RE: point()/unpoint() questions + small cfi_cmdset_0001.c patch

Joakim Tjernlund
2002-06-17T16:22:48Z

>
> joakim.tjernlund@lumentis.se said:
> > I am mainly interested in using point() in scan.c to reduce mount
> > time. A quick and dirty hack to impl. point() gives me better a scan
> > time, from 4.43 sec to 3.53 sec, but this will probably go up a bit if
> > I do a proper impl. of point().
>
> Is this on your board with burst reads working? Are you using a cached
> mapping for point()?

Yes x 2

>
> > They do? I have not seen any evidence of this, do you happen to known
> > any perticular AMD device that does this?
>
> Looking at the AM29LV320D datasheet, page 26, under 'Sector Erase Command
> Sequence'...
>
> "Note that while the Embedded Erase operation is in progress, the system can
> read data from the non-erasing sector. The system can determine the status
> of the erase operation by reading DQ7, DQ6, DQ2 or RY/BY# in the erasing
> sector."
>
> (http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/23579a3.pdf)
>
> OTOH, the next page talks about the Erase Suspend command, which "allows
> the system to interrupt a sector erase operation and then read data from,
> or program data to, any sector not selected for erasure." So perhaps I was
> imagining it.
>

After a quick read I think it's NOT possible to read data without suspending an Erase
first.

Jocke