Sd file system speification.

Check out my last post to this ng. It has the websites for information pertaining to SD cards.

Hello,

I coudnt find the "Filesystem specification" in your postings. although the files in your last posting were useful. If you know where it is, could you post ti here?

Thanks in advance

Look for a document on the Sandisk website called "SDDK-05.R1.doc". It describes the SDDK for the SD driver and filesystem used on the SD cards. It describes the functions of the various libraries in the DDK, however does not give any source code to those libraries. I priced the cost of the full SDDK-05 early this year, and was quoted AU$10,000.

In an Atmel contest run by Circuit Cellar, some people built a FAT16/32 filesystem driver for AVR.

| Hello, | | I am working on interfacing an SD card to a microcontroller. | I need to read the SD card filesystem speicification v1.01. If anyone | of you has it , could you please post it or email it to me ? | I would be grateful to you for the same. | | Thanks in advance, | Ted

My suggestion would be to make a few test files to store on the SD card. If there's only one filetype that you'll be storing (i.e. say you'll only be putting .bmp images on it) make a few small test .bmp files of various sizes and upload them on the SD card.

Then have the microcontroller read back the raw bits to your computer, and analyze the result with a hex editor. See what sort of header information/checksum info is stored. Since you know the filetype, you can discard the header info, and if it's something that you can put up with a few errors once and a while then you can discard the checksum too.

Anyone think this would work? Whatever you do, be sure to have a backup plan (i.e. use MMC instead).

--
MT

To reply directly, take every occurrence of the letter 'y' out of my
address.

Hi,

i want to write data onto an SD card without any filesystem at first. i.e writing data onto an SD card without any filesystem driver.

My idea is like this

every sd card is paritioned into various sectores based on the below or close to it.

0x0000 MBR ( or whatever)

0x3333 FAT

0X4444 SOMETHING ELSE .... ........ 0x9999 DATA

what i want to do is to jump 0x9999 to write data there ...

I can seek that cluster /sector 0x9999 by doing this...

First i format the SD card usign an USB card reader and write the text string "FREE" to all its data area until the card is full

• then i search for the for the cluster from the beginning of the card until i find the text string "FREE" on it..

Id like to hear from you if you have any better idea for just writing a datastream onto an SD/MMC.. withoutu any filesystem... Thanks in advance, ted.

| Hi, | | i want to write data onto an SD card without any filesystem at first. | i.e writing data onto an SD card without any filesystem driver. | | My idea is like this | | every sd card is paritioned into various sectores based on the below or | close to it. | | 0x0000 MBR ( or whatever) | | 0x3333 FAT | 0X4444 SOMETHING ELSE | .... | ........ | 0x9999 DATA | | what i want to do is to jump 0x9999 to write data there ... | | I can seek that cluster /sector 0x9999 by doing this... | | First i format the SD card usign an USB card reader and write the text | string "FREE" to all its data area until the card is full | + | then i search for the for the cluster from the beginning of the card | until i find the text string "FREE" on it.. | | Id like to hear from you if you have any better idea for just writing a | datastream onto an SD/MMC.. withoutu any filesystem... | Thanks in advance, | ted.

Go here,

They have source code for writing to an MMC card. Download the .zip file and have a look at MMC.lib and Log.bas.

The MMC.lib shouldn't be too difficult to convert to whatever architecture you're using.

Goodluck!

--
MT

To reply directly, take every occurrence of the letter 'y' out of my
address.

HI all, I found some links here...

( SD file system and device driver )

( SD card Product manual )

( SD audio development kit)

Hope they might be useful to you....

| HI all, | I found some links here... | |

( SD file system and | device driver ) | | ( SD card Product manual | ) | | ( SD audio development | kit) | | | Hope they might be useful to you....

I haven't gotten around to looking at these yet.

Have they been helpful?

--
MT

To reply directly, take every occurrence of the letter 'y' out of my
address.

I guess they are useful in some way....

ha scritto nel messaggio news: snipped-for-privacy@z14g2000cwz.googlegroups.com...

A "simplified" version of the official spec is downloadable free of charge from SDCard.org website.

Bye.