It could be from the start of a sector or CRC bytes but you would not
get them unless you are starting or stopping reads incorrectly.

Look for 0xFE in sd_data_byte'get()

Matt.

On Apr 28, 10:27 am, Sebastien Lelong <[email protected]>
wrote:
> Hi Matt, guys,
>
> I'm experiencing troubles implementing Minix filesystem over sd card. For
> some reason I can't  find, reading a big file (64MB) always gets stuck at
> the exact same location.
>
> I can't dive into Minix internals here, but filesystem is divided into 1KB
> block. Addresses where data actually lies are located on zones. When files
> is becoming large, you need to read some indirect data addresses (and even
> double indirect). So, when reading content, block addresses are read like
> this:
>
> block 0x3250 => 1KB data
> block 0x3251 => 1KB data
> block 0x3252 => 1KB data
> ...
> then nothing :(
>
> Digging this, I discovered the data location address isn't 0x3253 as
> expected (I checked with hexdump, this is the next data location for sure),
> but, instead, it is 0x3253FEFF ! This means while reading address on sd
> card, it seems some sd card internal bytes were returned, instead of actual
> data (0xFE and 0xFF are some kind of meaningful internal bytes IIUC).
>
> Does this make sense to you ? I really can't figure out why it occurs at
> this time. And it is always, strictly always the same location.
>
> TIA
> Cheers,
> Seb
>
> 2011/4/21 Sebastien Lelong <[email protected]>
>
>
>
> > Hum... I didn't realize this difference...
>
> > :)
>
> > Seb
>
> > 2011/4/21 Oliver Seitz <[email protected]>
>
> >> > I perfer the RAM due to fast
> >> > read/write speeds, high endurance. Does
> >> > SST have any serial ram? What is the write speed of SST
> >> > flash?
>
> >> I was about to write that... But then I realized that both chips were pin
> >> compatible, so the PCB would work with ram or flash ;-)
>
> >> Greets,
> >> Kiste- Hide quoted text -
>
> - Show quoted text -

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