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SD CMD7 Time out error

Question asked by Vianney Monestel on Sep 11, 2014
Latest reply on Sep 24, 2014 by CarlosCasillas
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I have been working on a SD controller for the imx6SDL. I am testing and debugging the initialization, however it is not working, this happens when I issue CMD7 to enter to transfer state. When I check for any error on the Interrupt Status Register after the command is sent, I got a Command Timeout Error and Command Index Error and I have not been able to discovered the problem. I issue some other commands (CMD0, CMD8, CMD55, ACMD41, CMD2, CMD3) and I did not find any error. Before sending this command, I clear the Interrupt Status Register fields (CC, CTOE, CCE, CEBE, CIE), also it is important to mention that I got 0x80700 in Command Reponse 0 Register.


This is the way I set the instance registers:


Command Index = 7

Argument = Card Relative Address (0x7 << 16)

Response Type Select (Command Transfer Type Register) = Response Length 48, check Busy after response (0x3)

Data Transfer Direction Select (Mixer Control Register) = 1 (Read)

Data Present Select (Command Transfer Type Register) = 0 No Data Present

Command Index Check Enable (Command Transfer Type Register) = 1 Enable

Command CRC Check Enable (Command Transfer Type Register) = 1 Enable.


As I mentioned before, I did not get any error on other commands, the SD card is successfully detected however I can not enter to transfer state to start transmitting data. I really appreciate any suggestion that can help me to solve my problem.



Vianney Monestel