New NAND flash die rev recommends 4 bit ECC

[Tim Barr]

I just got a notice from Micron that they are making changes to the
29F2G08/16 (2 Gbit SLC device). For instance, the 29F2G0816AAD is going
EOL this month and is being replaced by the MT29F2G08ABAEA. The problem
is that the new data sheet is recommending 4 bit per 526 byte ECC
instead of 1 bit per 526 byte ECC. As far as I can tell, the processor
we are using (AT91SAM9G20) only does 1 bit HW ECC and the software ECC
code for MTD is also 1 bit. The new NAND Flash die does have a HW 4 bit
ECC engine added in, which probably would need to have code written to
support it in order to be able to use it.

So, is anyone working on a 4 bit software ECC code or code modifications
to utilize the on chip HW ECC engine?

Right now we can use a part from an alternate vendor or do a lifetime
buy, but I am wondering if this is a trend as die size shrinks and other
vendors will soon require higher level ECC as well.

Tim Barr 
Development Engineer 
Multi-Tech Systems, Inc.