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Thread
2005-01-31 by gewitter2000
Hi! Has someone used the flash memory of the lpc21xx for eeprom purposes? Or is it more usefull to take an additive eeprom to the design? I only want to store some parameters. Thank you for feedback! Martin
2005-01-31 by Rajkumar Shetgar (RBIN/ECR2)
Hi,
Its always better to have EEPROM if you have frequent write cycles.
Flash used for code memory has roughly around 1000 write cycles, where
as if its data flash it has around 10,000+ write cycles. And EEPROM has
around 1 million write cycles.
Regards,
Raj
_____ From: gewitter2000 [mailto:martin@...] Sent: Monday, 31. January 2005 6:43 PM To: lpc2000@yahoogroups.com Subject: [lpc2000] Using flash memory instead of eeprom? Hi! Has someone used the flash memory of the lpc21xx for eeprom purposes? Or is it more usefull to take an additive eeprom to the design? I only want to store some parameters. Thank you for feedback! Martin _____ Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/lpc2000/ * To unsubscribe from this group, send an email to: lpc2000-unsubscribe@yahoogroups.com <mailto:lpc2000-unsubscribe@yahoogroups.com?subject=Unsubscribe> * Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service <http://docs.yahoo.com/info/terms/> . [Non-text portions of this message have been removed]
2005-01-31 by ntfreak2000
--- In lpc2000@yahoogroups.com, "Rajkumar Shetgar (RBIN/ECR2)" <Rajkumar.Shetgar@i...> wrote: > Hi, > > Its always better to have EEPROM if you have frequent write cycles. > Flash used for code memory has roughly around 1000 write cycles, where > as if its data flash it has around 10,000+ write cycles. And EEPROM has > around 1 million write cycles. > > Regards, > Raj > > _____ > > From: gewitter2000 [mailto:martin@c...] > Sent: Monday, 31. January 2005 6:43 PM > To: lpc2000@yahoogroups.com > Subject: [lpc2000] Using flash memory instead of eeprom? > > > > Hi! > > Has someone used the flash memory of the lpc21xx for eeprom purposes? > Or is it more usefull to take an additive eeprom to the design? I only > want to store some parameters. > > Thank you for feedback! > Martin > > > > > > _____ > > Yahoo! Groups Links > > > * To visit your group on the web, go to: > http://groups.yahoo.com/group/lpc2000/ > > * To unsubscribe from this group, send an email to: > lpc2000-unsubscribe@yahoogroups.com > <mailto:lpc2000-unsubscribe@yahoogroups.com?subject=Unsubscribe> > > * Your use of Yahoo! Groups is subject to the Yahoo! Terms of > Service <http://docs.yahoo.com/info/terms/> . > > > > > [Non-text portions of this message have been removed] I have used this technique with the ST STR7 devices, they have a write cycle of 100,000 and if combined with a linked list type structure to minimise using the same blocks it is a cheap method of eeprom emulation. Regards sjo
2005-01-31 by Richard
There are many serial flash devices (I Use SST25vf512)that guarantee 100K cycles and 100 years. Flash offers byte write and sector erase, while EEPROM offers both byte write and erase but are SLOW. Richard --- In lpc2000@yahoogroups.com, "gewitter2000" <martin@c...> wrote:
> > Hi! > > Has someone used the flash memory of the lpc21xx for eeprom purposes? > Or is it more usefull to take an additive eeprom to the design? I only > want to store some parameters. > > Thank you for feedback! > Martin
2005-01-31 by Robert Wood
Serial FRAM is available and not too outrageously priced now. Not as cheap as EEPROM, but if your project isn't cost sensitive it works a treat and you have unlimited life non-volatile memory. -------------------------------------------------------------- There are many serial flash devices (I Use SST25vf512)that guarantee 100K cycles and 100 years. Flash offers byte write and sector erase, while EEPROM offers both byte write and erase but are SLOW. Richard --- In lpc2000@yahoogroups.com, "gewitter2000" <martin@c...> wrote: > > Hi! > > Has someone used the flash memory of the lpc21xx for eeprom purposes? > Or is it more usefull to take an additive eeprom to the design? I only > want to store some parameters. > > Thank you for feedback! > Martin Yahoo! Groups Links
2005-02-01 by embeddedjanitor
AFAIK FRAM does not have unlimited life. It was around 10^6 cycles when I forst looked at it many years back and I believe it is now around 10^12 cycles, compared to around 10^5 cycles for EEPROM and flash. The smallprint though is that for EEPROM and flash, the endurance counts only the write cycles and not read cycles whereas FRAM endurance counts both. Because it is "just like RAM" once might be tempted to try place variables in FRAM or data items that you read frequently (data as well as code). In this case you could hit that 10^12 cycles pretty fast. With worst case code on an LPCxxx style device you could end up hitting the FRAM for more than 10^7 cycles per second, giving only a useful life of 10^5 seconds or just over a day. As always, design with your eyes open! --- In lpc2000@yahoogroups.com, Robert Wood <robert.wood@a...> wrote: > Serial FRAM is available and not too outrageously priced now. Not as cheap as > EEPROM, but if your project isn't cost sensitive it works a treat and you > have unlimited life non-volatile memory. > > -------------------------------------------------------------- > > There are many serial flash devices (I Use SST25vf512)that guarantee > 100K cycles and 100 years. Flash offers byte write and sector erase, > while EEPROM offers both byte write and erase but are SLOW. > > Richard > > --- In lpc2000@yahoogroups.com, "gewitter2000" <martin@c...> wrote: > > > > Hi! > > > > Has someone used the flash memory of the lpc21xx for eeprom purposes? > > Or is it more usefull to take an additive eeprom to the design? I only
> > want to store some parameters. > > > > Thank you for feedback! > > Martin > > > > > > > Yahoo! Groups Links
2005-02-01 by Varuzhan Danielyan
Dear embeddedjanitor, Please, open your eyes and have a look to www.ramtron.com. You will see, that many of their FRAMs now have not any write/read cycles limiting! Varuzhan
----- Original Message -----
From: embeddedjanitor
To: lpc2000@yahoogroups.com
Sent: Tuesday, February 01, 2005 8:25 AM
Subject: [lpc2000] Re: Using flash memory instead of eeprom?
