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SD card in SD bus mode

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timsanr

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Hello,

I try to initialize SD card in High Speed mode. Steps I've done (sended commands) and which are correct: CMD8, repeating CMD55 and ACMD41, CMD2, CMD3, CMD7, CMD55, ACMD6 and finally CMD6.
All commands responses come back on CMD line and everything was OK, but response to CMD6 comes on DAT lines. Then turned out that DAT lines are pulled down since clock signal is sended to card. I see response to CMD6 (high level on data lines) but don't know when it starts. In specification is that CMD6 response is like block reading from SD so DAT lines should be in high level and data starts with '0' bits. DAT lines are connected with pull-up 62k resistors to 3.3V.

Any idea what could be wrong?
 

timsanr

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I have found my mistake. It was because of wrong tri-state buffer usage on FPGA. You can remove that thread :)
 

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