Re: Flash retention in uC at higher temps, experience?

On Fri, 13 Jun 2008 16:58:25 -0700, Joerg
<notthisjoergsch@[EMAIL PROTECTED]
> wrote:

>
>One could add some code so it re-flashes itself once in a while, that's 
>another option here. However, the device cannot lose power during that 
>brief period or it'll be really toast. So that would require large 
>enough electrolytics and some pre-regulator voltage monitoring. The 
>latter would require a relayout, bigger ECO and all that. Not a VP of 
>Engineering's favorite path, usually.

In a high radiation environment usually some ECC bits are stored in
each sector and with frequent sector reads you can detect if there are
flipped bits, correct the errors using the ECC and write back the
sector.

In this way, you know when to do the writeback and you can minimize
the (limited) number of refla****ng for a specific sector on the flash.

I assume this would also work with the data retention time problem at
elevated temperatures.

For a program written in assembly, it should not be a problem to
allocate a number of bytes for the ECC bits at the end of sector and
use a branch instruction to skip them, but this might be an issue, if
an HLL is used.

Paul