[U-Boot-Users] Memory problems with u-boot in EP852T board (Embedded Planet)

Wolfgang Denk wd at denx.de
Mon Apr 26 14:54:37 CEST 2004

In message <61ACE46D4D8B6B4C887FDDA78DF9886B083F5D at ex03.commil.com> you wrote:
> 1. Does CFG_MAX_FLASH_SECT  71(the num of sectors in one AMD chip)
> includes both chips ?

I guess both chips are operated in parallel, to have a 2 x  16  =  32
bit  wide  data bus; if this assumpion is correct, then the answer is

>     Which means does the u-boot/cpu see a 1 big flash of 8MB 32 bits bus

Youmust answer this yourself.  I  dopn't  know  your  hardware.  [But
chances are 99% that this is the case.]

> with doubled size sector? instead of a 64KB size sectors(in a single AMD
> chip), a 128KB size   
>     sectors?


> 2. According to the EP852T board user manual, the 8MB flash base address
> starts at 0xff800000 (=CFG_FLASH_BASE) .

This is just documentation. YOu can always define your own memory map
if you see any advantage in doing so.

> 1. Although the flash prelim and mask are conifgured as defined in the
> EP board manual, when running the u-boot flash_get_size() 
>    it fails on reading Manufacturer ID.

Probably your flash driver is not configured for 2 x 16 bit devices.

>    When i bypass the flash_get_size and choose manually, in the code,
> the AM29LV320B flash and its sectors(71) and size(8MB),
>   later, in the u-boot monitor i cannot erase the flash (none of the
> u-boot erase options work), but i can only read its sectors content .

Probably your flash driver is not configured for 2 x 16 bit devices.

>   i also see that most of its sectors are detected as protected :(using
> the "flinfo" command)

Probably your flash driver is not configured for 2 x 16 bit devices.

> 2. The second problem i have is with the SDRAM operation .
>     The SDRAM seems to work(read and write are possible) only when i use
> CFG_PRELIM_OR_AM   0xfc000000,
>     although CFG_PRELIM_OR_AM should be configured to 0xff000000 , for
> 16MB SDRAM OR mask .

Probably other parameters are wrong, like the numbers of columns.

> ------_=_NextPart_001_01C42B86.A35BCDF2
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Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
What we anticipate seldom occurs;  what  we  least  expect  generally
happens.                                          - Bengamin Disraeli

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