Intel compatible flash device issue

MarekSk mareksk7 at
Thu Jun 24 13:40:54 EDT 2004

MarekSk wrote:
> Hi,
>  I have encountered a problem using M28W160CT flash chip as
>  LINUX character device. This chips is compatible with INTEL standard
>  command set.
>  Since the chip is locked after power-up, there is required to unlock
>  some blocks before write operation. Of course, this can be done
>  from any application using MEMUNLOCK command.
>  Once the MEMUNLOCK command is executed (without any error)
>  the flash chip remains in the "command" state.
>  This state after MEMUNLOCK blocks any read access to data stored
>  in the flash.
>  Reviewing the cfi_cmdset_0001.c file I have found that single block
>  (un)lock algorithm (do_xxlock_oneblock) is different from these
>  described in the following documents:
>  - STM M28W160CT datasheet (figure 22)
>    <>
>  - Intel 28F160C3 datasheet (figure 20)
>    <>
>  It seems that there should be issued the reset command (0xff) just
>  after lock (0x01)/unlock (0xd0) command.

The above mentioned chips work with CFI command set #3.
Therefore, I have prepared the patch for un/lock commands from the
set #3 to one who is interested in it.


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