[U-Boot-Users] New Yosemite (ppc440ep) sdram initiation.
Stefan Roese
sr at denx.de
Tue Dec 20 20:04:28 CET 2005
Hi Andre,
On Tuesday 20 December 2005 19:12, André 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
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