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Question asked by cordez on Jul 4, 2018

Hi, I have an ADSP-BF609 EZ-BOARD and am having issues with the SD/MMC interface.

It works fine with regular SD cards of various sizes using the POST application but fails on MMC devices when detecting the 8-bit bus width.


The POST detects that an MMC card after failing to detect an SD card and then proceeds tot est the bus width. The test passes on 1-bit and 4-bit bus width detection but fails the test for 8-bit bus width detection even though the device is 8-bit compatible (Kingston KE4CN2H5A 4GB eMMC connected tot he MMC interface through a custom adaptor). The same occurs with an MMC card (non eMMC) inserted into the card interface. The test writes a pattern to the card on all 8 bus pins and reads it back to check for an inversion for the 8-bit test but it is always the same pattern and hence fails the test. My suspicion is that the driver software for this has a problem and that the 8-bi MMC interface has never been tested on the eval board. 


Any insights would be greatly appreciated.


Thanks in advance.