Serial RAM
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Posts: 46,084
At 07:24 AM 5/23/03 +0000, cchargin wrote:
>Hello all,
>
>I have been searching the net for serial RAM to use with the stamp (i
>have a BS2p24). The only offerings I can find are the Rampack B and a
>256 byte I2C chip from Philips.
>
>I have the Rampack B, but even running it at 19.2 (both the Rampack
>and the stamp recommend against 19.2) it is slow compared to
>read/write from an I2C eeprom.
>
>Even though I may never hit the 1 million write mark on an eeprom, I
>would prefer using external RAM for the frequently changing data in my
>project.
>
>Does anyone know of any 4 KB or larger serial RAM?
>
>As a side project I am going to see if I can interface a SRAM chip to
>the stamp using I2C IO expanders. Has anyone tried this already?
>
>Thanks in advance for suggestions and comments.
>
>Chuck Chargin Jr.
Chuck -
You may want to look at the ferro-electronic (FRAM) memory from Ramtron here:
http://www.ramtron.com/products/producthome.htm
As you will note 10 BILLION read/write cycles, 10 year data retention, and
"no wait" writes. Serial configurations and memory from 4K to 256K are
available. It appears samples are available.
Hope that helps.
Regards,
Bruce Bates
>Hello all,
>
>I have been searching the net for serial RAM to use with the stamp (i
>have a BS2p24). The only offerings I can find are the Rampack B and a
>256 byte I2C chip from Philips.
>
>I have the Rampack B, but even running it at 19.2 (both the Rampack
>and the stamp recommend against 19.2) it is slow compared to
>read/write from an I2C eeprom.
>
>Even though I may never hit the 1 million write mark on an eeprom, I
>would prefer using external RAM for the frequently changing data in my
>project.
>
>Does anyone know of any 4 KB or larger serial RAM?
>
>As a side project I am going to see if I can interface a SRAM chip to
>the stamp using I2C IO expanders. Has anyone tried this already?
>
>Thanks in advance for suggestions and comments.
>
>Chuck Chargin Jr.
Chuck -
You may want to look at the ferro-electronic (FRAM) memory from Ramtron here:
http://www.ramtron.com/products/producthome.htm
As you will note 10 BILLION read/write cycles, 10 year data retention, and
"no wait" writes. Serial configurations and memory from 4K to 256K are
available. It appears samples are available.
Hope that helps.
Regards,
Bruce Bates
Comments
I have been searching the net for serial RAM to use with the stamp (i
have a BS2p24). The only offerings I can find are the Rampack B and a
256 byte I2C chip from Philips.
I have the Rampack B, but even running it at 19.2 (both the Rampack
and the stamp recommend against 19.2) it is slow compared to
read/write from an I2C eeprom.
Even though I may never hit the 1 million write mark on an eeprom, I
would prefer using external RAM for the frequently changing data in my
project.
Does anyone know of any 4 KB or larger serial RAM?
As a side project I am going to see if I can interface a SRAM chip to
the stamp using I2C IO expanders. Has anyone tried this already?
Thanks in advance for suggestions and comments.
Chuck Chargin Jr.
http://www.mouser.com/index.cfm?handler=listproduct&&categoryid=95&lst_pcode
=5790
Original Message
From: "cchargin" <cchargin@e...>
To: <basicstamps@yahoogroups.com>
Sent: Friday, May 23, 2003 2:24 AM
Subject: [noparse][[/noparse]basicstamps] Serial RAM
> Hello all,
>
>
>
>
> I have been searching the net for serial RAM to use with the stamp (i
> have a BS2p24). The only offerings I can find are the Rampack B and a
> 256 byte I2C chip from Philips.
>
>
>
>
> I have the Rampack B, but even running it at 19.2 (both the Rampack
> and the stamp recommend against 19.2) it is slow compared to
> read/write from an I2C eeprom.
>
>
>
>
> Even though I may never hit the 1 million write mark on an eeprom, I
> would prefer using external RAM for the frequently changing data in my
> project.
>
>
>
>
> Does anyone know of any 4 KB or larger serial RAM?
>
>
>
>
> As a side project I am going to see if I can interface a SRAM chip to
> the stamp using I2C IO expanders. Has anyone tried this already?
>
>
>
>
> Thanks in advance for suggestions and comments.
>
>
>
>
> Chuck Chargin Jr.
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
(SRAM has infinite read/write cycles, but it
all goes away on power-off. EEPROM has a
fixed number of read/write cycles, but does
not go away on power off)
--- In basicstamps@yahoogroups.com, "Ricky Konvicka" <rkonvicka@h...>
wrote:
> Mouser has a bunch of ram of the I2c variety. Here is a few.
> http://www.mouser.com/index.cfm?
handler=listproduct&&categoryid=95&lst_pcode
> =5790
>
Original Message
> From: "cchargin" <cchargin@e...>
> To: <basicstamps@yahoogroups.com>
> Sent: Friday, May 23, 2003 2:24 AM
> Subject: [noparse][[/noparse]basicstamps] Serial RAM
>
>
> > Hello all,
> >
> >
> >
> >
> > I have been searching the net for serial RAM to use with the
stamp (i
> > have a BS2p24). The only offerings I can find are the Rampack B
and a
> > 256 byte I2C chip from Philips.
> >
> >
> >
> >
> > I have the Rampack B, but even running it at 19.2 (both the
Rampack
> > and the stamp recommend against 19.2) it is slow compared to
> > read/write from an I2C eeprom.
> >
> >
> >
> >
> > Even though I may never hit the 1 million write mark on an
eeprom, I
> > would prefer using external RAM for the frequently changing data
in my
> > project.
