Hello,

Inside the microSD flash memory, and SD flash memory, there is a bit, that
once programmed, the data inside the chip becomes write-protected, and
permanent. I searched for a tool that can program this bit, but I did not
find any. Do you know of such a tool? Or driver? Or Software? Any
thought on this will help me. Thank you very much.

Best Regards,
T.I.

In article <uHvyh.113350$h75.14275@trnddc01>, "Talal Itani" <titani@verizon.net> wrote:
The easiest way to access the registers inside an SD card is to talk directly
to the card through an SPI interface using some microcontroller. If you don't
have one handy, Olimex sells a prototype board that includes an LPC2148
microcontroller and an SD socket already connected to the SPI port. The part
number for the board is LPC-P2148 and you can get it from www.olimex.com
for about $75. There are probably other proto boards that are cheaper and
easier to work with but this is the first one that came to my mind.
Regardless of which proto board you buy, you will have to write your own
software to access that particular register.

--Tom.

On Thu, 08 Feb 2007 06:00:42 +0000, Tom wrote:

Some example code can be found on the internet for general writing to a
mmc with spi. Quickest route might be to start with that, to see how
others have done it, and then add in the functionality that you need. It
shouldn't be a big task to do - it's pretty straightforward to do. The mmc
documentation that I have seen (which mmc manufacturers all seem to base
their card specs on), is very badly written though - if you like reading a
document to get an understand/information quickly, then the MMC
documentation doesn't fit that bill.

Also note that SD cards are not *completely* compatible with MMC cards -
there are differences. Ideally you would want to get hold of a SD
technical spec, but when I looked they were hard to come by so I got by
with a mmc card spec. I did find one incompatibility with mmc, but I
worked around it - they are *mostly* compatible in SPI mode.

Why the sd people make their docs so difficult to get hold of is beyond me
- after all, talking to such a card only needs a small simple little
protocol, nothing highly innovative. Not really something I would consider
being too secretive about. I'm sure they can have done something in a
license that protects their financial interests and still opens up specs.

Good luck,

Paul.

You know, when I first read your reply, I thought, that your recommendation
is not the easy way to set that bit in the SD memory. I wanted to use
Windows, with the SD card attached to the PC, and write PC software. But
the more I looked at the Windows solution, the more I find out that your
recommendation is a good one. I think I will pursue what you told me.

"Tom" <tom8192@hotmail.com> wrote in message
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