Now EEPROMs
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Posts: 46,084
In a message dated 12/29/2003 12:32:11 PM Eastern Standard Time,
allan.lane@h... writes:
> The statement:
> "It has 3 non-volatile cells; anything stored
> on the chip disappears when power is removed."
> thus does not make sense.
>
> What is the Parallax part number for the part
> you've been using? That would tell a lot.
Parallax part is 602-00008. The chip is X25640 - Xicor chip
The following statement was cut and pasted from page 7 of the data sheet for
the AT25HP512. Digikey calls this chip an EEPROM. You can go to their site
and check it out.
"The three bits, BP0, BP1, and WPEN are nonvolatile cells
that have the same properties and functions as the regular
memory cells (e.g. WREN, tWC, RDSR)."
Sid
[noparse][[/noparse]Non-text portions of this message have been removed]
allan.lane@h... writes:
> The statement:
> "It has 3 non-volatile cells; anything stored
> on the chip disappears when power is removed."
> thus does not make sense.
>
> What is the Parallax part number for the part
> you've been using? That would tell a lot.
Parallax part is 602-00008. The chip is X25640 - Xicor chip
The following statement was cut and pasted from page 7 of the data sheet for
the AT25HP512. Digikey calls this chip an EEPROM. You can go to their site
and check it out.
"The three bits, BP0, BP1, and WPEN are nonvolatile cells
that have the same properties and functions as the regular
memory cells (e.g. WREN, tWC, RDSR)."
Sid
[noparse][[/noparse]Non-text portions of this message have been removed]
Comments
EEPROM chip, made by Xicor. It should
hold it's data even though powered off.
Also, it's an 'SPI' (Serial Peripheral
Interface) chip, also known as a
'Three-Wire' interface, which can be
talked to using the BS2 'SHIFTIN/SHIFTOUT'
keywords.
The AT25HP512 is also an 8-pin chip, and
also uses an SPI interface. It is a
512 KBit EEPROM (64 KBytes).
The 'cells' you refer to are bits in the
"Write Status Register", and seem to control
write protection of parts of the EEPROM
memory. They are non-volatile, so your
write protection settings are preserved
when power is removed.
Now, what was your original question?
--- In basicstamps@yahoogroups.com, Newzed@a... wrote:
> In a message dated 12/29/2003 12:32:11 PM Eastern Standard Time,
> allan.lane@h... writes:
>
>
> > The statement:
> > "It has 3 non-volatile cells; anything stored
> > on the chip disappears when power is removed."
> > thus does not make sense.
> >
> > What is the Parallax part number for the part
> > you've been using? That would tell a lot.
>
>
> Parallax part is 602-00008. The chip is X25640 - Xicor chip
>
> The following statement was cut and pasted from page 7 of the data
sheet for
> the AT25HP512. Digikey calls this chip an EEPROM. You can go to
their site
> and check it out.
>
> "The three bits, BP0, BP1, and WPEN are nonvolatile cells
> that have the same properties and functions as the regular
> memory cells (e.g. WREN, tWC, RDSR)."
>
> Sid
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
allan.lane@h... writes:
> OK, the Parallax part is an 8-pin, 8K
> EEPROM chip, made by Xicor. It should
> hold it's data even though powered off.
> Also, it's an 'SPI' (Serial Peripheral
> Interface) chip, also known as a
> 'Three-Wire' interface, which can be
> talked to using the BS2 'SHIFTIN/SHIFTOUT'
> keywords.
I checked that this afternoon and the chip lost all data when power was
removed. I'll recheck that in the morning.
>
> The AT25HP512 is also an 8-pin chip, and
> also uses an SPI interface. It is a
> 512 KBit EEPROM (64 KBytes).
>
> The 'cells' you refer to are bits in the
> "Write Status Register", and seem to control
> write protection of parts of the EEPROM
> memory. They are non-volatile, so your
> write protection settings are preserved
> when power is removed.
I can't comment on that - I have not received the chip yet. Should be here
tomorrow then I'll check it out.
>
> Now, what was your original question?
I didn't really have a question. Someone said if the chip lost its data when
power was removed that it couldn't be couldn't be an EEPROM, and I was only
trying to point out what I had read and what I have observed. I'll get back
to you when I resolved the volatility question.
Sid
[noparse][[/noparse]Non-text portions of this message have been removed]
> Parallax part is 602-00008. The chip is X25640 -
> Xicor chip
> The following statement was cut and pasted from page
> 7 of the data sheet for
> the AT25HP512. Digikey calls this chip an EEPROM.
> You can go to their site
> and check it out.
Sid, I just opened the data sheet right from the
Parallax Website, and this is a quote from it:
"The X25640 is an electrically erasable, programmable,
read-only memory (EEPROM) device with 8192 bytes (8kB)
of storage. Like all EEPROMs, it retains data with
power off. It is intended for applications in which
data is read often and written infrequently, since
write operations gradually wear it out. Xicor says
that the X25640 will survive a minimum of 100,000
writes. Data stored in the EEPROM should remain intact
without power for 100 years or more."
You mention a AT25HP512 above...Perhaps this is the
wrong datasheet? the quotes above are from the
datasheet on Parallax's website with this particular
part. Hope this helps.
=====
Chris Savage
Knight Designs
324 West Main Street
Montour Falls, NY 14865
(607) 535-6777
http://www.knightdesigns.com
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