Lpc2000

Dear Robert,

You missed my point.

You suggest that the EE_Demo is for users who know how to use EEPROM
to store small amounts of data, but do not know how to do this using
LPC FLASH memory.  If they did, they would not need your interface.

It is precisely such an audience that needs to be forewarned that
FLASH and EEPROM have very difference endurance cycles.  I would
recommend you point this out clearly in the documentation if you have
not done so.

The interface you provide hides the underlying implementation, making
EEPROM and FLASH look the same, and for those who do not bother doing
this on their own.  This is why I say while it may be a good academic
exercise for students, it is of dubious value for real world use.

Using flash to store small (or large amounts) amounts of read-write
data is not a new concept.

To put it bluntly, you may think you are saving money by doiong away
with EEPROM and using your EEPROM over FLASH interface, until your
product is in the field and you discover how different the endurance
cycles differnt.

The reason for your "demo" is to show how to work around ECC bug in
LPC flash implementation, because it ECC is not as transparent is it
was supposed to be.   Am I right?

Jaya

--- In lpc2000@yahoogroups.com, "philips_apps" <philips_apps@y...> wrote:
>
> What is the purpose of an EEPROM? To hold a small amount of 
> reprogrammable data, that can be organized anything from bit-wise to 
> big structures. Usually it gets reprogrammed frequently. So, 
> reprogramming cycles are very important. Most dedicated EEPROMs have 
> more than 1 Mio reprogramming cycles, the flash on the LPC2000 
> devices just 100k. 
> 
> Assuming it is data that needs to be written every day when powering 
> down a machine at the end of the workday. That makes approx. 300 
> days a year and this should happen for 20 years, gives 6000 cycles, 
> emulating the EEPROM by using Flash should be just fine.
> 
> The purpose of the EE_Demo is to help our customers to write small 
> set of data into the Flash and saving the expense of an EEPROM. It 
> does not imply anything but the facts it is stating, a customer 
> might be able to use the Flash and get by without an EEPROM. You are 
> right, Flash and EEPROM are different, nevertheless, a Flash can 
> provide enough functionality to replace the function of an EEPROM. 
> So, for those many customers that do not want to spend the extra 
> money for an EEPROM, this application note can save some money, if 
> you need a "real" EEPROM, please feel free to attach it to the SPI 
> or I2C interface. 
> 
> Robert