[U-Boot-Users] I2C or DIMM?

[Stefan Roese <sr@denx.de>]

Hello G.Sibi,

On Monday 19 June 2006 03:40, Madhu Saravana Sibi Govindan wrote:
> I'm trying to debug u-boot on a custom board, which is similar to the
> ebony board. I see the following output on the serial console:

I assume you have done a board port to your custom board based on the ebony 
port, right? You should not using the ebony image itself, since most likely 
there are some differences in the board design.

> --------------------------------------------------
>
> U-Boot 1.1.4 (Jun 18 2006 - 20:35:07)
>
> CPU:   AMCC PowerPC 440GP Rev. C at 300 MHz (PLB=100, OPB=50, EBC=50 MHz)
>        Internal PCI arbiter disabled
>        32 kB I-Cache 32 kB D-Cache
> Board: Ebony - AMCC PPC440GP Evaluation Board
> I2C:   ready
> DRAM_MYDRAM:
> DRAM:  Calling spd_sdram
>  Within the SPD SDRAM function
> Trying a printf now
> ERROR: Unsupported DIMM detected in slot 0.
> Only DDR SDRAM DIMMs are supported.
> Replace the DIMM module with a supported DIMM.
>
> Read dimm_type = 255
> ### ERROR ### Please RESET the board ###
>
> --------------------------------------------------------------------
>
> (I have put in some additional debug statements in the u-boot code)
>
> It is not clear to me if the DIMM alone is the problem or if the I2C
> controller was not initialized correctly somehow (and so we are seeing
> a weird value from the EEPROM).  I'm going to try to put in a new DIMM
> and then, try the whole exercise again, but is there a way to check if
> the I2C controller is working fine?

Did you adapt the SPD EEPROM configuration (SPD_EEPROM_ADDRESS) to your board 
setup?

> I'm also going to read the other bytes from the EEPROM and see if they
> make sense.

Good. Does your board setup support 400 kHz I2C bus speed? If not please 
change it in your board config file.

Best regards,
Stefan