--- In , "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

An Engineer's Guide to the LPC2100 Series

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 , "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

Hi Owen / Martin, Maybe it's also worth to point out that you can emulate EEPROM closer by "spreading" the data in Flash, and leaving markers - although I'm not sure with the sector sizes involved, it would have to be large amounts to make it worth. If you have plenty spare Flash, you can get closer to EEPROM by typically using 4-8 times the amount of Flash, and emulate EEPROM like that. (ie. for 4 K EEPROM you'd need at least 16K Flash) If you need further info, send me a direct Email. Cheers, Kris > --- In , Owen Mooney <ojm@s...> wrote: > > Yes I have. Its easy, but you have to use up a whole page (unless > you read - modify - write) I had lots of spare flash and was typically > saving a configuration just a few times so these limitations didn't > matter. > > > > Code using IAP instructions below. > > > > Accessing the stored structure is just a direct memory access. > > > > The write cycle limitations have been well documented by those > willing to offer an opinion but not answer your question !!! > > > > Owen Mooney > > > > #define IAP_LOCATION 0x7ffffff1 > > > > void savesetup(struct SETUP *setup){ > > typedef void (*IAP)(unsigned int [],unsigned int[]); > > unsigned int command[5]; > > unsigned int result[2]; > > IAP iap_entry; > > __ARMLIB_disableIRQ(); > > iap_entry=(IAP) IAP_LOCATION; > > // get part ID > > command[0]T; > > result[0]=0; > > iap_entry(command, result); > > // result in result[1] > > // prepare to erase > > command[0]P; > > command[1]; > > command[2]; > > iap_entry(command, result); > > if (result[0] != 0) goto error; > > // erase > > command[0]R; > > command[1]; > > command[2]; > > command[3]745; > > iap_entry(command, result); > > if (result[0] != 0) goto error; > > // prepare to program > > iap_entry=(IAP) IAP_LOCATION; > > command[0]P; > > command[1]; > > command[2]; > > iap_entry(command, result); > > if (result[0] != 0) goto error; > > // program > > command[0]Q; > > command[1]=0x1C000; > > command[2]=(int)setup; > > command[3]Q2; > > command[4]745; > > iap_entry(command, result); > > if (result[0] != 0) goto error; > > __ARMLIB_enableIRQ(); > > return; > > error: > > __ARMLIB_enableIRQ(); > > printf("bum"); > > } > > > > > > 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 > > a.. To

Hi Owen, Yes, this helps a lot. Thank you! Martin --- In , Owen Mooney <ojm@s...> wrote: > Yes I have. Its easy, but you have to use up a whole page (unless you read - modify - write) I had lots of spare flash and was typically saving a configuration just a few times so these limitations didn't matter. > > Code using IAP instructions below. > > Accessing the stored structure is just a direct memory access. > > The write cycle limitations have been well documented by those willing to offer an opinion but not answer your question !!! > > Owen Mooney > > #define IAP_LOCATION 0x7ffffff1 > > void savesetup(struct SETUP *setup){ > typedef void (*IAP)(unsigned int [],unsigned int[]); > unsigned int command[5]; > unsigned int result[2]; > IAP iap_entry; > __ARMLIB_disableIRQ(); > iap_entry=(IAP) IAP_LOCATION; > // get part ID > command[0]T; > result[0]=0; > iap_entry(command, result); > // result in result[1] > // prepare to erase > command[0]P; > command[1]; > command[2]; > iap_entry(command, result); > if (result[0] != 0) goto error; > // erase > command[0]R; > command[1]; > command[2]; > command[3]745; > iap_entry(command, result); > if (result[0] != 0) goto error; > // prepare to program > iap_entry=(IAP) IAP_LOCATION; > command[0]P; > command[1]; > command[2]; > iap_entry(command, result); > if (result[0] != 0) goto error; > // program > command[0]Q; > command[1]=0x1C000; > command[2]=(int)setup; > command[3]Q2; > command[4]745; > iap_entry(command, result); > if (result[0] != 0) goto error; > __ARMLIB_enableIRQ(); > return; > error: > __ARMLIB_enableIRQ(); > printf("bum"); > } > 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 > ____________

> 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

> 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

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, III

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: 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 , 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 , "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 ------ Yahoo! Groups Links a.. To

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 , 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 , "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

Re: Using flash memory instead of eeprom?
Re: Using flash memory instead of eeprom?
Re: Using flash memory instead of eeprom?

Yes I have. Its easy, but you have to use up a whole page (unless you read - modify - write) I had lots of spare flash and was typically saving a configuration just a few times so these limitations didn't matter. Code using IAP instructions below. Accessing the stored structure is just a direct memory access. The write cycle limitations have been well documented by those willing to offer an opinion but not answer your question !!! Owen Mooney #define IAP_LOCATION 0x7ffffff1 void savesetup(struct SETUP *setup){ typedef void (*IAP)(unsigned int [],unsigned int[]); unsigned int command[5]; unsigned int result[2]; IAP iap_entry; __ARMLIB_disableIRQ(); iap_entry=(IAP) IAP_LOCATION; // get part ID command[0]T; result[0]=0; iap_entry(command, result); // result in result[1] // prepare to erase command[0]P; command[1]; command[2]; iap_entry(command, result); if (result[0] != 0) goto error; // erase command[0]R; command[1]; command[2]; command[3]745; iap_entry(command, result); if (result[0] != 0) goto error; // prepare to program iap_entry=(IAP) IAP_LOCATION; command[0]P; command[1]; command[2]; iap_entry(command, result); if (result[0] != 0) goto error; // program command[0]Q; command[1]=0x1C000; command[2]=(int)setup; command[3]Q2; command[4]745; iap_entry(command, result); if (result[0] != 0) goto error; __ARMLIB_enableIRQ(); return; error: __ARMLIB_enableIRQ(); printf("bum"); } 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 ____________

Re: Subject: Using flash memory instead of eeprom?
Re: Subject: Using flash memory instead of eeprom?