Rong Shen wrote:
> On Fri, May 29, 2009 at 6:05 PM, Robin Iddon <robin@edesix.com> wrote:
>
>> A word of caution on this:
>>
>>> 1. completely wipe the flash, data and spare area
>>>
>>>
>> We found that forcing erasure of bad block markers on Micron MLC FLASH part
>> (29F32G08QAA) left the block in a state where it could not be programmed
>> again (i.e. the bad block marker could not be set again). This is fair
>>
>
> Bad block marker is just non-FF byte/word in the spare area, if all
> bits are stuck in 1, the manufacturer wouldn't have had been able to
> mark it in the first place. Strange though. I could be wrong but it's
> more like a faulty chip or h/w issue.
>
In the factory they have more ways than one to program the bits I
suspect; ways that aren't available to you by the time the die is
packaged into the chip.
This happened on 6 out of 6 chips that we forcibly erased.
Robin
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