IMX53 Custom board, ram...

IMX53 Custom board, ram...

[andrea]

Hello everybody,

I would like to know what is the minimum requirement of ram that I need
to put on the board.
I saw for example that I can use MT41K128M16JT-125 XIT  from Micron.
it looks like it is a 16 bit ram. 
I know that for a project the ram usage is really low. It is a 16bit
ddr3. I didn't understand if I can use only 1 ram bank or if I need to
use (at least 2). On IMX53qsb there's 4 banks but reading:
http://git.freescale.com/git/cgit.cgi/imx/uboot-imx.git/tree/include/configs/mx53_loco.h?h=imx_v2009.08
it looks like that I can define CONFIG_NR_DRAM_BANKS to 1. 1 bank of
32bit? or I can use 1 bank of 16bit?

Thank you for the reading
Andrea

Re: IMX53 Custom board, ram...

[Ed Sutter]

Andrea,
A while back the first spin of our iMX6 based board had a bug that 
messed up the upper
16 bits or our 32-bit DRAM interface.  I was able to temporarily run 
this as a single bank
in 16 bit mode.  This was not with yocto however.  I would have to dig a 
bit to recall what I
had to change (I don't think it was the file you're pointing to); let me 
know if you
need that.
Ed
> Hello everybody,
>
> I would like to know what is the minimum requirement of ram that I need
> to put on the board.
> I saw for example that I can use MT41K128M16JT-125 XIT  from Micron.
> it looks like it is a 16 bit ram.
> I know that for a project the ram usage is really low. It is a 16bit
> ddr3. I didn't understand if I can use only 1 ram bank or if I need to
> use (at least 2). On IMX53qsb there's 4 banks but reading:
> http://git.freescale.com/git/cgit.cgi/imx/uboot-imx.git/tree/include/configs/mx53_loco.h?h=imx_v2009.08
> it looks like that I can define CONFIG_NR_DRAM_BANKS to 1. 1 bank of
> 32bit? or I can use 1 bank of 16bit?
>
> Thank you for the reading
> Andrea


-- 
Ed Sutter
Alcatel-Lucent Technologies -- Bell Laboratories
Phone: 908-582-2351
Email: ed.sutter@alcatel-lucent.com

Re: IMX53 Custom board, ram...

[andrea]

Thank you ED for your reply.

Actually I'm in the prototyping phase. so actually I'm just thinking
about how much ram I will need and for cost optimization I need to think
off which part I can safely remove. 
There's no hurry for that. After writing to the ML I found that in the
register ESDCTL that there's an option for setting the 16 bit.
I see that the register is used in this file:
http://git.freescale.com/git/cgit.cgi/imx/uboot-imx.git/tree/board/freescale/mx53_loco/flash_header.S?h=imx_v2009.08

so ideally if I set: REG_LD_AND_STR_OP(31, 0x000, 0xc3190000) to
REG_LD_AND_STR_OP(31, 0x000, 0xc3180000)

I should be able to set the micro DDR interface to 16 bit mode.

Only if you remember that. Looks this one a solution like the one you
did?

Thank you
Andrea

Il giorno ven, 27/03/2015 alle 14.06 +0100, Ed Sutter ha scritto:
> Andrea,
> A while back the first spin of our iMX6 based board had a bug that 
> messed up the upper
> 16 bits or our 32-bit DRAM interface.  I was able to temporarily run 
> this as a single bank
> in 16 bit mode.  This was not with yocto however.  I would have to dig a 
> bit to recall what I
> had to change (I don't think it was the file you're pointing to); let me 
> know if you
> need that.
> Ed
> > Hello everybody,
> >
> > I would like to know what is the minimum requirement of ram that I need
> > to put on the board.
> > I saw for example that I can use MT41K128M16JT-125 XIT  from Micron.
> > it looks like it is a 16 bit ram.
> > I know that for a project the ram usage is really low. It is a 16bit
> > ddr3. I didn't understand if I can use only 1 ram bank or if I need to
> > use (at least 2). On IMX53qsb there's 4 banks but reading:
> > http://git.freescale.com/git/cgit.cgi/imx/uboot-imx.git/tree/include/configs/mx53_loco.h?h=imx_v2009.08
> > it looks like that I can define CONFIG_NR_DRAM_BANKS to 1. 1 bank of
> > 32bit? or I can use 1 bank of 16bit?
> >
> > Thank you for the reading
> > Andrea
> 
> 
> -- 
> Ed Sutter
> Alcatel-Lucent Technologies -- Bell Laboratories
> Phone: 908-582-2351
> Email: ed.sutter@alcatel-lucent.com
> 

