[U-Boot-Users] DDR SDRAM in DIMM module for Yosemite-like PPC440EP board.

Leonid Leonid at a-k-a.net
Fri Oct 20 17:57:01 CEST 2006


On Friday, October 20, 2006 4:59 AM Stefan Roese wrote:
> If you are using DIMM modules, please don't use the board specific DDR 
> init code of the Yosemite, but the cpu specific DDR init code für DDR DIMM 
> modules, like the other 440 AMCC eval boards do (e.g. ocotea, bamboo).

[Leonid] I'll try to do that, thank you. Yet I probably didn't make myself clear: I connect BDI2000 first whose configuration file can initialize all registers (though one can skip directly to code by "reset run" BDI command). Neither code is running in this moment (except BDI's firmware) and I expect that if BDI config file is correct, SDRAM will be available even BEFORE u-boot code takes over, but it's not: Mode Register Set Command never get completed and WORKSPACE command from config file doesn't work. I'll take a look into BDI config files for other AMCC boards - like ocotea & bamboo if I'll be able to find them.
 
> Please modify your U-Boot configuration to use the cpu/ppc4xx/spd_sdram.c 
> code. The following lines should be added to your board config file (with 
> the correct I2C addresses of course):

> #define CONFIG_SPD_EEPROM     1        /* Use SPD EEPROM for setup     */
> #define SPD_EEPROM_ADDRESS {0x53,0x52}  /* SPD i2c spd addresses        */

[Leonid] You mean to use option G or H to read bootstrap from serial EEPROM? Or some another exercise with EEPROM I must do because I'm using DIMM module? I'll read this code to see what it does.

> Yes, a HW problem is also possible. What termination are you using? Did 
> you "clone" the HW design from some IBM/AMCC eval boards?
[Leonid] The board was supposed to be cloned from Yosemite so it was complete surprise for me when I learnt that HW folks put memory into DIMM module. Can you recommend what exactly should I ask them to look into - what "termination" do you mean? 

Best regards,
Leonid.




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