[U-Boot] Flash Erase and Write timeout for S29GL512P

[prakash bedge]

Hi,

I got the answers.

It was my negligence to miss the table. Sorry for taking your time.:)

Thanks & regards,
Prakash Bedge
On Tue, May 25, 2010 at 5:11 PM, Wolfgang Denk <wd at denx.de> wrote:

> Dear prakash bedge,
>
> In message <AANLkTilsrQ2jt8A2d9Lczd1uJHRa_3BcofQOjphinnyT at mail.gmail.com>
> you wrote:
> >
> > >> Be careful. 1024 s is chip erase time, but we use sector erase only,
> so
> > it's only 3.5 seconds.
> > It would be really helpful if you please explain how 3.5 seconds come;
> since
> > the S29GL512P datasheet says sector erase operation time is 0.5 seconds
> and
> > program operation time is 64 microseconds.
>
> The data sheet "S29GL-P MirrorBit® Flash Family" (see
> http://www.spansion.com/Support/Datasheets/S29GL-P_00_A12_e.pdf) reads
> in "Table 11.8 Erase And Programming Performance" (page 67):
>
> Parameter               Typ     Max     Unit    Comments
> Sector Erase Time       0.5     3.5     sec
>
> So the 0.5 seconds you are referring to is the "Typical program and
> erase times assume the following conditions: 25°C, 3.6 V VCC, 10,000
> cycles, checkerboard pattern."
>
> The 3.5 seconds I listed was " Under worst case conditions of -40°C,
> VCC = 3.0 V, 100,000 cycles."
>
> Obviously it is necessary to adjust this timeout for worst case
> conditions.
>
> >  What values I should put in my config file?
> > #define CONFIG_SYS_FLASH_ERASE_TOUT ??  /* Timeout for Flash Erase (in
> > ms) */
>
> I would use 5000 here (i. e. 5 seconds, which is 3.5 plus some safety
> margin).
>
> > #define CONFIG_SYS_FLASH_WRITE_TOUT ?? /* Timeout for Flash Write (in ms)
> */
>
> Here we have to calculate the timing based on the  Write Buffer
> Programming Time.
>
> > I seen canyonlands.h and I think it is also 64 MB flash.
> ...
> > #define CONFIG_SYS_FLASH_ERASE_TOUT 120000 /* Timeout for Flash Erase (in
> > ms) */
> > #define CONFIG_SYS_FLASH_WRITE_TOUT 500 /* Timeout for Flash Write (in
> > ms) */
>
> So - did you try using these values? And did they not work for you?
>
> > But I myself is not geting satsifed why I should use these values since
> they
> > are not as per the flash datasheet.
>
> They are timeouts, and they are most ptobably defensively set.
>
>
> I don't understand your problem. Keep in mind that these timeouts
> don't play any role as long as the chip is working normally - they
> apply only in the error case. And if your flash chip cannot be erased
> or programmed any more it does not really matter if you find out
> after 3.5 or after 5 or even after 12 seconds - you will lose much
> more time after that ;-)
>
> Best regards,
>
> Wolfgang Denk
>
> --
> DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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> That's what makes it a thing to be avoided.
>        -- Kirk, "A Taste of Armageddon", stardate 3193.0
>