MMC/SD

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Revision as of 12:52, 28 July 2007 by JulienB (Talk | contribs) (Supported Cards)

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How-To connect an MMC/SD adapter/connector to your APF9328

For instructions on how to use MMC/SD on Linux, see MultiMediaCard page.
SDCard, MiniSD, and Transflash/MicroSD are all the same devices but in different package shapes and are all pin compatible.
On Armadeus boards, MMC are controlled in 1 bit MMC mode and SD/MiniSD/MicroSD in 4 bits SD mode. We don't use MMC/SD in "fucking slow & error prone" SPI mode.

Adapter board (for DevLight or your custom board)

We have designed a small adapter board with a push-pull MMC/SD connector on it. You need to connect the signals listed in the table below to the corresponding one on your DevLight board. The WP and CD_SW signals are optional and must be connected to free i.MXL GPIOs, if used.

Top view, connector on the left
Signals name (Top view with MMC connector on the right):
MMC Adapt pinout.jpg
Adapter Pin Desc Adapter Pin Desc
1 (square) +3.3V 2 SD_DAT2
3 SD_CMD 4 SD_DAT3
5 SD_CLK 6 SD_DAT0
7 WP (option) 8 SD_DAT1
9 CD_SW (option) 10 GND

Remarks:

  • Pin 1 (rectangular/square pad)
  • WP: write protect
  • CD_SW: Card Detect switch

If you don't want to buy such an adapter or don't have a MMC slot (and are a hacker ;-) ), you can still try this link:

On a DevFull board, there is already a MMC/SD connector

Supported Cards

Here is a list of the current cards which were tested:

MMC

Model Status Speed in kB/sec (read/write) Comments
Hama 256 Mbytes working 896 / 455 Ext2
NA

MMC+

  • Kingston 256MB -> OK

SD:

  • Kingston 512MB -> OK in 1bit mode. need more tests in 4 bits mode
  • Kingston 256MB -> OK
  • Dane-Elec 2GB -> OK in 1bit mode. doesn't work : Card recognized but partition table not found in 4bits mode
  • Transcend 2GB (x150) -> OK
  • Sandisk 512MB -> OK ( formating failure may happen sometimes. workaround: retry )

MiniSD:

Model Status Speed in kB/sec (read/write) Comments
Corsair 1Gbytes working 3339 / 365 VFAT
Sandisk 1Gbytes working
Sandisk 512Mbytes working
Transcend 512Mbytes not recognized NA
Extreme Memory 512Mbytes not recognized NA
Dane-Elec 1Gbytes doesn't work NA Card recognized but partition table not found

microSD/TransFlash:

Model Status Speed in kB/sec (read/write) Comments
Sandisk 512Mbytes working 3340 / 322 VFAT
NA

Test method

# dd if=/dev/urandom of=/tmp/data.bin bs=1024 count=3072
# mount /dev/mmcblk0p1 /media/mmc/
# echo "mv /tmp/data.bin /media/mmc/" > /tmp/test_mmc.sh
# echo "sync" >> /tmp/test_mmc.sh
# echo "exit 0" >> /tmp/test_mmc.sh
# time sh /tmp/test_mmc.sh
# umount /media/mmc && mount /dev/mmcblk0p1 /media/mmc/
# time cp /media/mmc/data.bin /tmp/data_read.bin


Links


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