[U-Boot-Users] New Yosemite (ppc440ep) sdram initiation.

[U-Boot-Users] New Yosemite (ppc440ep) sdram initiation.

[André Berggren]

Hello!

I have seen that the sdram initiation on Yosemite board has been changed lately. We have some memory problems on our custom board based on Bamboo. We are using the Yosemite initdram function but added a call to spd_sdram(). This helped a bit, but not all the way.
What are the benefits of using the sdram_tr1_set() instead of the alredy existing spd_sdram()?

Regards,
Andre
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[U-Boot-Users] New Yosemite (ppc440ep) sdram initiation.

[Stefan Roese]

Hi Andre,

On Tuesday 20 December 2005 19:12, Andr? Berggren wrote:
> I have seen that the sdram initiation on Yosemite board has been changed
> lately. We have some memory problems on our custom board based on Bamboo.
> We are using the Yosemite initdram function but added a call to
> spd_sdram().

Yosemite has onboard soldered DDR SDRAM chips and in therefore not using the 
spd_sdram() code at all. This is only used by board with DIMM modules and SPD 
EEPROM's. Please note that bamboo is an exception here, since it has one bank 
onboard soldered SDRAM and two DIMM slots with SPD EEPROM. Here the SPD 
information for the first onboard SDRAM bank is emulated.

> This helped a bit, but not all the way. What are the benefits 
> of using the sdram_tr1_set() instead of the alredy existing spd_sdram()?

None. Use (a) the spd_sdram() code (probably with modifications) for DIMM 
modules, or use (b) code like in yosemite.c with fixed init values (possibly 
with the tr1 calculation) for onboard soldered chips.

Best regards,
Stefan