MicroSD Cards and SDHC compatibility

[Chris_UTS]

Hi

I have been following the SD card examples provided with MQX 3.4 and have had had the following results:

1) 256 MB MicroSD Card (Non SDHC) - Works perfectly.

2) 2 GB MicroSD Card SDHC - Detects card but unable to read directory or format.

3) 8 GB MicroSD Card SDHC - Detects card but unable to read directory or format.

I understand there is a different initialization routine for the SDHC cards. Does anyone know if this has been factored into the current driver? If not, will it likely be included with future MQX releases or should I just develop my own modified driver?

Has anyone had any other experiences with MQX and SDHC cards before?

Thanks

Chris

[VectorSucess]

Hi,

I guess the problem with SDHC compatibility is about the source code of SD card is writed to 1.0 Physical Layer of SD cards or Stardart Layer. I have the same problem with DRM104SW with SD_CARD_READER when i use cards more then 2Gbytes. I guess the new physical layer is diferent, by the way, the CSD DataSize byte information is in other adress inside of the memory and had 21 bytes of information on SDHC Cards diferent of 16bytes of old layer.

http://www.sdcard.org/developers/tech/sdcard/pls/Simplified_Physical_Layer_Spec.pdf

[PetrM]

Hello,

SDCARD driver really supports SDHC v.2.0.

The problem is in MBR (sector 0) of the cards.

Please visit this section for more information:

https://community.freescale.com/thread/61983

PetrMhttps://community.freescale.com/thread/61983" jivemacro="thread" title="

[javax]

Hi everybody

I want to try  demo  "mfs_sdcard_twrmcf51cn" in the TWMCF51CN128. I have been working with

Code Warrior 10 (Eclipse based). It is no clear how I can attach a SD or microSD card at the Tower

so I really appreciate any help or guide.

thanks

[PetrM]

There is twr-mem board available which is SD card ready:

http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=TWR-MEM

Or wire the SD card slot yourself using 51CN's SPI2 module - check the twr-mem schematics on the page above.

PetrM

[chogh]

Hi Petr,

I'm also trying to use the MQX 3.7 MFS sdcard example (Freescale MQX 3.7\mfs\examples\sdcard) using the TWRK40x256 tower board and IAR Systems Embedded Workbench 6.2, but I get an error when it tries to open a file handle.  Have you seen this issue before, or can you point me in right place to look?  I've attached some screen shots.  I'm trying to use the SD card on the TWRK40x256 main board, not the TWR-MEM board.

Thanks for your help,

Chris

[chogh]

I figured out my problem.  I just reread the "FSL_MQX_Getting_Started.pdf", particularly the "2.1.1 Build Process" section, updated the correct user_config.h file (the one in the /config/twrk40x256 folder), recompiled the libraries, then recomplied my project, and everything worked!  It's a happy Friday.

-Chris

[PetrM]

Hi,

SD card driver supports SDHC format. It can read the size and other parameters of the card.

So first make sure it's formatted to FAT32 - MFS supports only this filesystem for such big media.

There were also few bugs in MFS and they will be solved in next release (MQX 3.5).

Anyway I am able to use micro SDHC card of 16 GB size with this release.

PetrM

[Chris_UTS]

Hi PetrM,

Thanks for your response. 

I've done some more investigation and found that MQX (3.4) is having a problem recognising the filesystem when the microSD card is formatted with FAT32. I managed to trick windows into formatting the 8GB SDHC into a 256MB FAT16 partition, and MQX was able to read the file system on the SDHC card perfectly.

Can you think of any marcos/settings that may need to be defined to enable FAT32 operation on MQX?

Can I also ask what processor you have used to read the 16 GB card?

Thanks,

Chris

**EDIT: I've just reformatted the 8GB card using windows xp and it appears to be working now, however my 4GB card is still not being recognised. I suspect this may be an issue with how the device is initially formatted by the manufacture. I will hopefully be able to investigate further in the next couple of days. 

Message Edited by Chris-UTS on 2010-01-20 01:18 PM

[PetrM]

Well, you can't force the FAT32 format, everything is read out from the boot sectors and card registers.

So it's a matter of proper formatting - I was also successful with windows xp format tool.

I was testing the card on twrmcf51cn (mcf51cn128) and twrmcf52259 (mcf52259).

I recommend to wait for MQX 3.5 which will be soon and should solve the rest of the problems.

PetrM