[U-Boot-Users] MPC850, read FLASH manufacturer ID, Mxu Board

Wolfgang Denk wd at denx.de
Wed Feb 26 12:26:53 CET 2003

In message <3E5C9D59.2000808 at esk.fhg.de> you wrote:
> The VxWorks boot prompt command uses "sth" assembler command to write
> to flash and the u-boot flash_get_size() command uses "stw" assembler
> code.
> - Could someone explain why "sth" works and "stw" doesn't work in
>    our case?

You have to adjust the flash driver to your hardware. It  depends  on
bus  width  (8, 16, 32 bit?), number of flash chips / flash width per

Comon configurations are:

	 8 bit bus - 1 flash chip   8 bit
	16 bit bus - 2 flash chips  8 bit
		   - 1 flash chip  16 bits
	32 bit bus - 4 flash chips  8 bit
		   - 2 flash chips 16 bits

The TQM8xxL which you took as model uses a 32 bit bus  with  2  flash
chips  at  16 bit. It uses word accesses to write to both flash chips
at the same time.

You seem to have a different configuration, probably using a  16  bit
bus with either 1 flash chip (16 bit) or 2 flash chips (2 x 8).

This is something you have to find out, and understand, yourself.  Or
hire someone to do it for you. But it's impossible for me here on the
list to guess what your hardware looks like.

It is dangerous to copy code without thinking what it does.

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
No, I'm not going to explain it. If you  can't  figure  it  out,  you
didn't want to know anyway... :-)
                   - Larry Wall in <1991Aug7.180856.2854 at netlabs.com>

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