http://sources.redhat.com/fom/ecos
> and search the list archive: http://sources.redhat.com/ml/ecos-discuss

-- 
Before posting, please read the FAQ: http://sources.redhat.com/fom/ecos
and search the list archive: http://sources.redhat.com/ml/ecos-discuss

[ECOS] sdram size

[carl.huang [�S建�h]]

Hello, everyone.

I'm new to eCos.
Now I'm working on 80321 chip, and read source code of eCos.

I have a question: how do I get sdram size in initial code? From
hal_platform_setup.h(xscale\iq80321\current\include), I find that the code
uses I2C interface to get sdram size and bank count . But how about detail?
I mean how to address  eeprom/slave address, is there some document about
it?

Thanks for any help.

Regards,
Carl


-- 
Before posting, please read the FAQ: http://sources.redhat.com/fom/ecos
and search the list archive: http://sources.redhat.com/ml/ecos-discuss