Re: IMX53 Custom board, ram...

[Ed Sutter]

No problem...
I found the file I changed.  Note that this was part of u-boot-2013.10,
so I don't know how much of this has changed since then.
The change was in board/freescale/imx/ddr/mx6d_1x_mt41j128.cfg...

DATA 4 0x021b0000 0x83180000
To change something in the MMDC.

IIRC, this is a file that is preprocessed by uboot tools to become part 
of the
initial image that is sucked in at initial bootload stages to configure 
the DDR.

HTH,
Ed

> Thank you ED for your reply.
>
> Actually I'm in the prototyping phase. so actually I'm just thinking
> about how much ram I will need and for cost optimization I need to think
> off which part I can safely remove.
> There's no hurry for that. After writing to the ML I found that in the
> register ESDCTL that there's an option for setting the 16 bit.
> I see that the register is used in this file:
> http://git.freescale.com/git/cgit.cgi/imx/uboot-imx.git/tree/board/freescale/mx53_loco/flash_header.S?h=imx_v2009.08
>
> so ideally if I set: REG_LD_AND_STR_OP(31, 0x000, 0xc3190000) to
> REG_LD_AND_STR_OP(31, 0x000, 0xc3180000)
>
> I should be able to set the micro DDR interface to 16 bit mode.
>
> Only if you remember that. Looks this one a solution like the one you
> did?
>
> Thank you
> Andrea
>
> Il giorno ven, 27/03/2015 alle 14.06 +0100, Ed Sutter ha scritto:
>> Andrea,
>> A while back the first spin of our iMX6 based board had a bug that
>> messed up the upper
>> 16 bits or our 32-bit DRAM interface.  I was able to temporarily run
>> this as a single bank
>> in 16 bit mode.  This was not with yocto however.  I would have to dig a
>> bit to recall what I
>> had to change (I don't think it was the file you're pointing to); let me
>> know if you
>> need that.
>> Ed
>>> Hello everybody,
>>>
>>> I would like to know what is the minimum requirement of ram that I need
>>> to put on the board.
>>> I saw for example that I can use MT41K128M16JT-125 XIT  from Micron.
>>> it looks like it is a 16 bit ram.
>>> I know that for a project the ram usage is really low. It is a 16bit
>>> ddr3. I didn't understand if I can use only 1 ram bank or if I need to
>>> use (at least 2). On IMX53qsb there's 4 banks but reading:
>>> http://git.freescale.com/git/cgit.cgi/imx/uboot-imx.git/tree/include/configs/mx53_loco.h?h=imx_v2009.08
>>> it looks like that I can define CONFIG_NR_DRAM_BANKS to 1. 1 bank of
>>> 32bit? or I can use 1 bank of 16bit?
>>>
>>> Thank you for the reading
>>> Andrea
>>
>> -- 
>> Ed Sutter
>> Alcatel-Lucent Technologies -- Bell Laboratories
>> Phone: 908-582-2351
>> Email: ed.sutter@alcatel-lucent.com
>>


-- 
Ed Sutter
Alcatel-Lucent Technologies -- Bell Laboratories
Phone: 908-582-2351
Email: ed.sutter@alcatel-lucent.com