Lpc2000

To be fair to Philips, they generally describe the on-board flash 
as "program memory", and it's clear that this is very much its 
intended purpose.

It is kind of tempting though to use it as general purpose EEPROM, 
but as Peter points out it's a long way from this.

In our case it was a straightforward tradeoff: the cost of 
developing and testing usable and robust EEPROM emulation software 
far exceeded the cost of the external EEPROM (apart from concerns 
about lifetime, as we write quite often). In the general case, I 
think your volumes would have to be very high (100k+ ?) before it 
would make much sense.

In some specific cases (e.g. writing a very occasional block of data 
that rarely or never gets erased) it can make sense, though: it's 
really a matter of looking at particular requirements and the time 
and effort required to implement them.

Brendan

--- In lpc2000@yahoogroups.com, Peter Jakacki <peterjak@...> wrote:
>
> Bryce Schober wrote:
> I have used program flash on other micros for data eeprom before 
but I 
> really don't like doing it as I increase the risk that the program 
could 
> become corrupted due to a software bug. In which case I wished 
that I 
> had just spent the buck.
> 
> When it comes to the LPC21xx I just would not even consider doing 
this 
> at all and I would rather spend the buck on a safe n sure serial 
eeprom. 
> However, that being said, I do backup blocks of data from RAM but 
this 
> is usually done only infrequently.
> 
> When considering the internal flash for eeprom use, the limits of 
16 
> bytes at a time for programming and need for large sector erase, 
vpp 
> generator start-up time etc should be sounding alarm bells. The 
voice in 
> your head should be going "NO WAY".
>