> >
> >
> >
> >
> > Does anyone know of any 4 KB or larger serial RAM?
> >
> >
> >
> >
> > As a side project I am going to see if I can interface a SRAM
chip to
> > the stamp using I2C IO expanders. Has anyone tried this already?
> >
> >
> >
> >
> > Thanks in advance for suggestions and comments.
> >
> >
> >
> >
> > Chuck Chargin Jr.
> >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the
Subject and
> Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >
bus. It is a 64k EEPROM.
I have PIC bacic pro code that should work with the stamp with a few
minor changes if you need it.
Jason
--- In basicstamps@yahoogroups.com, "Allan Lane" <allan.lane@h...>
wrote:
> SRAM! The page you called out is all EEPROM.
> (SRAM has infinite read/write cycles, but it
> all goes away on power-off. EEPROM has a
> fixed number of read/write cycles, but does
> not go away on power off)
>
> --- In basicstamps@yahoogroups.com, "Ricky Konvicka"
<rkonvicka@h...>
> wrote:
> > Mouser has a bunch of ram of the I2c variety. Here is a few.
> > http://www.mouser.com/index.cfm?
> handler=listproduct&&categoryid=95&lst_pcode
> > =5790
> >
Original Message
> > From: "cchargin" <cchargin@e...>
> > To: <basicstamps@yahoogroups.com>
> > Sent: Friday, May 23, 2003 2:24 AM
> > Subject: [noparse][[/noparse]basicstamps] Serial RAM
> >
> >
> > > Hello all,
> > >
> > >
> > >
> > >
> > > I have been searching the net for serial RAM to use with the
> stamp (i
> > > have a BS2p24). The only offerings I can find are the Rampack
B
> and a
> > > 256 byte I2C chip from Philips.
> > >
> > >
> > >
> > >
> > > I have the Rampack B, but even running it at 19.2 (both the
> Rampack
> > > and the stamp recommend against 19.2) it is slow compared to
> > > read/write from an I2C eeprom.
> > >
> > >
> > >
> > >
> > > Even though I may never hit the 1 million write mark on an
> eeprom, I
> > > would prefer using external RAM for the frequently changing
data
> in my
> > > project.
> > >
> > >
> > >
> > >
> > > Does anyone know of any 4 KB or larger serial RAM?
> > >
> > >
> > >
> > >
> > > As a side project I am going to see if I can interface a SRAM
> chip to
> > > the stamp using I2C IO expanders. Has anyone tried this
already?
> > >
> > >
> > >
> > >
> > > Thanks in advance for suggestions and comments.
> > >
> > >
> > >
> > >
> > > Chuck Chargin Jr.
> > >
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@yahoogroups.com
> > > from the same email address that you subscribed. Text in the
> Subject and
> > Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
> > >
I have looked into FRAM, but I can not find any place that will sell 1 or 2
chips, they all want me to buy a whole rail (I think it was 30 chips!) or I
have to buy a minimum of $50 from them (and they don't have any other cool
stuff to buy).
Anyone seen FRAM on a site that caters to hobbyists?
Ramtrons data sheet states that you would have to access the FRAM 30 times
a second for 10 years before it would wear out (the 32 KB chip). I guess I
could live with that. However, it still bothers me that the sun will burn
out in about 5 billion years. [noparse]:)[/noparse]
Chuck Chargin Jr.
At 03:18 AM 5/23/2003 -0400, you wrote:
>At 07:24 AM 5/23/03 +0000, cchargin wrote:
> >Hello all,
> >
> >I have been searching the net for serial RAM to use with the stamp (i
> >have a BS2p24). The only offerings I can find are the Rampack B and a
> >256 byte I2C chip from Philips.
> >
> >I have the Rampack B, but even running it at 19.2 (both the Rampack
> >and the stamp recommend against 19.2) it is slow compared to
> >read/write from an I2C eeprom.
> >
> >Even though I may never hit the 1 million write mark on an eeprom, I
> >would prefer using external RAM for the frequently changing data in my
> >project.
> >
> >Does anyone know of any 4 KB or larger serial RAM?
> >
> >As a side project I am going to see if I can interface a SRAM chip to
> >the stamp using I2C IO expanders. Has anyone tried this already?
> >
> >Thanks in advance for suggestions and comments.
> >
> >Chuck Chargin Jr.
>
>Chuck -
>
>You may want to look at the ferro-electronic (FRAM) memory from Ramtron here:
> http://www.ramtron.com/products/producthome.htm
>
>As you will note 10 BILLION read/write cycles, 10 year data retention, and
>"no wait" writes. Serial configurations and memory from 4K to 256K are
>available. It appears samples are available.
>
>Hope that helps.
>
>Regards,
>
>Bruce Bates
>
>
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
>from the same email address that you subscribed. Text in the Subject and
>Body of the message will be ignored.
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>Thanks for the reply,
>
>I have looked into FRAM, but I can not find any place that will sell 1 or 2
>chips, they all want me to buy a whole rail (I think it was 30 chips!) or I
>have to buy a minimum of $50 from them (and they don't have any other cool
>stuff to buy).
>
>Anyone seen FRAM on a site that caters to hobbyists?
You might want to check with Future/Active as they appear to be willing
to sell the FM24C256 in quantities of one of $ 9.50US each.
<http://www1.future-active.com/Comergent/en/US/adirect/future?cmd=OnlineOrdering\
PageDisplay>
Other than the FM25C256 larger quantities are required. Admittedly, this
may be a glitch in the Future/Active ordering system.
Alternative to that is asking for samples on the Ramtron web site as others
have done successfully before.
Bruce