Strange problem, sdhc card got intialized with debugger otherwise not

[aamirali641989]

Posted on July 08, 2013 at 08:44

I have interface SDHC card with SPI protocol.

If I initialize the card while debugging it worked right. 

But if initialize it without it then card don't get initialized.

What could be the problem, like some timing issues. I also added 10ms delay b/w spi initialization & card initialization but didn't work.

Its timeout when I send CMD55_APP_CMD & ACMD41_SEND_OP_COND command

[aamirali641989]

Posted on July 10, 2013 at 11:59

Any help on this. 

[frankmeyer9]

Posted on July 10, 2013 at 12:23

Hard to give a useful hint, without your hardware.

I would add debug output, redirected to a uart, to find the difference.

You could record the return values of the failing function calls, and compare with that seen during debugging.

What could be the problem, like some timing issues.

 

I suspect a timing problem, too.

Have you tried lower bit rates ?

Have you compared your implementation with other, working examples ?

[John F.]

Posted on July 10, 2013 at 12:42

Did you follow these steps?

http://elm-chan.org/docs/mmc/mmc_e.html

Chan's web site is usually very reliable.