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

bilahari bilahari_akkiraju at yahoo.com
Fri Oct 13 01:19:46 CEST 2006



Ben Warren <bwarren <at> qstreams.com> writes:

> 
> On Thu, 2006-10-12 at 15:11 +0200, Wolfgang Denk wrote:
> > In message <452E2DD0.3070409 <at> smiths-aerospace.com> you wrote:
> > >
> > > Back when I was a kid, all we had were ones.  To make a zero we had to 
> > 
> > They changed it to zeros later, because a zero is much more powerful.
> > For example, leading zeros can be very powerful, expecially when  you
> > employ  them  in  the  management  of big companies. [BTW: that's the
> > difference between commercial  and  scientific  notation:  scientists
> > tend  to  suppress  leading  zeros.]  And, to quote an ancient usenet
> > posting (sorry, the exact source is unknown to me):
> > 
> > Zero is an enigmatic value. It can mean success (fclose)  or  failure
> > (scanf).  It  can  mean  black  or  white. It can mean no permissions
> > (chmod) or all permissions (umask). It can mean now (setjmp) or later
> > (atexit). It can mean the beginning (lseek) or the end (read). It can
> > mean myself (getpgrp) or child (fork). It can mean  all  (kill's  1st
> > argument)  or  nothing  (kill's  2nd argument). It can mean `default'
> > (SIG_IGN) or `I don't care' (waitpid) or  `try  to  guess'  (strtol).
> > Indeed 0 lets you talk to God (setuid).
> > Verily is 0 all things to all people.
> 
> Obligatory follow-on from a long-forgotten source:
> 
> "The decline of the Roman Empire can be traced to the fact that, lacking
> zero, they were unable to return from their C programs"
> 
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> 

Thank you all , learned the The Transcedental Truth about zero,

>From spansion documentation :-

<<

When Flash memory is erased, all the bits in the 
erased area are set to a logical “1” (high signal level). 
Programming selectively changes bits to a logical 
“0” (Low signal level). Flash memory is traditionally 
programmed a single byte or word at a time and erased one 
sector at a time. Only an erase operation can return a “0” 
back to a “1”(erased) state.

For Floating-Gate technology, 
it is possible to re-program (or write over) a byte 
or word that has been previously programmed without 
first erasing the byte or word (as long as no attempt is 
made to program a “0” to a “1”). This re-programming of byte 
or word locations can be used to incrementally program 
individual bits to “0.” This incremental programming is 
useful to track the progress in multi-step programming 
schemes such as those used in a Flash File System.

>>






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