[U-Boot-Users] Can I write to flash using mw command

[bilahari akkiraju <bilahari_akkiraju@yahoo.com>]

Hello, 

 ->  On my target board I have a spansion GL064M flash
device. 

 -> The flash base address is 0xff000000. 

 -> I have read the data sheet for the device and
noted down the erase and write command sequences for
the device.

 -> I cannot erase, write to flash by implementing the
appropriate command sequences with mw (memory write )
command provided by u-boot that came with my sdk
(u-boot 1.1.4).

 For example 

  For erasing sector 0xff000000 I typed the following
sector erase command sequence (as per data sheet) at
u-boot prompt

 mw.b 0xff000555 0xAA
 mw.b 0xff0002AA 0x55
 mw.b 0xff000555 0x80
 mw.b 0xff000555 0xAA
 mw.b 0xff0002AA 0x55
 mw.b 0xff000000 0x30

 For writing to address 0xff000000 I typed the
following write command sequence (as per data sheet)
at the u-boot prompt.

mw.b 0xff000555 0xAA
mw.b 0xff0002AA 0x55
mw.b 0xff000555 0xA0
mw.b 0xff000000 0x12  ; value 0x12
mw.b 0xff000001 0x34  ; value 0x34
mw.b 0xff000000 0xF0  ; reset (I do it as u-boot
driver cfi_flash.c does it )


  -> After doing all this , when I do a memory dump
using md.b 0xff000000 , to my frustration I see that
nothing at all has happend to the flash.

 I am sure I am missing something small or may be I am
doing a completely wrong thing. I am more of a
computer science guy and new to chip programming. Any
suggestions, ideas or comments would be very helpful.

Thanks you all


Bilahari

 


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