AnsweredAssumed Answered

SDIO block transfers stop too soon

Question asked by Nate Sigrist on Oct 21, 2014
Latest reply on Feb 9, 2017 by Chao Xu

I'm working with the MK64FN1M and I am having issues with SDIO block transfers using CMD53 (command).  Up till now I have had no problems sending commands and byte transfers.  I am using 1-bit at 400 KHz baud, 1 block, 128 bytes, 128 >> 2 for the watermark, and card detect disabled on both ends.

 

I've connected a scope and can confirm that data is being sent and received on the SDIO DAT0 pin.  I can also confirm that the command sent is correct on the command pin and that the data transmitted or received is the correct binary data that I am sending or expecting to receive.

 

The issue is that the data being sent is only around 14 bytes + the 2 byte CRC.  When receiving data, again, the clock only runs long enough to receive 16 bytes and afterwards the IC holds the data line low.

 

Is this a flaw in the MK64FN1M0VLL12?  Am I missing anything or is there a workaround?

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