SDHC questions

Hi there,

I need the SDHC spec cause I got to adapt existing embedded code to
support the HC cards.
neither google nor Sandisk helped. Any ideas where to get the spec
from would be highly appreciated.

Do ordinary built in SD card reads in laptops support SDHC?

Is there anything out for cards beyond 32 GB ?

tia
w.b.

On Mon, 18 Feb 2008 01:19:26 -0800 (PST), analox <analox@gmx.de>
wrote:

>I need the SDHC spec cause I got to adapt existing embedded code to
>support the HC cards.

Google for
  SD Host Controller Standard Simplified Specification

Stephen


-- 
Stephen Pelc, stephenXXX@mpeforth.com
MicroProcessor Engineering Ltd - More Real, Less Time
133 Hill Lane, Southampton SO15 5AF, England
tel: +44 (0)23 8063 1441, fax: +44 (0)23 8033 9691
web: http://www.mpeforth.com - free VFX Forth downloads

"Stephen Pelc" <stephenXXX@mpeforth.com> wrote in message 
news:47b98c22.338328140@192.168.0.50...
> On Mon, 18 Feb 2008 01:19:26 -0800 (PST), analox <analox@gmx.de>
> wrote:
>
>>I need the SDHC spec cause I got to adapt existing embedded code to
>>support the HC cards.
>
> Google for
>  SD Host Controller Standard Simplified Specification

I suspect that the OP is not interested in the Host Controller spec, but the 
High Capacity spec. I don't think that there is one though. It is part of 
the SD Spec version 2, which wasn't publicly available last time I looked. 
However, I have managed to figure this out myself. The basic differences 
are:

* In the initialization at ACMD41 say you support SDHC (0x40000000).
* In the CMD55 the reply should include SDHC support (0x40000000).
* All sectors are 512 bytes and can't be changed by CMD16.
* Offsets for reading and writing sectors are now sector numbers not bytes. 
So in theory you can access cards with 512x mory memory.
* And the file system (as supplied) is FAT32.

I'm sure there is other stuff that I didn't need.

Peter 

On Tue, 19 Feb 2008 07:48:50 GMT, "Peter Dickerson"
<firstname.lastname@REMOVE.tesco.net> wrote:

>I suspect that the OP is not interested in the Host Controller spec, but the 
>High Capacity spec. I don't think that there is one though. It is part of 
>the SD Spec version 2, which wasn't publicly available last time I looked. 
>However, I have managed to figure this out myself. The basic differences 
>are:

What you need for HD is in the initialisation sequence diagrams.

However, as always reality intervenes when you test cards from
several different suppliers.

Stephen


-- 
Stephen Pelc, stephenXXX@mpeforth.com
MicroProcessor Engineering Ltd - More Real, Less Time
133 Hill Lane, Southampton SO15 5AF, England
tel: +44 (0)23 8063 1441, fax: +44 (0)23 8033 9691
web: http://www.mpeforth.com - free VFX Forth downloads