Lpc2000

Samuel...

>["SR" <emddjava@y...> wrote:]
> ... if anyone has any ideas on how I can add a filesystem
> to 2138 or the 2294's flash portion, i am thinking of FAT32
> is there any material/book I can get for a comprehensize 
> study on this, I need to basically do relative addressing when 
> logging or calling the log file, any help will be appreciated 

As I recall, FAT32 disk partitions need a minimum 'disk' size of 260MB
(that's MEGAbytes).  The old FAT12 is good for 'disks' up to about
16MB;  I believe FAT16 is good for 16MB to around 2GB. 

Given the internal flash of the 2294 (and prob the 2138) = 256kB,
you'd want to use FAT12. 

I believe there was an open FAT12 implementation in a fairly recent 
Circuit Cellar magazine article in the last 6 months. Not sure; this
may have been a read-only implementation.

For a commercial product, you'll likely use one of various commercial
vendors' file systems out there (NucleusFILE, SMX, Fusion, etc.) with
licensing, etc. - prob source code and linkable library versions are
out there.

You may have to figure out flash wear-levelling, flash erase block
size, and reuse strategies yourself if the filesystem isn't
flash-aware (or is only set up to talk to consumer flash devices like
SD/MMC, CF, etc. which manage this aspect inside the card).

A basic FAT filesystem has format, open, close, delete, rename, and
various read & write calls. These can be hooked, with some effort, and
tied into C library functions - or you just use the FAT library calls
instead. The basic FAT filesystems are used to working with block
devices and expect to call a read or write function that reads/writes
1...256 blocks of 512 bytes each (usu sector size, but this can be
changed).  You'll have to play w/cluster size vs erase block size.

If DOS compatibility is not needed (likely) there are probably better
filesystems to use  ---- unless your LPC2xxx flash will sometimes be
viewed as a USB memory device by a PC host.


Bill Wiese
San Jose, CA  USA