Lpc2000

Hello,

The system has a lot of buffering going on for the file system work. 
Old firmware did write every time you call fputchar() This makes the 
system better in case of power loss but it was very slow, about 
5KB/S. Then we decided to change that. Now, ALFAT buffers the data 
and only writes when a full sector is full. The disadvantage is that 
you have to close the files before you shut down the system or you 
have to flush the data every few milliseconds ( this will be 
automatic in future)

There is no stall time because we have 256-byte buffer for UART and 
SPI so even if ALFAT is saving a sector it will still keep your 
commands and data in FIFO till it is ready. Now 70KB/S is when a 
media is not fragmented a lot and for a media that is still fairly 
new. FLASH seems to slow down after a long use. But if you are 
looking into 50K then that should be no problem at all.

All the best,

Gus
www.ghielectronics.com

--- In lpc2000@yahoogroups.com, "Lasse Madsen" <lasse.madsen@e...> 
wrote:
> Hi Gus
> 
> Does your file system write a packet at a time (512 bytes) or do 
you
> write along the way for instance 
> 
> For ( x = 0 ; x < 1024 ; x++ )
> fputchar('U');
> 
> You claim 70KB/s on your system but how is this measured according 
to
> the above example ... will the file system save a packet when x = 
512 or
> save along the way (x=1,x=2,x=3..) if you write a packet at a time 
I
> would say its difficult to determine the actual speed as you will 
have a
> "stall" time when writing the packet and a buffer overflow could 
occur
> while writing the packet if you catch my draft ? 
> 
> Regards
> Lasse Madsen
> 
> 
> 
> 
> -----Original Message-----
> From: Gus [mailto:gus_is_working@y...] 
> Sent: 27. september 2004 18:35
> To: lpc2000@yahoogroups.com
> Subject: [lpc2000] Re: FAT file system
> 
> That is funny! I never posted the website :-)
> www.ghielectronics.com
> 
> By the way ALFAT is doing 70KB/S now! We also added 256 FIFO to 
UART 
> and SPI
> 
> 
> --- In lpc2000@yahoogroups.com, "Pete" <peterbrown_abroad@y...> 
> wrote:
> > Hi Gus
> > Actually having fat32 is OK, its just that for our particular 
> > embedded application we will NEVER exceed something like 
100Mbyte. 
> > If my understanding is correct then fat16 can handle this ok.
> > We also do not need to support long filenames as this is an 
> embedded 
> > product.
> > The only time we need to interface to the PC is when we upload 
the 
> > data onto the flash card at production, or during inservice 
> product 
> > upgrades.
> > 
> > If you could point me to a website or similar for info on the 
> system 
> > you have then that would be great.
> > 
> > We will be starting to lay out PCB out shortly for the main 
> > controller and as such we may not need to get the board you 
have - 
> > so is just the source code available to purchase for fat file 
> system 
> > and interface to a compact flash card?
> > 
> > thanks for your help,
> > rgds
> > pete
> > 
> > 
> > --- In lpc2000@yahoogroups.com, "Gus" <gus_is_working@y...> 
wrote:
> > > Peter,
> > > 
> > > Yes, board and chips are available. Why you don't want FAT32? 
> did 
> > > you think that at some point in the future you will need a 
> larger 
> > > media that is FAT32?
> > > 
> > > Thanks,
> > > 
> > > Gus
> > > --- In lpc2000@yahoogroups.com, "bty639886" <peter.brown@b...> 
> > wrote:
> > > > Gus,
> > > > Is your dev board available?
> > > > Is the ALFAT software available?
> > > > 
> > > > I require compact flash read/write only (no need for fat32)
> > > > 
> > > > Please advise,
> > > > Kind Regards,
> > > > 
> > > > Peter
> > > > 
> > > > --- In lpc2000@yahoogroups.com, "Gus" <gus_is_working@y...> 
> > wrote:
> > > > > I have posted about this before but now I am finally done 
> with 
> > > > > ALFAT. I used LPC2114 chip and programmed it with full FAT 
> > file 
> > > > > system where you can send SPI or UART(serial) commands to 
it 
> > and 
> > > > it 
> > > > > will save FAT files to many kinds of medias SD, MMC, CF 
and 
> > hard 
> > > > > disks!
> > > > > 
> > > > > The development board can be used for other purposes as it 
> has 
> > > > > LPC2114, RS232 level converter, MMC/SD/CF connectors, and 
> IDE 
> > > > header 
> > > > > for your hard disk!
> > > > > 
> > > > > Thanks for your time,
> > > > > 
> > > > > Gus Issa
> > > > > gissa@g...
> 
> 
> 
> 
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