AFAIK FRAM does not have unlimited life. It was around 10^6 cycles
when I forst looked at it many years back and I believe it is now
around 10^12 cycles, compared to around 10^5 cycles for EEPROM and
flash.
The smallprint though is that for EEPROM and flash, the endurance
counts only the write cycles and not read cycles whereas FRAM
endurance counts both.
Because it is "just like RAM" once might be tempted to try place
variables in FRAM or data items that you read frequently (data as
well as code). In this case you could hit that 10^12 cycles pretty
fast. With worst case code on an LPCxxx style device you could end up
hitting the FRAM for more than 10^7 cycles per second, giving only a
useful life of 10^5 seconds or just over a day.
As always, design with your eyes open!
--- In lpc2000@yahoogroups.com, Robert Wood <robert.wood@a...> wrote:
> Serial FRAM is available and not too outrageously priced now. Not
as cheap as
> EEPROM, but if your project isn't cost sensitive it works a treat
and you
> have unlimited life non-volatile memory.
>
> --------------------------------------------------------------
>
> There are many serial flash devices (I Use SST25vf512)that guarantee
> 100K cycles and 100 years. Flash offers byte write and sector
erase,
> while EEPROM offers both byte write and erase but are SLOW.
>
> Richard
>
> --- In lpc2000@yahoogroups.com, "gewitter2000" <martin@c...> wrote:
> >
> > Hi!
> >
> > Has someone used the flash memory of the lpc21xx for eeprom
purposes?
> > Or is it more usefull to take an additive eeprom to the design? I
only
> > want to store some parameters.
> >
> > Thank you for feedback!
> > Martin
>
>
>
>
>
>
> Yahoo! Groups Links
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[Non-text portions of this message have been removed]2005-02-01 by Robert Adsett
At 04:25 AM 2/1/05 +0000, embeddedjanitor wrote:
>AFAIK FRAM does not have unlimited life. It was around 10^6 cycles
>when I forst looked at it many years back and I believe it is now
>around 10^12 cycles, compared to around 10^5 cycles for EEPROM and
>flash.
They rate the low voltage devices as unlimited read/write cycles (I just
re-checked). As I recall, it is only within the last couple of years that
devices rated for that have been available. The high voltage (5V) devices
range from 10^10 to 10^12 read/write cycles. The write speed of FRAM
compared to ee is certainly an advantage but I wouldn't want to put a
millisecond clock in an older device.
Robert
" 'Freedom' has no meaning of itself. There are always restrictions,
be they legal, genetic, or physical. If you don't believe me, try to
chew a radio signal. "
Kelvin Throop, III2005-02-01 by 42Bastian Schick
> Because it is "just like RAM" once might be tempted to try place > variables in FRAM or data items that you read frequently (data as > well as code). In this case you could hit that 10^12 cycles pretty > fast. With worst case code on an LPCxxx style device you could end up > hitting the FRAM for more than 10^7 cycles per second, giving only a > useful life of 10^5 seconds or just over a day. Not quiet right. I just looked up on datasheet at Ramtron. The max. bus-freq. is 1E6 Hz for a 256KB FRAM. 20bits to read memory => max. 50000 reads/s The chip I look at has an endurance of 1E10, gives 200.000s ~= 138d. Also not forever, but slightly longer :-) > As always, design with your eyes open! Anyway a good hint :-) -- 42Bastian Schick
2005-02-01 by 42Bastian Schick
> AFAIK FRAM does not have unlimited life. It was around 10^6 cycles > when I forst looked at it many years back and I believe it is now > around 10^12 cycles, compared to around 10^5 cycles for EEPROM and > flash. For the FM23CL64 Ramtron claims Unlimited Read/Write cycles ! -- 42Bastian Schick
2005-02-01 by lpc2100_fan
Hi Martin, there has been a thread a while ago with the title "Partial Flash Programming" which you can use to do a search in the archive. In particular there was a posting from Philips_apps message # 2681 which give all the information necessary and some background why the flash can only be used in chunks of 16 bytes for EEPROM simulation and so on. hth, Bob --- In lpc2000@yahoogroups.com, "gewitter2000" <martin@c...> wrote:
> > Hi! > > Has someone used the flash memory of the lpc21xx for eeprom purposes? > Or is it more usefull to take an additive eeprom to the design? I only > want to store some parameters. > > Thank you for feedback! > Martin
2005-02-02 by mteversmith
--- In lpc2000@yahoogroups.com, "gewitter2000" <martin@c...> wrote: > > Hi! > > Has someone used the flash memory of the lpc21xx for eeprom purposes? > Or is it more usefull to take an additive eeprom to the design? I only > want to store some parameters. > > Thank you for feedback! > Martin Ho, I've implemented an eeprom emulation for a LPC2106 in my "T-Clock"- project. In the application it's just used to store two bytes for brightness (backlight LED PWM) and contrast (contrast voltage PWM AD-converter) values of the GLCD. You may find useful information in the files iap*.* and the linker-scripts in the archive available from http://www.siwawi.arubi.uni-kl.de/avr_projects/arm_projects/glcd_dcf77 One 8kByte memory-sector is reserved for "persistent storage" but the emulation is a "512Byte EEPROM" to minimize sector-erase. Basic approach: IAP and read-modify-write. HTH Martin Thomas