Hi, Jerry,
Took your advice on flash addresses I should put into my command sequences with my current flash configuration (2 16-bit spansion s29GL064M chips interleaved to form 32-bit flash system). You pointed me to the right direction, thanks. Although I couldnt succeed in manual manipulation of flash, I am able to do it programatically (I downloaded a free low level driver provided by spansion and used it with my code). And it works fine, just like u-boot driver (cfi_flash.c). For anyone interested here is the link http://www.spansion.com/support/drivers_software/index.html
But one thing that doesnt work with my code and also with u-boot is that if I want to write two different values to the same flash locationconsecutively ( for example when I try to write 0x12 to flash address 0xff000000 and then write 0x34 to same flash address, u-boot gives me a message "flash not erased". My driver makes the program simply loop forever in a status register polling loop, I guess).
Is it something natural with flash programming ?. Should I always erase the whole sector before I re-program a location ? (doesnt sound like a good approach to me), is it not possible to write consecutively as with the conventional memory?
Thanks for the help and the directions
Bilahari