AT89C52 interface SD Memory Card

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Which datasheet are you referring to? Is it titled,
"SanDisk Secure Digital Card, Product Manual, Version 1.9, Document No. 80-13-00169, December 2003" "

yes, you are correct...

I don't know about reading a single byte, I have never done this.

According to the manual:

The only valid block length for write is 512 bytes. The valid block length for read is 1 to 512 bytes. A set block length of less than 512 bytes will cause a write error. The card has a default block length of 512 bytes. CMD16 is not mandatory if the default is accepted.

I always use 512 sized blocks...

okay, Dave...

Hello Ajay,

Where are you going to post the tutorial. It would be very useful for many of beginners like me. Please give me the link.

Hello friends,

I found something by interesting. Can you help me to figure it out.
1. At first I created three different files(.txt,.doc,.csv) in my computer and then copied them into my sdcard.
2. I created a newtext document in sd card itself with out changing the name.
3. I created a newtext document in sd card and changed its name to test.txt
4. I created a word document in sd card with praveen.doc
5. I created a csv file with name dave.csv
i found somechanges in sector 4153 where the iinformation about my files are getting stored. can you please help me to figure it out.

The changes are normal. They occur when you create / delete files.

Please read the definition of the Directory Table at this address

http://en.wikipedia.org/wiki/File_Allocation_Table

Regarding the directory entries, specifically the filename:

DOS file name (padded with spaces)
The first byte can have the following special values:

0x00 Entry is available and no subsequent entry is in use
0x05 Initial character is actually 0xE5
0x2E 'Dot' entry; either '.' or '..'
0xE5 Entry has been previously erased and is available. File undelete utilities must replace this character with a regular character as part of the undeletion process.

Is this what you are referring to?

Regards,

-Dave

Dear Daves and shiva,

I’m back again. Sorry for disappear so long… Actually I’m checking my coding and study how the chan passing the argument to the function. Currently, I’m not so confident about my coding. Before go into FAT system too deep please can you guide me how to do the basic things to ensure my coding is fine? I have testing in practical it look fine. I still stack at Wed Feb 11 2008, 02:03AM discussion.
:blush
Thank you,.

Have dave, if possible please make a writeup and mail me.. I will convert it into html tutorial for others you are the only person who has done it successfully (True, I am not flattering you ) writeup need not to be exact even a bad written text will also work. I will format it properly to make everyone understand.

Will be waiting for your mail

I'll see what I can put together...

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