TS-4900 MicroSD Card Interface

From embeddedTS Manuals
Revision as of 11:00, 30 March 2015 by Mark (talk | contribs)

The i.MX6 SDHCI driver supports MicroSD (0-2GB), MicroSDHC (4-32GB), and MicroSDXC(64GB-2TB). The cards available on our website on average support up to 16MB/s read, and 22MB/s write using this interface. The linux driver provides access to this socket at /dev/mmcblk1 as a standard Linux block device.

This graph shows our SD write endurance test for 40 TS-7553 boards running a doublestore stress test on 4GB Sandisk MicroSD cards. A failure is marked on the graph for a card once a single bit of corruption is found.

See chapter 67 of the IMX6 reference manual for more information on this mmc controller.

We have performed compatibility testing on the Sandisk MicroSD cards we provide, and we do not suggest switching brands/models without your own qualification testing. Though SD cards in theory will all follow the standard and just work, in practice cards vary significantly and can fail in subtle ways. We do not recommend ATP or Transcend MicroSD cards specifically due to known corruption issues that can occur after many GB of written data.

Our testing has shown that on average microSD cards will last between 6-12TB of written data before showing a single bit of corruption. This is enough for most applications to write for years and not see any issues, but for more reliable consider the eMMC which is expected to last over 100TB of writes.