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SDIO command CRC error on ACMD41

Question asked by Jack Peacock on Nov 7, 2011
Latest reply on Nov 18, 2011 by Kamenicky.Tomas
When single stepping through the initialization commands for the SDIO card socket (STM3210E) I notice that ACMD41 always returns a command CRC error flag.  The ST example code specifically ignores the CCRC FAIL flag when it processes the status register.  The ST example code doesn't ignore CRCs (or lack of CMDREND bit set due to CRC error) on other commands.  Is there a reason for this, something undocumented in the SDIO interface?  I do get a valid OCR register in the response.

In my own code I issue CMD2 to get the CID right after the ACMD41 to set the OCR.  I get a CTIMEOUT instead of CMDREND consistently.  Does this mean the OCR command  fled and put the card in an inactive state?  Is there something that has to occur bettwen setting OCR and reading CID?

Memory card is SDHC, 4GB PNY card.  I dont see the CCS bit set (for SDHC cards) in the OCR either.  I do see flags set for voltage range and BUSY is cleared.

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