2008-04-11 15:01:46     Mobile DDR Support

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2008-04-11 15:01:46     Mobile DDR Support

Kris Dickie (CANADA)

Message: 54115    I have a custom 548 board with mobile DDR on it. I can load a very stripped down u-boot  (ie. just spi/eeprom/ and a few commands) into SPI flash and get it to boot, but it typically takes many resets, as u-boot often crashes. The same bootloader runs without any errors or crashes on the EZKIT.

 

I have narrowed the bootup crashes down to accesses to memory (ie. the mem operations env_relocate), and once finally running with a prompt, running mtest yields errors on almost every readback (usually off by just 1 bit).

 

I run a 40 MHz clock with VCO=13, CCLKDIV=1, SLCKDIV=4 (520 MHz CCLK and 130 MHz SCLK), and I know our local ADI rep. has said that mobile DDR is spec'ed out to run at only 80 MHz reliably, (anomaly 5000377) however I cannot get the processor to get past the initcode() stage when I have set SCLK= 80 MHz, you would think at least keeping the register defaults VCO=10, CCLKDIV=1, SCLKDIV=5 would yield something bootable past initcode(), but it does not, any ideas? I have tested two boards, and narrowed down that it is not a bad solder or pin producing the memory error. Also, I have tested the 548 EZKIT with SCLK= 80Mhz, and same thing, won't go past initcode().

 

Sorry, this maybe should be in the uboot thread, but others using mobile DDR may have similar issues in bootloader or kernel.

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2008-04-11 17:16:09     Re: Mobile DDR Support

Kris Dickie (CANADA)

Message: 54122    Im guessing that the DDR refresh rates etc, programmed in DDRCTRL0 need to be updated when the SCLK changes, so I will test this out and inform. Also, I realized i missed setting bit 5 on EBIU_RSTCTL for mobile DDR operation.

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2008-04-11 17:49:53     Re: Mobile DDR Support

Mike Frysinger (UNITED STATES)

Message: 54126    if memory isnt sane, then it doesnt matter terribly much how far u-boot makes it once it tries using external memory

 

i'd and a test similar to mtest at the end of the initcode and have it spit the results out the uart

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2008-04-13 01:32:34     Re: Mobile DDR Support

Robin Getz (UNITED STATES)

Message: 54153    Kris:

 

Yeah, this is tracked in the bug tracker:

http://blackfin.uclinux.org/gf/project/uclinux-dist/tracker/?action=TrackerItemEdit&tracker_id=141&tracker_item_id=3726

 

http://blackfin.uclinux.org/gf/project/uclinux-dist/tracker/?action=TrackerItemEdit&tracker_item_id=3985

 

-Robin

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